From: Robert L Barns <75612.2635@..............> Subject: Geophones Date: Mon, 30 Jun 1997 20:19:59 -0400 Hi gang, I just got the current catalog of Mitcham Industries (www.mitchamindustries.com). Among the large list of wild and wonderful= seismic equipment (some around $500,000) is "3 Hz l15B single phone w/Muller clip". They have 50 for $25 ea. (This is more like my price range.) They have a bunch more with higher freq. cut-offs. I know nothing about these things but will buy one to play with. Two questions:1. What is a Muller clip? and 2. Where can I get pin-outs etc= =2E so that I can hook it up. I think that someone on this list stated that these things are vertical= s unless otherwise labeled. Bob Barns _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson Subject: Re: Geophones Date: Tue, 01 Jul 1997 12:31:27 +1200 Bob I spoke to the CEO of Mitchum two weeks ago and unfortunately the L15B's are sold out and will not be replaced because Mark products who supplied them no longer make that model. The Muller clip is just a small forcefit clip that slides onto the two contact prongs of the seismometer there are only to pins on the seismometer and they just go straight to the input of your preamp Dave N. At 08:19 PM 6/30/97 -0400, you wrote: >Hi gang, > I just got the current catalog of Mitcham Industries >(www.mitchamindustries.com). Among the large list of wild and wonderful >seismic equipment (some around $500,000) is "3 Hz l15B single phone >w/Muller clip". They have 50 for $25 ea. (This is more like my price >range.) They have a bunch more with higher freq. cut-offs. > I know nothing about these things but will buy one to play with. Two >questions:1. What is a Muller clip? and 2. Where can I get pin-outs etc. >so that I can hook it up. > I think that someone on this list stated that these things are verticals >unless otherwise labeled. >Bob Barns > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm Q-BIT'SLAWNo.9: INTERCHANGEABLEPARTS-WON'TBE Q-BIT'SLAWNo.10: ANY WIRING ERRORINANYCONSTRUCTIONWILLBEIN THE DIRECTION OF THE MOST DAMAGE Q-BIT'SLAWNo.13:IDENTICALPARTSAREN'T _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson Subject: Re: Geophones Date: Tue, 01 Jul 1997 12:50:52 +1200 Bob, further to my last message, Jim Croix, of Mitchum, informed me that they do have this model available SHEARWAVE 4.5 HZ LITTON Each $35.00 NOTE anything you see on their list stated as " SHEARWAVE " is a HORIZONTAL geophone at 4.5 Hz these are the same as the ones I am using here in New Zealand. Dave N. At 08:19 PM 6/30/97 -0400, you wrote: >Hi gang, > I just got the current catalog of Mitcham Industries >(www.mitchamindustries.com). Among the large list of wild and wonderful >seismic equipment (some around $500,000) is "3 Hz l15B single phone >w/Muller clip". They have 50 for $25 ea. (This is more like my price >range.) They have a bunch more with higher freq. cut-offs. > I know nothing about these things but will buy one to play with. Two >questions:1. What is a Muller clip? and 2. Where can I get pin-outs etc. >so that I can hook it up. > I think that someone on this list stated that these things are verticals >unless otherwise labeled. >Bob Barns Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm Q-BIT'SLAWNo.9: INTERCHANGEABLEPARTS-WON'TBE Q-BIT'SLAWNo.10: ANY WIRING ERRORINANYCONSTRUCTIONWILLBEIN THE DIRECTION OF THE MOST DAMAGE Q-BIT'SLAWNo.13:IDENTICALPARTSAREN'T _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Doug Crice Subject: Re: Geophones Date: Mon, 30 Jun 1997 21:45:46 -0700 If you go to the geospace home page at http://www.geospacecorp.com/gs11d.htm you can see pictures of geophones. There's no scale in the picture, but they are about 1 inch diameter and 1.25 inches long. The schematic is a coil of wire (in a magnetic field) with two terminals. I'm afraid David used a New Zealand accent when describing a Mueller clip. A Mueller clip is one of those temporary test lead clips in the same class as "alligator clips", except that the teeth are bite shaped and made to connect with a contact that looks exactly like a coil spring. They are called Mueller clips after Mueller the manufacturer. They have red and black insulators and come in two different widths, which mate with two adjacent springs of different widths molded into a multi-conductor geophone cable. There is another common connector called the "split spring" or split ring. They look like those fuse holders you see nounted on circuit boards. There are also a family of waterproof connectors sometimes used in marshy situations. The reason geophones are described with their connector is so that the potential buyer can know if they will match the cables he has. Yes, geophones are vertical unless noted as horizontal or shear phones. Doug Crice _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: John Hernlund Subject: Re: Geophones Date: Mon, 30 Jun 1997 23:44:54 -0700 (MST) Robert, Could you send me the address of that company so that I could request a catalog? ****************************************************************************** John Hernlund E-mail: hernlund@....... WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ ****************************************************************************** On Mon, 30 Jun 1997, Robert L Barns wrote: > Hi gang, > I just got the current catalog of Mitcham Industries > (www.mitchamindustries.com). Among the large list of wild and wonderful > seismic equipment (some around $500,000) is "3 Hz l15B single phone > w/Muller clip". They have 50 for $25 ea. (This is more like my price > range.) They have a bunch more with higher freq. cut-offs. > I know nothing about these things but will buy one to play with. Two > questions:1. What is a Muller clip? and 2. Where can I get pin-outs etc. > so that I can hook it up. > I think that someone on this list stated that these things are verticals > unless otherwise labeled. > Bob Barns > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Strange event... Date: Mon, 30 Jun 1997 23:58:36 -0700 Greetings, Yesterday my SDR systems when into alarm around 6/30/97 16:28 UTC. All of the USGS sensors that I monitor, and my S-G sensor, picked up the event. The problem is I can't find it on any of the Internet location services. The seismograms look like the P wave of a large teleseismic event with all of the waves near 2 hz but I can't see or find any matching S or long period surface waves. The closes event I can find is the Mb5.3 in Hawaii but it happened at 15:47. That's to early for the travel time of P wave and to high of a frequency for the S and long period surface waves. It's also to high of an amplitude for a 5.3 that far away. Anyone else get something around that time? This is a strange one... Regards, Larry Cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson Subject: Re: Geophones Date: Wed, 02 Jul 1997 00:43:01 +1200 John they have a online catalog along with online ordering facilities at http://www.mitchamindustries.com Dave N. > Could you send me the address of that company so that I could request >a catalog? > >****************************************************************************** > > John Hernlund > E-mail: hernlund@....... > WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ > >> Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm Q-BIT'SLAWNo.9: INTERCHANGEABLEPARTS-WON'TBE Q-BIT'SLAWNo.10: ANY WIRING ERRORINANYCONSTRUCTIONWILLBEIN THE DIRECTION OF THE MOST DAMAGE Q-BIT'SLAWNo.13:IDENTICALPARTSAREN'T _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: ct@....... (Charlie Thompson) Subject: Re: Strange event... Date: Tue, 01 Jul 1997 10:12:15 -0500 Larry, I did see something strange but I didn't note the time. I'll look again when I get home from work. Keep in mind that there was a volcanic event in Mexico City that spewed ashes 40,000 feet into the air and closed Mexico City Airport. I think the event was yesterday. -Charlie >Greetings, > >Yesterday my SDR systems when into alarm around 6/30/97 16:28 UTC. All of >the USGS sensors that I monitor, and my S-G sensor, picked up the event. >The problem is I can't find it on any of the Internet location services. >The seismograms look like the P wave of a large teleseismic event with all >of the waves near 2 hz but I can't see or find any matching S or long >period surface waves. The closes event I can find is the Mb5.3 in Hawaii >but it happened at 15:47. That's to early for the travel time of P wave and >to high of a frequency for the S and long period surface waves. It's also >to high of an amplitude for a 5.3 that far away. > >Anyone else get something around that time? This is a strange one... > >Regards, >Larry Cochrane >Redwood City, PSN > > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > ------------------------------------------------------------------------- Charlie Thompson WB4HVD 30.112N 97.891W 800 Elliott Ranch Rd. Buda, TX 78610 http://www.onr.com/user/ct/ct.html Seismic Station .BUE _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Dennis Leatart Subject: Re: Strange event... Date: Tue, 01 Jul 1997 08:53:22 -0700 I picked up this event also- I have not downloaded it yet-- but if anyone needs to look at it -- it is about 26K in bmp format. -- _____ __ | \.-----.-----.-----.|__|.-----. | -- | -__| | || ||__ --| |_____/|_____|__|__|__|__||__||_____| _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Phil Giannini" Subject: Strange Event Date: 1 Jul 1997 09:08:45 U REGARDING Strange Event Hi Guys, Yes I got it too, but didn't put it up yet because I was waiting for a comformation from one of the USGS sites. I will put it up tonight when I get home. Maybe if enough of us have it we can figure out where it came from. I received it on both of my sensors. Phil SFN SFZ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Charlie Plyler Subject: Re: Strange event... Date: Tue, 01 Jul 1997 12:25:18 -0400 Hello all, Whatever caused this event it was both electrical as well as seismic in nature. The 2hz wave form was very predominate on the East Coast. If anyone would desire an SDR file just let me know. Charlie Elfrad Group 35.728N 80.810W _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Martin Brewer" Subject: Re: Bermuda 'quake Date: Tue, 1 Jul 1997 18:24:08 -0300 Robert, I seem to have picked up a small event [M2.5] at 07/01/97, 21:12:36; 1.33 degrees (148km) from Bermuda [lat 32.3N, long 64.8W. Is there any chance you picked it up? Regards, Martin _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert L Barns <75612.2635@..............> Subject: Re: Bermuda 'quake Date: Tue, 1 Jul 1997 21:47:00 -0400 Martin, I agree that it is handy to have others in the area to check out the weird ones. We have a different set of problems compared to that mob around the Pacific. On 6/24 I got one that looked pretty good. The internet report was Indonesia, org. 23:4:53 m6.1 at 1.8S and 127.8E. From me 9380 mi, 135.6 deg. (No P or S expected from that dist.) I calc. that the LQ here shou= ld be 24:16 (sic) but the biggest waves started here at about 24:18 to 24:2= 7. It was rather strange in that the largest waves were not much bigger tha= n what came before. From that far away, things get scrambled up. Bob Barns _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Charlie & Terri Thompson Subject: Strange Event might be Hawaii Date: Tue, 01 Jul 1997 21:24:30 -0500 I recorded the strange event and went searching for a source.. here are the arrival times for the Hawaii Event into Buda, Texas. My peak waves arrived around 16:15 to 16:21 which is included in the arrival times below: DATE-(UTC)-TIME LAT LON DEPTH MAG Q COMMENTS 97/06/30 15:47:37 19.34N 155.06W 1.0 5.3Mb HAWAII delta azimuth (degrees clockwise from north) (deg) eq-to-station station-to-eq 52.56 66.5 272.1 travel arrival time # code time(s) dy hr mn sec 1 P 554.96 0 15 56 51 2 pP 555.28 0 15 56 52 3 sP 555.41 0 15 56 52 4 PcP 625.12 0 15 58 2 5 PP 673.94 0 15 58 50 6 PP 680.34 0 15 58 57 7 ScP 863.54 0 16 2 0 8 PcS 863.66 0 16 2 0 9 S 1003.67 0 16 4 20 10 pS 1004.06 0 16 4 21 11 sS 1004.21 0 16 4 21 12 PKiKP 1024.38 0 16 4 41 13 pPKiKP 1024.73 0 16 4 41 14 sPKiKP 1024.85 0 16 4 41 15 ScS 1146.10 0 16 6 43 16 SS 1223.23 0 16 8 0 17 SKiKP 1237.95 0 16 8 14 18 SS 1242.13 0 16 8 19 19 PKKPdf 1881.91 0 16 18 58 20 SKKPdf 2095.45 0 16 22 32 21 PKKSdf 2095.58 0 16 22 32 22 SKKSdf 2308.98 0 16 26 5 23 P'P'df 2384.51 0 16 27 21 24 P'P'bc 2401.56 0 16 27 38 25 P'P'ab 2426.24 0 16 28 3 26 S'S'df 3241.11 0 16 41 38 Thanks to John for the nice calculator! -Charlie Thompson Buda, Texas _ ________________________________________________ _ / ) | | ( \ / / | Charlie Thompson WB4HVD | \ \ _( (_ | _ e-mail: ct@....... _ | _) )_ (((\ \> |/ ) http://www.onr.com/user/ct/ct.html ( \| Subject: Re: Strange event... Date: Tue, 01 Jul 1997 19:51:43 -0700 At 11:58 PM 6/30/97 -0700, you wrote: >Greetings, > >Yesterday my SDR systems when into alarm around 6/30/97 16:28 UTC. All of >the USGS sensors that I monitor, and my S-G sensor, picked up the event. >The problem is I can't find it on any of the Internet location services. >The seismograms look like the P wave of a large teleseismic event with all >of the waves near 2 hz but I can't see or find any matching S or long >period surface waves. The closes event I can find is the Mb5.3 in Hawaii >but it happened at 15:47. That's to early for the travel time of P wave and >to high of a frequency for the S and long period surface waves. It's also >to high of an amplitude for a 5.3 that far away. > >Anyone else get something around that time? This is a strange one... > Larry- I am up the coast from you at Sea Ranch and I got it also. My computer is down but I got it on the drum recorder. The waves were of low frequency as you noted and I got them at about 16:05 (+- 5 minutes) UT. If you are interested, I can mail you the drum trace. George Bush _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Re: Strange event... Date: Wed, 02 Jul 1997 00:59:54 -0700 Hi George, I think you got the surface waves of the Hawaii event. The event I was taking about happened 25 minutes later. I received the surface wave of the Hawaii event around 16:04 UTC. -Larry At 07:51 PM 7/1/97 -0700, you wrote: >I am up the coast from you at Sea Ranch and I got it also. My computer is >down but I got it on the drum recorder. The waves were of low frequency as >you noted and I got them at about 16:05 (+- 5 minutes) UT. If you are >interested, I can mail you the drum trace. > >George Bush > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: More on the strange event... Date: Wed, 02 Jul 1997 01:24:58 -0700 Hi, I got this from David Wolny: >Date: Tue, 1 Jul 1997 10:25:17 -0600 (MDT) >From: David Wolny >To: cochrane@.............. >Subject: strange event >Hi Larry, >If you haven't gotten an answer yet, try this; >june 30 1997 16:29:04.4 38.2N 123.4 W Ml 2.8 depth 10 >You can get the info by phoning the NEIC and giving them the time that >you recorded the event. >Dave Thanks Dave, I think this is it. I was only 147km (79 miles) from the event and it would be big enough to register on my system at home and all of the USGS sensors I monitor. This event never showed up on any of the local (Berkeley or the Menlo Park USGS) finger servers. This is probably do to the fact that it was out in the ocean north west of me. The seismograms look different then a normal local 2.8, must be because of its location. Dave, did you get this info from the USGS phone system or somewhere on the NET? -Larry Cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: gchantler@....... (Gary Chantler) Subject: Q's on 6/17/97 Date: Thu, 3 Jul 1997 08:19:19 -0800 Hi all, its been awhile since I've written. :-( I've been looking at some gravity data and I was wondering if something (quake) happened on the 17 of June???? I see the Washington (W. coast) quakes clearly in the trace(23,24th), but I also see something on the 17th (Wish I could be more specific) and thought someone might have the time to respond. I also have another question. Was there some talk awhile back about mercury pendulum seismometers???? You can write back to the list or to me at gchantler@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert L Barns <75612.2635@..............> Subject: Re: Geophones Date: Thu, 3 Jul 1997 19:59:45 -0400 John Hernlund, Mitcham Industries, PO Box 1175 Huntsville, TX 77342-1175 409-291-2277 Bob Barns _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert L Barns <75612.2635@..............> Subject: Re: Bermuda 'quake Date: Thu, 3 Jul 1997 19:59:49 -0400 Martin, I see nothing at or near 7/1 21:12 although my noise level was high for= a few hours around that time. Bob _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Martin Brewer" Subject: Re: Bermuda 'quake Date: Thu, 3 Jul 1997 21:29:11 -0300 > From: Robert L Barns > I see nothing at or near 7/1 21:12 although my noise level was high for a > few hours around that time. Bob, Thanks for the response. How close would a M2.5 'quake have to be for you to see it (under normal circumstances)? regards, Martin _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: John Hernlund Subject: frequency, energy, and rupture length Date: Fri, 04 Jul 1997 21:30:49 -0700 (MST) I have a question for y'all. I was told once that the period of a seismic wave was approximately proportional to the rupture length of the event. In addition, it was inferred that the longer period quakes had a larger magnitude. I don't know a whole lot about this stuff yet and was wondering if anyone could elaborate on this for me. I know this much: The amount of energy released is proportional to the work done by the force on the system. Some of it is released as heat energy, and some as kinetic energy which it eventually transmits as various seismic waves due to the transfer of these kinetic displacements. As far as the forces go there is the tectonic or gravitational force that causes the initial stress, the force of static friction which is overcome by the stress, and then the kinetic friction as the displacement begins. A lot of energy can be released when this happens because the coefficient of static friction is always greater than the coefficient of kinetic friction. What I don't understand is: Why an increase in rupture length will cause a decrease in frequency. Is it because the movement will be impeded by the increased mass alongside the rupture therefore slowing the frequency? ****************************************************************************** John Hernlund E-mail: hernlund@....... WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson Subject: Re: frequency, energy, and rupture length Date: Sat, 05 Jul 1997 17:45:23 +1200 this is a new one on me, John, In the many books read over the years never come across a comment like that, have you any references, were the comments to you from a scientific source??? the surface waves of an event are the ones with the real long preiods BUT!!! you get very large deep events where the surface waves are virtually non-existant but you still have a large rupture area Dave At 09:30 PM 7/4/97 -0700, you wrote: >I have a question for y'all. I was told once that the period of a seismic >wave was approximately proportional to the rupture length of the event. >In addition, it was inferred that the longer period quakes had a larger >magnitude. I don't know a whole lot about this stuff yet and was >wondering if anyone could elaborate on this for me. >What I don't understand is: > Why an increase in rupture length will cause a >decrease in frequency. Is it because the movement will be impeded by >the increased mass alongside the rupture therefore slowing the frequency? > > John Hernlund > E-mail: hernlund@....... Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm Q-BIT'SLAWNo.9: INTERCHANGEABLEPARTS-WON'TBE Q-BIT'SLAWNo.10: ANY WIRING ERRORINANYCONSTRUCTIONWILLBEIN THE DIRECTION OF THE MOST DAMAGE Q-BIT'SLAWNo.13:IDENTICALPARTSAREN'T _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert L Barns <75612.2635@..............> Subject: Re: Bermuda 'quake Date: Sat, 5 Jul 1997 10:10:42 -0400 Martin, I est. that a 2.5 would have to be less than 15 miles for me to see it.= Bob Barns _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Charlie & Terri Thompson Subject: Quake detection distance Date: Sat, 05 Jul 1997 09:20:04 -0500 The two Texas quakes that have occurred this year were approx Mag 3.5 and I recorded them at a distance of about 200 miles. So a Mag 2.5 at 20 miles seems to scale correctly. I have a quake distance detection map on my web page. The data for the map was based on a Lehman seismometer. http://www.onr.com/user/ct/ct.html -Charlie Thompson At 10:10 AM 7/5/97 -0400, you wrote: >Martin, > I est. that a 2.5 would have to be less than 15 miles for me to see it. >Bob Barns > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > _ ________________________________________________ _ / ) | | ( \ / / | Charlie Thompson WB4HVD | \ \ _( (_ | _ e-mail: ct@....... _ | _) )_ (((\ \> |/ ) http://www.onr.com/user/ct/ct.html ( \| Charlie Thompson wrote: > Subject: Quake detection distance > Date: Saturday, July 05, 1997 11:20 AM > > The two Texas quakes that have occurred this year were approx Mag 3.5 > and I recorded them at a distance of about 200 miles. So a Mag 2.5 > at 20 miles seems to scale correctly on the same subject Bob Burns wrote > > I est. that a 2.5 would have to be less than 15 miles for me to see it. Thank you both for your comments. It looks as if my calibration is way out. Not surprising perhaps as the only confirmed 'quake I have detected is the Mag 6.6 event in the Aleutians on 17 June. Thanks Charlie for directing me to your web site, I shall visit with interest. Martin _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: John Hernlund Subject: linear response Date: Sat, 05 Jul 1997 23:00:12 -0700 (MST) I have been thinking ever since somebody posted here a while back on the best arrangement of a magnet-coil system. It seems for the most part that for small displacments in relation to the size of the coil and magnet that any non-linearity will be mostly negligible. I think this is one of the areas where large coil designs have an accuracy advantage when measuring larger displacements. Ideally, since the output is proportional to the cross product of the relative velocity and the magnetic field a single wire should be arranged so that it is both perpendicular to the direction of motion and the the magnetic field lines. But applying the correct geometry to a coil is a bit more involved. It seems like the best way is to have an arrangement like this: Use sets of flat long magnets that are magnetized thickwise, not lengthwise (one or more set depending). Set up some on the inside of a coil so that the south pole faces point outwards from the center of the circle thus formed. Orient these as close to the inside face of the coils as possible. Next, put matching pairs of magnets around the outside of the coil as close as possible to each one inside with the north poles facing inward toward in center of the circular coil. Now this would have to be oriented so that the magnets would be stationary and the coil moving along its symmetric axis, or vice versa. The theory for this is that the net magnetic flux for the cylinder walls will be more positive or negative, provided that the coil is not taller than the magnets. In this way, the field lines from the north poles of the inner magnets will be repulsed and tend toward the top and bottom of the coil. Is this correct? Has anyone else tried anything similar to this??? ****************************************************************************** John Hernlund E-mail: hernlund@....... WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jim Hannon Subject: Re: linear response Date: Sun, 06 Jul 1997 07:50:26 -0500 John Hernlund wrote: > > > > The theory for this is that the net magnetic flux for the cylinder > walls will be more positive or negative, provided that the coil is not > taller than the magnets. In this way, the field lines from the north > poles of the inner magnets will be repulsed and tend toward the top and > bottom of the coil. > > Magnetics was one of the more difficult subjects I had in school. It is so hard to visulize what those magnetic field lines are going to do. It seems that the coil and magnet arrangment for a hombuilt seismograph has at least these requirements. 1. A somewhat linear response to the velocity of the coil. 2. As much voltage output as possible. 3. Be relativly easy to make with materials that can be obtained inexpensively. Requirement number 3 seems to be at the heart of a lot of the struggling that goes into a design. One thing that seems to be common in the design of commercial electromagnetic devices is that they use a single magnet and provide a path from one pole of the magnetic to the other, for the magnetic flux with soft iron or some other permeable material. The coil is then placed in a small gap in this magnetic circuit. Magnetic flux being compared to electric current and any resistance to the flux, such as air in the path, causes the field in the gap to be weaker. Look at the magnetic design of a loudspeaker or the voice coil actuator in a computer hard drive. I think the magnets in a hard drive voice coil actuator would make a great seismograph. -- Jim Hannon http://soli.inav.net/~jmhannon/ 42,11.90N 91,39.26W _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Charlie & Terri Thompson Subject: Unidentified Event Date: Sun, 06 Jul 1997 10:13:57 -0500 Looks like USGS missed a small event at: 7/6/97 1:36 UTC (approx mag 4.8) about 1500 miles from Buda, Texas. This was probably Mexico or the Carribbean. Did anyone else record an event at or near this time? thanks, Charlie _ ________________________________________________ _ / ) | | ( \ / / | Charlie Thompson WB4HVD | \ \ _( (_ | _ e-mail: ct@....... _ | _) )_ (((\ \> |/ ) http://www.onr.com/user/ct/ct.html ( \| Subject: Re: linear response Date: Sun, 06 Jul 1997 07:30:28 -0700 Hi Jim & John Since I wrote to origninal note I tried a couple of coil/magnetic arrangements. The one that worked the best with the minimum # of parts was to orientate the coil pertendicular to the direction of motion and place a cylindrical magnet near ,but not inside, the coil. The flux lines are crossing the coil going from pole to pole. I think that the idea John suggested would be stronger; However, I have had problems in the past placing magnets next to each other that were oriented the same way. They tend to repel each other. I have also thought a hard drive coil would be great also. I would love to find a NG one somewhere to play with. But I think hard drives can also come with stepper motors. Any ideas as to which have stepper motors and which have voice coil? Barry Jim Hannon wrote: > Look at the > magnetic design of a loudspeaker or the voice coil actuator in a > computer hard drive. I think the magnets in a hard drive voice coil > actuator would make a great seismograph. > -- > Jim Hannon > http://soli.inav.net/~jmhannon/ > 42,11.90N 91,39.26W > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: roger baker Subject: Re: linear response Date: Sun, 6 Jul 1997 11:34:22 -0500 (CDT) Friends, The optimum requirements for a force balancing setup are distinctly different than those for detection of motion, least this might be an issue. Magnetic circuits weaken rapidly as any gap increases and this has caused loudspeakers to be designed the way they are with narrow circular gaps just wide enough to admit a light coil. But since the design has been optimized for low weight and high power its hard to get many turns into this gap for good voltage output. You can design the coil around the magnets or vice versa, but here you generally want lots of turns, so a pancake sort of coil has evolved to balance lots of turns with a modest magnet gap. Of course you could double the sensitivity by mountting a second magnet on the opposite side of the coil with the poles reversed. This might improve linearity if arranged so that when one half signal strengthens, the other attenuates. My suggestion however would be to take apart a geophone and remount the magnet and coil on a Lehman, but without the geo's spring of course. I offer this suggestion in light of the fact that geophones have been carefully engineered to do about exactly what you want to do in terms of generating voltage from small motions. You can all get ready to flame me for saying this, but my opinion is that coils may be obsolete as displacement transducers on the best long period instruments and may be replaced by optical and capacitative transducers that have as much sensitivity but are DC; they do not weaken in signal strength as velocity increases with long periods. From the time of Galitizen, magnetics has been favored because it was cheap and easy and sensitive and fit in with the technology of the day. Now things are different. Force feedback has different requirements and as a method of achieving the desired results, it is the only game in town. Since the displacement is miniscule, theoretically zero in fact, there are no magnetic non-linearities to fight and a coil attracts and repels equally with a reverse in voltage so long as nothing moves. I figure that so long as you have to have some mass, that mass might just as well be a ceramic magnet. I use a flat magnet and a flat coil made of fine wire wound with wire wet with a little epoxy so the coil holds its shape.The two are mounted facing each other with a narrow gap. --Yours, Roger Baker _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jim Hannon Subject: Re: linear response Date: Sun, 06 Jul 1997 12:12:14 -0500 barry lotz wrote: > But I think hard drives can also come with stepper motors. > Any ideas as to which have stepper motors and which have voice coil? > Barry > > message: leave PSN-L I don't know by brand and model but most of the newer ones have evolved to the voice coil arrangment. We get a lot of dead drives at work and sometimes the PC repair guy will let someone have the old drive to salvage. I haven't gotten any myself so I don't have any to play with. -- Jim Hannon http://soli.inav.net/~jmhannon/ 42,11.90N 91,39.26W _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: Re: linear response Date: Sun, 06 Jul 1997 11:47:11 -0700 Roger Even though my Lehman has given results to my satisfaction over the years, I agree and force balance has my attention right now. You mentioned they are DC, I assume you mean response wise since both types you mentioned require a AC excition signal. I am still using a coil as the restoring force. To get around the high frequencies produced by acceleration measurements I plan to integrate the digital signal mathematically ,in real time, to velocity. I think this could be accomplished by simply adding the readings in time. The readings would have to be adjusted to be centered around zero to avoid overflow. Barry >roger baker wrote: > > You can all get ready to flame me for saying this, but my opinion is that > coils may be obsolete as displacement transducers on the best long period > instruments and may be replaced by optical and capacitative transducers > that have as much sensitivity but are DC; they do not weaken in signal > strength as velocity increases with long periods. From the time of > Galitizen, magnetics has been favored because it was cheap and easy and > sensitive and fit in with the technology of the day. Now things are > different. > > Force feedback has different requirements and as a method of achieving > the desired results, it is the only game in town. Since the displacement > is miniscule, theoretically zero in fact, there are no magnetic > non-linearities to fight and a coil attracts and repels equally with > a reverse in voltage so long as nothing moves. I figure that so long as > you have to have some mass, that mass might just as well be a ceramic > magnet. I use a flat magnet and a flat coil made of fine wire wound with > wire wet with a little epoxy so the coil holds its shape.The two are > mounted facing each other with a narrow gap. > > --Yours, Roger Baker > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Al Allworth Subject: Re: linear response Date: Sun, 6 Jul 1997 12:49:23 -0700 At 07:50 AM 7/6/97 -0500, you wrote: >John Hernlund wrote: I think the magnets in a hard drive voice coil >actuator would make a great seismograph. >-- >Jim Hannon Hi Jim and all, I have saved the head drive assemblies from several hard drives but haven't put anything together yet. I think the parts from the 3 1/2 inch drives are all voice coil type. The stepping motors were too slow for modern computers. I have seen the inside of 2 1/2 inch drives used in laptop computers at trade shows and think they would be great for making a sensor. They use rare earth magnets that are so strong that one can't pull them off of a flat piece of iron by hand. New subject: Has any experience with the use of strain guages in making seismometers? They are true displacement devices and can be easily constructed. Cost is low also. I have designed them into electronic scales and felt they were quite stable. You connect them as a bridge so the thermal effects cancel. It's also possible to connect them so you can get two axis output. ____________________________________________________________________________ Al Allworth, Gold Beach, OR aallworth@........ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Ron Westfall Subject: Re: Unidentified Event Date: Sun, 06 Jul 1997 13:59:03 -0700 The NEIC is currently showing that an M4.8 occurred near the coast of Nicaragua (11.61N, 86.89W) at 1:36:39. That was probably it. Did anybody else see a large event around 10:00 UTC 07/06/97? I had what looked like surface waves coming in for an hour and a half. The NEIC is showing an M6.5 near the coast of Chile (29.99S, 71.68W) at 9:54:02. I wonder if that's it? This is my first experience seeing surface waves. Does anybody have a sense of how large a quake has to be at a given distance before you will pick up the surface waves? Ron Westfall westfall@...... Charlie & Terri Thompson wrote: > Looks like USGS missed a small event at: > > 7/6/97 1:36 UTC (approx mag 4.8) about 1500 miles > from Buda, Texas. > > This was probably Mexico or the Carribbean. > > Did anyone else record an event at or near this time? _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jean-Jacques HUNSINGER Subject: Re: Unidentified Event Date: Sun, 06 Jul 1997 23:57:19 +0200 Ron Westfall wrote: ...... > Did anybody else see a large event around 10:00 UTC 07/06/97? I had > what looked like surface waves coming in for an hour and a half. The > NEIC is showing an M6.5 near the coast of Chile (29.99S, 71.68W) at > 9:54:02. I wonder if that's it? > ..... Hi, I got this event here in France at 10h28 UTC Regards. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: Quake detection distance Date: Sun, 06 Jul 1997 16:10:20 -0600 Charlie- Very interesting map you have made. Station noise will be a limiting factor of recordings of local/regional events that are dominated by high frequencies. -Edward Charlie & Terri Thompson wrote: > > The two Texas quakes that have occurred this year were approx Mag 3.5 > and I recorded them at a distance of about 200 miles. So a Mag 2.5 > at 20 miles seems to scale correctly. I have a quake distance detection > map on my web page. The data for the map was based on a Lehman seismometer. > > http://www.onr.com/user/ct/ct.html > > -Charlie Thompson > > At 10:10 AM 7/5/97 -0400, you wrote: > >Martin, > > I est. that a 2.5 would have to be less than 15 miles for me to see it. > >Bob Barns > > > >_____________________________________________________________________ > > > >Public Seismic Network Mailing List (PSN-L) > > > >To leave this list email listserver@............. with the body of the > >message: leave PSN-L > > > > > > _ ________________________________________________ _ > / ) | | ( \ > / / | Charlie Thompson WB4HVD | \ \ > _( (_ | _ e-mail: ct@....... _ | _) )_ > (((\ \> |/ ) http://www.onr.com/user/ct/ct.html ( \| (\\\\ \_/ / Latitude 30.112 N \ \_/ ////) > \ / Longitude 97.891 W \ / > \ _/ Seismic Station .BUE \_ / > / / |________________________________________________| \ \ > / / \ \ > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Charlie & Terri Thompson Subject: Re: Quake detection distance Date: Sun, 06 Jul 1997 21:28:31 -0500 In-Reply-To: <33C017CC.E82@........> References: <3.0.1.16.19970705092004.2c974e84@.......> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" I can't take credit for the map...one of our PSN members in San Diego generated it for me based on his Lehman data and my Lat/Lon. It does however, correlate well with my Lehman data. -Charlie At 04:10 PM 7/6/97 -0600, you wrote: >Charlie- >Very interesting map you have made. Station noise will be a limiting >factor of recordings of local/regional events that are dominated by high >frequencies. >-Edward > >Charlie & Terri Thompson wrote: >> >> The two Texas quakes that have occurred this year were approx Mag 3.5 >> and I recorded them at a distance of about 200 miles. So a Mag 2.5 >> at 20 miles seems to scale correctly. I have a quake distance detection >> map on my web page. The data for the map was based on a Lehman seismometer. >> >> http://www.onr.com/user/ct/ct.html >> >> -Charlie Thompson >> >> At 10:10 AM 7/5/97 -0400, you wrote: >> >Martin, >> > I est. that a 2.5 would have to be less than 15 miles for me to see it. >> >Bob Barns >> > >> >_____________________________________________________________________ >> > >> >Public Seismic Network Mailing List (PSN-L) >> > >> >To leave this list email listserver@............. with the body of the >> >message: leave PSN-L >> > >> > >> >> _ ________________________________________________ _ >> / ) | | ( \ >> / / | Charlie Thompson WB4HVD | \ \ >> _( (_ | _ e-mail: ct@....... _ | _) )_ >> (((\ \> |/ ) http://www.onr.com/user/ct/ct.html ( \| > (\\\\ \_/ / Latitude 30.112 N \ \_/ ////) >> \ / Longitude 97.891 W \ / >> \ _/ Seismic Station .BUE \_ / >> / / |________________________________________________| \ \ >> / / \ \ >> >> _____________________________________________________________________ >> >> Public Seismic Network Mailing List (PSN-L) >> >> To leave this list email listserver@............. with the body of the >> message: leave PSN-L > >-- >Edward Cranswick Tel: 303-273-8609 >US Geological Survey, MS 966 Fax: 303-273-8600 >PO Box 25046, Federal Center cranswick@........ >Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > _ ________________________________________________ _ / ) | | ( \ / / | Charlie Thompson WB4HVD | \ \ _( (_ | _ e-mail: xctx@....... _ | _) )_ (((\ \> |/ ) http://www.onr.com/user/ct/ct.html ( \| Subject: Re: Quake detection distance Date: Sun, 06 Jul 1997 21:31:58 -0500 In-Reply-To: <33C017CC.E82@........> References: <3.0.1.16.19970705092004.2c974e84@.......> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Proper credit for the generation of the map should (I think) go to: Fred Bruenjes in San Diego. Thanks Fred! -Charlie At 04:10 PM 7/6/97 -0600, you wrote: >Charlie- >Very interesting map you have made. Station noise will be a limiting >factor of recordings of local/regional events that are dominated by high >frequencies. >-Edward > >Charlie & Terri Thompson wrote: >> >> The two Texas quakes that have occurred this year were approx Mag 3.5 >> and I recorded them at a distance of about 200 miles. So a Mag 2.5 >> at 20 miles seems to scale correctly. I have a quake distance detection >> map on my web page. The data for the map was based on a Lehman seismometer. >> >> http://www.onr.com/user/ct/ct.html >> >> -Charlie Thompson >> >> At 10:10 AM 7/5/97 -0400, you wrote: >> >Martin, >> > I est. that a 2.5 would have to be less than 15 miles for me to see it. >> >Bob Barns >> > >> >_____________________________________________________________________ >> > >> >Public Seismic Network Mailing List (PSN-L) >> > >> >To leave this list email listserver@............. with the body of the >> >message: leave PSN-L >> > >> > >> >> _ ________________________________________________ _ >> / ) | | ( \ >> / / | Charlie Thompson WB4HVD | \ \ >> _( (_ | _ e-mail: ct@....... _ | _) )_ >> (((\ \> |/ ) http://www.onr.com/user/ct/ct.html ( \| > (\\\\ \_/ / Latitude 30.112 N \ \_/ ////) >> \ / Longitude 97.891 W \ / >> \ _/ Seismic Station .BUE \_ / >> / / |________________________________________________| \ \ >> / / \ \ >> >> _____________________________________________________________________ >> >> Public Seismic Network Mailing List (PSN-L) >> >> To leave this list email listserver@............. with the body of the >> message: leave PSN-L > >-- >Edward Cranswick Tel: 303-273-8609 >US Geological Survey, MS 966 Fax: 303-273-8600 >PO Box 25046, Federal Center cranswick@........ >Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > _ ________________________________________________ _ / ) | | ( \ / / | Charlie Thompson WB4HVD | \ \ _( (_ | _ e-mail: xctx@....... _ | _) )_ (((\ \> |/ ) http://www.onr.com/user/ct/ct.html ( \| Proper credit for the generation of the map >should (I think) go to: > > Fred Bruenjes > >in San Diego. > >Thanks Fred! That's correct, and you're welcome! I just thought that some people might be interested in the story behind the map. See http://icse1.ucsd.edu/~mbruenje/seismo/data.html if you're interested. Also, I've been meaning to update the map - the one Charlie has (and the one on my web site) was based on only about 3 months of data. Now that my Lehman has been running for around 10 months, I have a much better idea of its' capabilities. To make a long story short, I think the circles on the maps need to be a wee bit farther out, since lately I have been getting quakes from outside the circles (most recently, last week's 5.3 in Hawaii). Below are some real numbers derived from my distance vs magnitude plot (see the web page above), which is based on observations of around 500 earthquakes. Of the 500 quakes I searched for in my recordings over a 10 month period, about 130 were actually detected. Magnitude: Distance: ---------- --------- 2.0 40 mi 2.5 110 mi 3.0 140 mi 3.5 200 mi 4.0 300 mi 4.5 700 mi 5.0 1,300 mi 5.5 2,500 mi 6.0 4,500 mi 6.5 10,000 mi 7.0+ Anywhere on Earth By 'distance' I mean the maximum distance at which the effects of the quake can be seen by a standard Lehman-style seismometer in the middle of a large city (in my case, San Diego). People in quieter locations, or with better equipment, can expect to do better. I have noticed that Karl Cunningham, who is a few miles east of me, has a lower background noise - his earthquake traces stand out more and look cleaner than mine. So he can probably do better than this table suggests. I have also noticed that you really need higher sample rates to get local quakes. I had been using 1 sample/second for a long time and recently upgraded to 5 samples/s and this has made an incredible difference in the reception of local quakes. Now I can actually see the P and S waves! Fred Bruenjes ------------------------------------------ Fred Bruenjes mbruenje@........ http://icse1.ucsd.edu/~mbruenje/index.html _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Norman Davis WB6SHI Subject: Norcal network and detection Date: Sun, 06 Jul 1997 06:53:45 Can anyone point me to the Norcal Network, The frequencies they are on and a means to detect the sites. I have done this a few years back on the single axis sites, but the one I can hear at my new location in Shingle Springs, Ca is a 3 axis site with 3 tones. Any one have a skematic on a decoder. Norman Davis WB6SHI Email normd@............. Shingle Springs, Ca, USA _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Mike Stickney Subject: Re: frequency, energy, and rupture length Date: Mon, 7 Jul 97 08:12:28 MDT At 09:30 PM 7/4/97 -0700, you wrote: >What I don't understand is: > Why an increase in rupture length will cause a >decrease in frequency. Is it because the movement will be impeded by >the increased mass alongside the rupture therefore slowing the frequency? > > >****************************************************************************** > > John Hernlund > E-mail: hernlund@....... > WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ > >****************************************************************************** Hi John: I haven't seen much response to your querry so I'll take a stab at it. Large earthquakes do generate lots of high frequency energy but they also generate low frequency energy not present in smaller quakes. Large quakes generate low frequencies because the long dimensions of the fault that slipped can radiate waves with long wavelengths. For distant large earthquakes, significant amounts of the high frequency energy has attenuated but most of the low frequency energy remains unattenuated and can be recorded by your seismograph. The lowest frequency generated by an earthquake is proportional to fault rupture dimensions. -Mike Stickney Montana Bureau of Mines and Geology Butte MT _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Charles R. Patton" Subject: Re: linear response Date: Mon, 07 Jul 1997 09:54:12 -0700 A few notes on disk drives (I work in the industry). 1) You can pretty much tell the stepper drives because the stepper motors were mounted on the outside at one end. The end of the shaft was outside and had a "flag" on it for an opto-interrupter in order to locate track zero. The disk motor had an external flywheel/drive magnets with a small inductive sense of a small hole drilled in the rim. The drive coils underneath that flywheel had hall effect sensors for position sense. (All my experience is with Western Digital drives, but most others are similar at the same time frame.) We quit manufacturing stepper drives about 7 or 8 years ago and went totally to voice coil designs. 2) Voice coil designs have nothing except the circuit board on the outside. (This is because they must be sealed against dust due to the low flying heights of the heads.) On 3 1/2 drive designs the actuator is a rotary design with the heads about 2" from the pivot and the center of the voice coil about 1" from the pivot. If you imagine the coil as a flat trapezoidal shaped (like a pie wedge) with the narrow end of the wedge pointing to the pivot point. This moves over the flat magnet which is poled with one area N and one area S. The coil moves close over the surface of this magnet. Then on top of this is placed a 'keeper' or 'flux return plate' which returns the flux to the other side of the magnet. Some designs use two magnets or even four for very powerful (read fast access times) accelerations. One of the key design points is maintain the field evenly over the stroke. Uneven fields affects the ability of the control system. So as for some stakes in the ground: This field uniformity is in the 10% range and a typical BEMF would be 40mV per inch per second of the coil movement. |------------------------------------| |--------- upper flux plate----------| |------------------------------------| |--| |--| |--| |XXX| |***| |--| |--| |XXX| coil |***| |--| Sliced |--| ^ | |--| End View of coil in field |--| | field | |--| Along With Flux Plates |--| |N vS |--| (Coil moves side-to-side |--| |**************************| |--| this illustration.) |--| |********magnet************| |--| |------------------------------------| |------- lower flux plate -----------| |------------------------------------| Charles R. Patton patton@......... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jim Hannon Subject: Re: Quake detection distance Date: Mon, 07 Jul 1997 17:24:44 -0500 This map really makes it easy to visulize the quake distances. It looks a lot like a satellite visability map. One thing that I think would be a useful addition is showing the shadow zone for the P waves on the same map. -- Jim Hannon http://soli.inav.net/~jmhannon/ 42,11.90N 91,39.26W _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: frequency, energy, and rupture length Date: Mon, 07 Jul 1997 21:13:19 -0600 John- With respect to why the dominant period of the source ground motions generated by an earthquake is proportional to the rupture length, consider the fault as an antenna that radiates seismic waves. Imagine the fault to be divided into a set of segments that are some fraction of the total fault length. In general, wavelengths equal to these segment lengths will tend to destructively interfere with each other at some distance from the fault, and their sum will be less than the contribution of one segment times the number of segments. For wavelengths similar to the total fault length, the fault will appear to be a single coherent radiator and there will be no destructive interference at that period, which will thus appear to be a maximum. Jim Brune has written the classic paper on the subject: Brune, J.N. (1970). Tectonic stress and the spectra of seismic shear waves from earthquakes, J. Geophys. Res., v. 75, pp. 4997-5009. -Edward John Hernlund wrote: > > I have a question for y'all. I was told once that the period of a seismic > wave was approximately proportional to the rupture length of the event. > In addition, it was inferred that the longer period quakes had a larger > magnitude. I don't know a whole lot about this stuff yet and was > wondering if anyone could elaborate on this for me. > > I know this much: > The amount of energy released is proportional to the work done by the > force on the system. Some of it is released as heat energy, and some as > kinetic energy which it eventually transmits as various seismic waves due > to the transfer of these kinetic displacements. As far as the forces go > there is the tectonic or gravitational force that causes the initial > stress, the force of static friction which is overcome by the stress, and > then the kinetic friction as the displacement begins. A lot of energy > can be released when this happens because the coefficient of static > friction is always greater than the coefficient of kinetic friction. > > What I don't understand is: > Why an increase in rupture length will cause a > decrease in frequency. Is it because the movement will be impeded by > the increased mass alongside the rupture therefore slowing the frequency? > > ****************************************************************************** > > John Hernlund > E-mail: hernlund@....... > WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ > > ****************************************************************************** > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Re: Norcal network and detection Date: Mon, 07 Jul 1997 21:31:17 -0700 At 06:53 AM 7/6/97, Norman wrote: > Can anyone point me to the Norcal Network, The frequencies they are on and >a means to detect the sites. Unfortunately the frequencies and tone channels are not on the Net that I know of. This info is kept in a book in the basement of the local (Menlo Park) USGS office. They are VERY reluctant to give out this info because they are afraid of people stilling their equipment. BUT the latitude and longitude of the stations are on the Web at http://quake.geo.berkeley.edu/ncedc/station.info.html, so go figure.... The lat/long info is down to 4 decimal points (a few feet?) so anyone with a GPS receiver could find them. There are several ways to figure out the station you are receiving. You can go over to the Menlo Park USGS office and see if they will tell you the info. If you have a RF frequency and tell them you are with the PSN they might tell you what tone as what. Most of the channels are short period high gain vertical sensors. But they do have some short period horizontal and other types of sensors around. Also, a RF link may be a repeater for other stations sensor. You can figure out the location of the sensors two other ways. Both use known locations of events. By using the P and S wave distance you can plot on a map several known local events. This way you should be able to figure out the location, but, reading the P and S waves takes some practice. The other way requires that you have accurate timing, down to about 10 ms. At the Berkeley.edu site you can get the P arrival times for local events. By looking at the list of arrival times for each station you should be able to fine one that matches the unknown station. >I have done this a few years back on the >single axis sites, but the one I can hear at my new location in Shingle >Springs, Ca is a 3 axis site with 3 tones. Any one have a skematic on a >decoder. I sell a demodulator card that can be used to receive the info (see http://psn.quake.net/telebrd.html). The advantage of my card is it can receive any one of the 8 tones, used by the USGS, by simple setting a dip switch on the board. The card connects up to the audio output of a police scanner (or other receiver) and produces a +- 5 volt signal than can then go into a A/D card or chart recorder. Hope this helps... -Larry Cochrane _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: mbruenje@........ (Fred Bruenjes) Subject: Re: Quake detection distance Date: Tue, 08 Jul 1997 00:04:07 -0700 >One thing that I think would be >a useful addition is showing the shadow zone for the P waves on the same >map. Excellent suggestion. I've now redrawn the map, with my new data, and with the P wave shadow zone. It's kind of neat to be able to see just which areas this covers. I also made up several versions of the map, each for a different place around the world, so everybody can get an idea of what it looks like at their location. The URL again, in case anyone missed it: http://icse1.ucsd.edu/~mbruenje/seismo/data.html The new maps are about halfway down the page. Fred ------------------------------------------ Fred Bruenjes mbruenje@........ http://icse1.ucsd.edu/~mbruenje/index.html _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Martin Brewer" Subject: Building a Rigid Seismometer Date: Tue, 8 Jul 1997 19:57:30 -0300 Hi everyone, Now that the Bermuda N-S, home-built Lehman instrument seems to be working, I am about to start building its E-W sibling. Being cramped for useable space, my idea is to build a tripod around the N-S instrument and place an E-W oriented sensor on a raised platform above the N-S instrument. I need some advice on the engineering so that the structure is rigid enough not to have unwanted resonance and can track 'quakes accurately. I am thinking of building a tripod about 4 feet high to support the base of the sensor. Can I use galvanized pipe (given that it will be built around the N-S ground level sensor)? Could I use concrete pillars? If so what diameter should they be? Can the pillars be reinforced by ordinary galvanized re-bar without affecting the N-S instrument which will have magnet and coil within, say, a foot of the nearest pillars? Does anyone have any working designs for instruments built four feet (plus or minus) above the ground? One last question. Does such an elevated support need to be bolted to the ground? From earlier correspondence on the PSN, I conclude that it is totally unnecessary. My "Doubting Thomas" of a brother-I- law (who is the nuts and bolts man on this project) thinks differently. I would be grateful for any and all comments. Regards, Martin _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Martin Brewer" Subject: Surface Waves Date: Tue, 8 Jul 1997 22:27:09 -0300 Bermuda has picked up two sets of waves 13 minutes apart. I thought it might be some major event in the Aleutians but no follow through. In any case the waves are long period. Has anyone picked up the event(s): Long waves in two separate packets at 01:23 UTC and 01:36 UTC arrival times at Bermuda? Regards, Martin _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Charlie & Terri Thompson Subject: Re: Surface Waves Date: Tue, 08 Jul 1997 23:17:53 -0500 Martin, Dr.John Lahr's wave arrival time prediction web page can help you identify the Bermuda arrival times of various waves..try the following URL: http://www.giseis.alaska.edu/Input/lahr/artim.html Operation is reasonably self-explanatory. A wonderful tool! -Charlie At 10:27 PM 7/8/97 -0300, you wrote: >Bermuda has picked up two sets of waves 13 minutes apart. I thought it >might be some major event in the Aleutians but no follow through. In any >case the waves are long period. Has anyone picked up the event(s): Long >waves in two separate packets at 01:23 UTC and 01:36 UTC arrival times at >Bermuda? >Regards, >Martin > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > _ ________________________________________________ _ / ) | | ( \ / / | Charlie Thompson WB4HVD | \ \ _( (_ | _ e-mail: xctx@....... _ | _) )_ (((\ \> |/ ) http://www.onr.com/user/ct/ct.html ( \| Subject: Re: Building a Rigid Seismometer Date: Wed, 09 Jul 1997 10:14:25 -0600 Content-Transfer-Encoding: 7bit Martin- I think it is an EXTREMELY BAD idea to place the seismometer on any kind of platform above the ground. The structure of the platform will tend to produce amplifications and resonances that will significantly compound the complexities that already exist from site response and instrument response. So avoid it if you can. -Edward Martin Brewer wrote: > > Hi everyone, > > Now that the Bermuda N-S, home-built Lehman instrument seems to be working, > I am about to start building its E-W sibling. Being cramped for useable > space, my idea is to build a tripod around the N-S instrument and place an > E-W oriented sensor on a raised platform above the N-S instrument. > > I need some advice on the engineering so that the structure is rigid enough > not to have unwanted resonance and can track 'quakes accurately. > > I am thinking of building a tripod about 4 feet high to support the base of > the sensor. Can I use galvanized pipe (given that it will be built around > the N-S ground level sensor)? Could I use concrete pillars? If so what > diameter should they be? Can the pillars be reinforced by ordinary > galvanized re-bar without affecting the N-S instrument which will have > magnet and coil within, say, a foot of the nearest pillars? > > Does anyone have any working designs for instruments built four feet (plus > or minus) above the ground? > > One last question. Does such an elevated support need to be bolted to the > ground? From earlier correspondence on the PSN, I conclude that it is > totally unnecessary. My "Doubting Thomas" of a brother-I- law (who is the > nuts and bolts man on this project) thinks differently. > > I would be grateful for any and all comments. > > Regards, > Martin > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert L Barns <75612.2635@..............> Subject: Surface Waves Date: Wed, 9 Jul 1997 15:07:58 -0400 Martin, I looked in my DSR files for 7/4-7/8 (today at 18:00 UTC) and see nothi= ng around 1:30 for any of these days. I checked them all since you did not state a date. Bob Barns = _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert L Barns <75612.2635@..............> Subject: Quake detection dist. Date: Wed, 9 Jul 1997 15:07:53 -0400 Hi gang, The info at Charlie's page (www.onr.com/user/ct/ct.html) is very interesting esp. the photos and drawing of his Lehman. The use of Dexion= is a good idea. = The several messages discussing 'quake detection distance ignores an important factor. A vertical seismometer is omnidirectional and this factor is irrelevant. However, most of us use horizontal (e.g., Lehman &= S-G) seismometers. They have a bi-directional response. Ground motion perpendicular to the boom will give a maximum output but motion along the= boom will produce zero output (at least in theory). = The output should be close to proportional to the cosine of the angle between the incoming wave and the boom. This factor is also ignored in SDR and WINQUAKE which uses only the distance and an empirical factor to estimate the magnitude. = Also, it would be handy if WINQUAKE showed the azimuth the quake a= s well as the azi the 'quake. The azi to the quake, combined with t= he orientation of the seismometer could be used to correct the est. of magnitude. Bob Barns = _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Nick & Sophie Caporossi Subject: Homebrew Lehman Date: Wed, 09 Jul 97 17:24:57 -0500 -- [ From: Nick & Sophie Caporossi * EMC.Ver #2.5.02 ] -- Hi Charlie Thompson: You have a interesting Homepage. The jpgs of your homebrew seismometer give a pretty good idea of your setup. A few dimensions of your set up would be even more help. I would like to know the distance between the Copper Damper plate and the pickup coil. Do have any trouble keeping the Bolt end ( that is ground sharp) in place with the horizontal threaded rod? Some of the other sites on your Homepage are also interesting. Nick Caporossi nickcap@............. 40, 24.757N 74, 23.435W _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Walter Williams" Subject: GeoPhone? Date: Wed, 9 Jul 1997 16:08:01 +0000 Hello All, Ok. I am a rank newbie. I have read several of the archives for this year and I have clicked and clacked around the various PSN personal pages and now I have a question or two. What is a geophone?, and how is it useful for instrumenting seismic activity? I have seen several people's implementations of 'Lehman' seismometers and I was wondering if maybe an all digital (well almost) instrument is feasible? Some blend of optical/ccd and DSP without all the attendant analog filter circuits, maybe? Best Regards, Walt Williams, 97.07.09 SIS Woodland Hills, California, USA dfheli@.............. Checkout web page I helped make: http://mars.sgi.com/rovercom/rovcom.html _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson Subject: Re: Building a Rigid Seismometer Date: Thu, 10 Jul 1997 13:15:32 +1200 Ed, I agree totally, I sent Martin a personal message a few days ago also stating the resonance problems etc thanks for the professional backup Dave At 10:14 AM 7/9/97 -0600, you wrote: > >Content-Transfer-Encoding: 7bit > >Martin- > I think it is an EXTREMELY BAD idea to place the seismometer on any >kind of platform above the ground. The structure of the platform will >tend to produce amplifications and resonances that will significantly >compound the complexities that already exist from site response and >instrument response. So avoid it if you can. >-Edward > >Martin Brewer wrote: >> >> Hi everyone, >> >> Now that the Bermuda N-S, home-built Lehman instrument seems to be working, >> I am about to start building its E-W sibling. Being cramped for useable >> space, my idea is to build a tripod around the N-S instrument and place an >> E-W oriented sensor on a raised platform above the N-S instrument. >> >> I need some advice on the engineering so that the structure is rigid enough >> not to have unwanted resonance and can track 'quakes accurately. >> >> I am thinking of building a tripod about 4 feet high to support the base of >> the sensor. Can I use galvanized pipe (given that it will be built around >> the N-S ground level sensor)? Could I use concrete pillars? If so what >> diameter should they be? Can the pillars be reinforced by ordinary >> galvanized re-bar without affecting the N-S instrument which will have >> magnet and coil within, say, a foot of the nearest pillars? >> >> Does anyone have any working designs for instruments built four feet (plus >> or minus) above the ground? >> >> One last question. Does such an elevated support need to be bolted to the >> ground? From earlier correspondence on the PSN, I conclude that it is >> totally unnecessary. My "Doubting Thomas" of a brother-I- law (who is the >> nuts and bolts man on this project) thinks differently. >> >> I would be grateful for any and all comments. >> >> Regards, >> Martin >> >> _____________________________________________________________________ >> >> Public Seismic Network Mailing List (PSN-L) >> >> To leave this list email listserver@............. with the body of the >> message: leave PSN-L > >-- >Edward Cranswick Tel: 303-273-8609 >US Geological Survey, MS 966 Fax: 303-273-8600 >PO Box 25046, Federal Center cranswick@........ >Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm Q-BIT'SLAWNo.9: INTERCHANGEABLEPARTS-WON'TBE Q-BIT'SLAWNo.10: ANY WIRING ERRORINANYCONSTRUCTIONWILLBEIN THE DIRECTION OF THE MOST DAMAGE Q-BIT'SLAWNo.13:IDENTICALPARTSAREN'T _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson Subject: big event Date: Thu, 10 Jul 1997 13:24:53 +1200 Martin, you must have got a great record of the Ms6.8, Mw6.9 from nthrn coast of Venezuela "just down the road from you". the Univ. of Reno Helicorder shows a great trace ( www address near bottom of my quakes page) Dave Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm Q-BIT'SLAWNo.9: INTERCHANGEABLEPARTS-WON'TBE Q-BIT'SLAWNo.10: ANY WIRING ERRORINANYCONSTRUCTIONWILLBEIN THE DIRECTION OF THE MOST DAMAGE Q-BIT'SLAWNo.13:IDENTICALPARTSAREN'T _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson Subject: Re: GeoPhone? Date: Thu, 10 Jul 1997 13:33:54 +1200 hello Walt, welcome to the group, a geophone is a very small and compact seismometer they are designed for the exploration industry but work very well for general seismic recording see http://www.geospacecorp.com/lg11d.jpg for a pic. of one that I use here in New Zealand dave At 04:08 PM 7/9/97 +0000, you wrote: >Hello All, > >Ok. I am a rank newbie. > >I have read several of the archives for this year and I have clicked >and clacked around the various PSN personal pages and now I have >a question or two. > >What is a geophone?, and how is it useful for instrumenting seismic >activity? > >I have seen several people's implementations of 'Lehman' seismometers >and I was wondering if maybe an all digital (well almost) instrument >is feasible? Some blend of optical/ccd and DSP without all the >attendant analog filter circuits, maybe? > >Best Regards, > >Walt Williams, 97.07.09 >SIS >Woodland Hills, California, >USA >dfheli@.............. > >Checkout web page I helped make: >http://mars.sgi.com/rovercom/rovcom.html > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm Q-BIT'SLAWNo.9: INTERCHANGEABLEPARTS-WON'TBE Q-BIT'SLAWNo.10: ANY WIRING ERRORINANYCONSTRUCTIONWILLBEIN THE DIRECTION OF THE MOST DAMAGE Q-BIT'SLAWNo.13:IDENTICALPARTSAREN'T _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Martin Brewer" Subject: Re: big event Date: Wed, 9 Jul 1997 21:54:17 -0300 David A Nelson wrote > Subject: big event > Date: Wednesday, July 09, 1997 10:24 PM > > Martin, you must have got a great record of the Ms6.8, Mw6.9 from > nthrn coast of Venezuela "just down the road from you". I certainly did Dave. I am posting it to the PSN event address in case anyone would like to see it. The recorded amplitudes are ten times larger than the best recorded here so far. The focus being directly south of Bermuda the N-S Lehman is in optimal orientation to record the S waves. I think I shall have the trace colourised and framed :o) Regards, Martin _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Martin Brewer" Subject: Re: Building a Rigid Seismometer Date: Wed, 9 Jul 1997 22:19:12 -0300 > Edward Cranswick wrote > Subject: Re: Building a Rigid Seismometer >July 09, 1997 1:14 PM > > Martin- > I think it is an EXTREMELY BAD idea to place the seismometer on any > kind of platform above the ground. Edward, Thank you for your advice. As you know Dave Nelson also pointed out the resonance problems. As a result of your's and David's comments, I think it is likely that I shall either find a convenient space in the basement (given the potential problems, more spaces are appearing convenient all the time!) or build a concrete slab outside. I have one of Larry's three-channel filter/amplifier boards as I had always intended to build a three axis system. The problem, as I understand it, is that I cannot afford to have more than about six feet of phono cable between the pickup coil and the amplifier. Am I right? or can I get away with say 12 feet? Of course I could buy another filter/amp board from Larry but I would rather not have to spend more than necessary :o) regards, Martin _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Martin Brewer" Subject: Re: Surface Waves Date: Wed, 9 Jul 1997 22:31:57 -0300 Martin, I looked in my DSR files for 7/4-7/8 (today at 18:00 UTC) and see nothing around 1:30 for any of these days. I checked them all since you did not state a date. Bob Barns Sorry Bob, The trace came through on 8 June, minutes before I e-mailed you. I must learn to be more explicit. What sort of recording did you get for today's Venezuela event [19:24 UTC, 9 July 1997, Lat 10.43N, Long 63.49W, Mag 6.8 - USGS NEIC data]? Regards, Martin _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Martin Brewer" Subject: Re: Homebrew Lehman Date: Wed, 9 Jul 1997 22:49:32 -0300 ---------- > Nick & Sophie Caporossi wrote about > Homebrew Lehman > Date: Wednesday, July 09, 1997 7:24 PM to > Charlie Thompson: > > Do have any trouble keeping the Bolt end ( that is ground sharp) in place > with the horizontal threaded rod? I had the same question when I started to build my Lehman. What I did was to find the balance point of the boom assembly - with all weights, magnet and damping mechanism in place - when it was suspended vertically from it's suspension wire. When the support wire is attached to the boom (via a washer with a small hole drilled near its edge) at the balance point determined by test hanging it as described, there is no tendency for the knife-edge at the other end of the boom to slip down or up from its position against the support system. I achieved this balance by splitting the weight. I have two three pound lead weights. One of them is on the knife-edge side of the magnet and its counterbalancing weight, the other is on the other side. I think on my next attempt I shall reduce the weight of the distant boom weight so that I can move it closer to the inner weight. On my assembly the weights are about 8 inches apart. I worry that some arcane compound pendulum effect may produce unwanted resonance. Comments greatly appreciated. regards, Martin _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson Subject: Venezuela quake Date: Thu, 10 Jul 1997 19:57:21 +1200 Martin, what an excellent record WELL DONE Dave Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm Q-BIT'SLAWNo.9: INTERCHANGEABLEPARTS-WON'TBE Q-BIT'SLAWNo.10: ANY WIRING ERRORINANYCONSTRUCTIONWILLBEIN THE DIRECTION OF THE MOST DAMAGE Q-BIT'SLAWNo.13:IDENTICALPARTSAREN'T _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Re: GeoPhone? Date: Thu, 10 Jul 1997 00:42:33 -0700 At 01:33 PM 7/10/97 +1200, David Nelson wrote: >hello Walt, > welcome to the group, a geophone is a very small and >compact seismometer they are designed for the exploration industry but work >very well for general seismic recording > I'm not sure about that... Short period sensors, like geophones, are fine for local and larger regional events but are not good for teleseismic events. Short period velocity sensors just can't pickup, or resolve, the low frequency waves from distant events. I think a Lehman (or modified SG sensors), is a little more "general purpose" do to its broader frequency range. A Lehman, with a period over 10 seconds, can be used for both local and teleseismic events. The SG sensor (see http://psn.quake.net/sgsensor.html) design can be modified to recording local events better by taking a signal out of the sensors before the integrator. This creates a signal that has more high frequency information and is better for viewing local events. Since Walt lives in So. California he can us a geophone and receive lots of events, but someone not so "lucky" to live in an EQ area will need something like a Lehman or SG sensors to pickup teleseismic events. Just my .02 cents... -Larry Cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Re: Building a Rigid Seismometer Date: Thu, 10 Jul 1997 00:57:19 -0700 At 10:19 PM 7/9/97 -0300, Martin Brewer wrote: >Edward, >Thank you for your advice. As you know Dave Nelson also pointed out the >resonance problems. As a result of your's and David's comments, I think it >is likely that I shall either find a convenient space in the basement >(given the potential problems, more spaces are appearing convenient all the >time!) or build a concrete slab outside. I have one of Larry's >three-channel filter/amplifier boards as I had always intended to build a >three axis system. The problem, as I understand it, is that I cannot afford >to have more than about six feet of phono cable between the pickup coil >and the amplifier. Am I right? or can I get away with say 12 feet? Of >course I could buy another filter/amp board from Larry but I would rather >not have to spend more than necessary :o) >regards, The problem is your are dealing with low levels of signal and the high impedance of the pickup coil. 12 to 15 feet of good shielded audio or RF cable should be fine. The thing to do is try it and see how much extra noise you get with the added cable. What you can do is see how much background noise (Min/Max A/D counts) you get with the pickup coil connected to the amp card with a small amount of cable. Then add the extra cable and see if the noise goes up much. This test should be done without the coil near a magnet. Hope this helps. Larry Cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Martin Brewer" Subject: Re: Building a Rigid Seismometer Date: Thu, 10 Jul 1997 06:49:21 -0300 ---------- > From: Larry Cochrane > > The problem is your are dealing with low levels of signal and the high > impedance of the pickup coil. 12 to 15 feet of good shielded audio or RF > cable should be fine. The thing to do is try it and see how much extra > noise you get with the added cable. What you can do is see how much > background noise (Min/Max A/D counts) you get with the pickup coil > connected to the amp card with a small amount of cable. Then add the extra > cable and see if the noise goes up much. This test should be done without > the coil near a magnet. Thank you Larry for your good advice. I shall experiment as you suggest. Martin _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Martin Brewer" Subject: Re: Venezuela quake Date: Thu, 10 Jul 1997 06:54:53 -0300 ---------- > From: David A Nelson > To: psn-l@............. > Subject: Venezuela quake > Date: Thursday, July 10, 1997 4:57 AM > > Martin, > what an excellent record WELL DONE > > Dave > Dave A. Nelson Thank you Dave, I'm still a bit awestruck that a home made device like mine can do such a good job. Of course it would be nothing without Larry's excellent electronics. Even so it is very pleasing. Martin _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert L Barns <75612.2635@..............> Subject: Re: Homebrew Lehman Date: Thu, 10 Jul 1997 10:48:30 -0400 Martin, The common use for a Lehman is for teleseismic events. This means that= frequencies less than 0.1 Hz are the only ones of primary concern. I thi= nk that it is impossible to get boom or suspension resonances at these low frequencies even if you tried. Bob Barns _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert L Barns <75612.2635@..............> Subject: Re: Surface Waves Date: Thu, 10 Jul 1997 10:48:26 -0400 Martin, Venezuela emitted a beauty! Should we send a thank-you note? Probably= not--I doubt that the government caused it. I got 20,000 counts p-p, 112,000 nm/sec with a signal/noise ratio of 100. P, S & SS obvious. With my P & S pics, I got org. of 19:24:31 and dis= t. 2154 mi. My clock was 2" fast. I wonder where the other 18 secs. went. I also saw what may be 2 aftershocks. One near 21:55:35 (1400 counts p-p) and one near 24:4:32 (700 counts). The tail of the main 19:24:11 shock was still vis. but these were above the level of the tail. Take a look for these. Bob Barns _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Doug Crice Subject: Re: Surface Waves Date: Thu, 10 Jul 1997 08:31:21 -0700 The morning news mentioned that a massive rescue effort is underway in Venezuela. A multi-story building collapsed and they reported 40 are believed dead. As with all earthquake reports from under-developed countries, the casualty count will probably increase as more news filters out. There were no pictures in the report, and the story was followed immediately with pictures from Mars. I was struck by the fact that we could get pictures from Mars but not from Venezuela. Doug Crice _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: JIM CRISTIANO Subject: Re: cables Date: Thu, 10 Jul 1997 09:13:09 -0700 Larry Cochrane wrote: > The problem is your are dealing with low levels of signal and the high > impedance of the pickup coil. 12 to 15 feet of good shielded audio or RF > cable should be fine. The thing to do is try it and see how much extra > noise you get with the added cable. What you can do is see how much > background noise (Min/Max A/D counts) you get with the pickup coil > connected to the amp card with a small amount of cable. Then add the extra > cable and see if the noise goes up much. This test should be done without > the coil near a magnet. > > Hope this helps. > et al, This is a good case for the afore mentioned suggestions of using a differential input amplifier configuration on the coil input and a 4-20mA current loop for the output. A current to voltage converter ( easier than it sounds) would interface to the A to D. Burr-Brown has a hot new 4-20mA IC called a XTR105 along with other current transmitter IC'S at burr-brown.com. If you're going remote, Linx tech. in Medford, Or. sells very small single-in-line package data radio transmitters and receiver boards that work at up to 800'. I found a way to get a linear, high sensitivity output from a 25mV/gauss MicroSwitch Linear Hall Effect Device. The problem is that the output is dc and getting the #*$?@~! magnet centered to the LOHET face for zero is impossible. So now I'm trying to use it in a vertical force-balanced sensor so that it will auto-zero itself. Regards, Jim cristiano@........... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Dennis Leatart Subject: VENEZUELA QUAKE Date: Thu, 10 Jul 1997 12:25:10 -0700 I also got a good trace of the Venezuela event-- 3 hours of data and over 56,000 data points. I also am seeing what looks like some aftershocks and surface waves. I have this on a *.bmp file if anyone is interested, I'll send you a copy? -- _____ __ | \.-----.-----.-----.|__|.-----. | -- | -__| | || ||__ --| |_____/|_____|__|__|__|__||__||_____| _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Walter Williams" Subject: Seismic Abstract Date: Thu, 10 Jul 1997 16:10:14 +0000 Hello All, In my studies I ran across this interesting abstract which may be of interest to some of you, please reference: http://www.agu.org/pubs/abs/jb/96JB01905/96JB01905.html Cheers, Walt Williams, 97.07.10 Woodland Hills, California, USA dfheli@.............. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Martin Brewer" Subject: Re: Homebrew Lehman Date: Thu, 10 Jul 1997 19:09:55 -0300 From: Robert L Barns Subject: Re: Homebrew Lehman Date: Thursday, July 10, 1997 11:48 AM Martin, The common use for a Lehman is for teleseismic events. This means that frequencies less than 0.1 Hz are the only ones of primary concern. I think that it is impossible to get boom or suspension resonances at these low frequencies even if you tried. Bob Barns Hi Bob, Thanks for the comforting words. But I'd seem to have seen some relatively high frequency stuff at about 0.3Hz in some events which I took to be P wave arrivals. Am I wrong? Regards, Martin _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Rex Klopfenstein, Jr." Subject: Re: Transmitting signal Date: Thu, 10 Jul 1997 19:22:16 -0400 ---------- > From: Martin Brewer > To: PSN-L Mailing List > Subject: Re: Building a Rigid Seismometer > Date: Wednesday, July 09, 1997 9:19 PM > > > The problem, as I understand it, is that I cannot afford > to have more than about six feet of phono cable between the pickup coil > and the amplifier. Am I right? or can I get away with say 12 feet? You might look at using 4-20mA current loops. There are ic's manufactured by Burr-Brown and others that convert voltage signals into 4-20mA tracking current loops. There are also ic's that convert the 4-20mA back to voltage _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Martin Brewer" Subject: Re: Surface Waves Date: Thu, 10 Jul 1997 19:29:34 -0300 From: Robert L Barns Subject: Re: Surface Waves Date: Thursday, July 10, 1997 11:48 AM Martin, Venezuela emitted a beauty! Hi Bob, She sure did. I didn't know seismic waves got that big!! I've been looking for anything that pokes it's head out of the 'ground noise. Obviously I have to set my sights higher. On that note, I have thought that I have been seeing some rumblings from the Montserrat volcano. have you been recording any long duration twice background microseismic activity of late especially on 25 June? With my P & S pics, I got org. of 19:24:31 and dist. 2154 mi. My clock was 2" fast. I wonder where the other 18 secs. went. Well two seconds of that is probably from my clock which could have been as much as 2 seconds slow. My origin time of 19:24:23 is still is still 12 seconds ahead of USGS's origin time of 09:24:11. I note on my trace that, depending on the Y-scale being used, the P wave pick can change. Two seconds before the main - relatively constant amplitude - P arrivals, there is a short train of lower amplitude waves that are still well above background. You may want to have a look at the initial P wave train at higher "magnification" I also saw what may be 2 aftershocks. One near 21:55:35 (1400 counts p-p) and one near 24:4:32 (700 counts). The tail of the main 19:24:11 shock was still vis. but these were above the level of the tail. Take a look for these. Bob Barns I looked for the reported aftershock of Mag 4.4 that USGS reported at 20:06 but of course that was completely swamped. I shall have look and see if I can see the aftershocks you indicate. Thanks for the challenge :o) Regards, Martin _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Martin Brewer" Subject: Re: Transmitting signal Date: Thu, 10 Jul 1997 19:48:11 -0300 ---------- > From: Rex Klopfenstein, Jr. > Subject: Re: Transmitting signal > Date: Thursday, July 10, 1997 8:22 PM > > > > ---------- > > From: Martin Brewer > > To: PSN-L Mailing List > > Subject: Re: Building a Rigid Seismometer > > Date: Wednesday, July 09, 1997 9:19 PM > > > > > > The problem, as I understand it, is that I cannot afford > > to have more than about six feet of phono cable between the pickup coil > > and the amplifier. Am I right? or can I get away with say 12 feet? > > You might look at using 4-20mA current loops. There are ic's manufactured > by Burr-Brown and others that convert voltage signals into 4-20mA tracking > current loops. There are also ic's that convert the 4-20mA back to voltage > Hi Rex, Thank you for your suggestion. I might have to set the second sensor in a more remote location than I would like to, in which case I might want to learn more about the solution you suggest. I am relatively ignorant in this area and will need some help if it gets to that stage. Regards, Martin _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Walter Williams" Subject: Meteor & Seismic Detectors Date: Thu, 10 Jul 1997 17:08:06 +0000 Hello All, I stumbled onto this "seismic instrument" while doing my search for low frequency anomaly detectors. Probably a very simple instrument? See: http://www.nitehawk.com/rasmit/jml0.html "EARTHQUAKE GROUND VELOCITY SENSOR Radio Astronomy Supplies is pleased to offer the FRANKLIN Ground Velocity Sensor. This system is the first portable and user friendly instrument ever produced, for recording earthquake and ground motion signals. You can record and view signals hundreds of times smaller than can be felt! This plug and go system simply attaches to your computer's serial port. Windows or DOS software included (please specify). " Cheers, Walt Williams, 97.07.10 Woodland Hills, California, USA dfheli@.............. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson Subject: Re: venezuela Date: Fri, 11 Jul 1997 12:40:16 +1200 Doug, the pic from venezuela show major damage...... so far 56 confirmed dead more expexted hospitals flooded with casulties people calling , from within the rubble, to rescuers using cellphones. Dave At 08:31 AM 7/10/97 -0700, you wrote: >The morning news mentioned that a massive rescue effort is underway in >Venezuela. A multi-story building collapsed and they reported 40 are >believed dead. As with all earthquake reports from under-developed >countries, the casualty count will probably increase as more news >filters out. > >There were no pictures in the report, and the story was followed >immediately with pictures from Mars. I was struck by the fact that we >could get pictures from Mars but not from Venezuela. > >Doug Crice > > > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm Q-BIT'SLAWNo.9: INTERCHANGEABLEPARTS-WON'TBE Q-BIT'SLAWNo.10: ANY WIRING ERRORINANYCONSTRUCTIONWILLBEIN THE DIRECTION OF THE MOST DAMAGE Q-BIT'SLAWNo.13:IDENTICALPARTSAREN'T _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson Subject: Re: cables Date: Fri, 11 Jul 1997 12:54:22 +1200 all, on one of my sensors I am using 30 metres (~100ft) of RG59 (75 Ohm) coax cable between the seismometer and the pre-amp (that I use) the non seismic noise is virtually unmeasureable. the two seismometers that are on the digital system are fed to the preamps with a 10 metre (~30 ft) of twin core screened computer data cable and again the unwanted noise level is unmeasurable obviously pre-amp input arrangement may be a factor I am planning to try one of Larry C's pre-amps to see the difference between it and the three I currently use Dave N. At 09:13 AM 7/10/97 -0700, you wrote: >Larry Cochrane wrote: > >> The problem is your are dealing with low levels of signal and the high >> impedance of the pickup coil. 12 to 15 feet of good shielded audio or RF >> cable should be fine. The thing to do is try it and see how much extra >> noise you get with the added cable. What you can do is see how much >> background noise (Min/Max A/D counts) you get with the pickup coil >> connected to the amp card with a small amount of cable. Then add the extra >> cable and see if the noise goes up much. This test should be done without >> the coil near a magnet. >> >> Hope this helps. >> > et al, > This is a good case for the afore mentioned suggestions of > using a differential input amplifier configuration on the coil > input and a 4-20mA current loop for the output. A current to > voltage converter ( easier than it sounds) would interface to > the A to D. > > Burr-Brown has a hot new 4-20mA IC called a XTR105 along with > other current transmitter IC'S at burr-brown.com. > > If you're going remote, Linx tech. in Medford, Or. sells > very small single-in-line package data radio transmitters and > receiver boards that work at up to 800'. > > I found a way to get a linear, high sensitivity output from > a 25mV/gauss MicroSwitch Linear Hall Effect Device. The problem > is that the output is dc and getting the #*$?@~! magnet centered > to the LOHET face for zero is impossible. So now I'm trying > to use it in a vertical force-balanced sensor so that it will > auto-zero itself. > > Regards, > > Jim cristiano@........... > > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm Q-BIT'SLAWNo.9: INTERCHANGEABLEPARTS-WON'TBE Q-BIT'SLAWNo.10: ANY WIRING ERRORINANYCONSTRUCTIONWILLBEIN THE DIRECTION OF THE MOST DAMAGE Q-BIT'SLAWNo.13:IDENTICALPARTSAREN'T _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: Venezuela quake Date: Thu, 10 Jul 1997 21:54:55 -0600 Martin- That is a very beautiful set of wiggles you recorded from Venezuela. It took me a little while to get my act together to look at them, but I am very impressed. -Edward -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Al Allworth Subject: Re: Transmitting signal Date: Thu, 10 Jul 1997 23:40:19 -0700 At 07:48 PM 7/10/97 -0300, you wrote: > >Thank you for your suggestion. I might have to set the second sensor in a >more remote location than I would like to, in which case I might want to >learn more about the solution you suggest. I am relatively ignorant in >this area and will need some help if it gets to that stage. Another suggestion: Since an op-amp input is often used, just put the input resistor at the remote site, use a good low noise cable, and connect the cable directly to the neg. input of the op amp. Sometimes a small portion of the input resistance needs to be at the op-amp. I have used this system successfully in other applications. It should work for this as well. The ground shield needs to be well connected at both ends. ____________________________________________________________________________ Al Allworth, Gold Beach, OR aallworth@........ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: John Hernlund Subject: Re: GeoPhone? Date: Fri, 11 Jul 1997 00:01:24 -0700 (MST) On Thu, 10 Jul 1997, Larry Cochrane wrote: > I'm not sure about that... Short period sensors, like geophones, are fine > for local and larger regional events but are not good for teleseismic > events. Short period velocity sensors just can't pickup, or resolve, the > low frequency waves from distant events. I think a Lehman (or modified SG > sensors), is a little more "general purpose" do to its broader frequency > range. A Lehman, with a period over 10 seconds, can be used for both local > and teleseismic events. > > The SG sensor (see http://psn.quake.net/sgsensor.html) design can be > modified to recording local events better by taking a signal out of the > sensors before the integrator. This creates a signal that has more high > frequency information and is better for viewing local events. I think it is interesting that such a basic design like the Lehman can be so useful. I have been thinking about some day building a small array of them. Each would respond well to different frequencies simply by altering the angle and/or length of the boom. Has anyone here ever tried this? ****************************************************************************** John Hernlund E-mail: hernlund@....... WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: GeoPhone? Date: Fri, 11 Jul 1997 09:03:28 -0600 Content-Transfer-Encoding: 7bit John- The Soviets builts a strong motion instrument that consisted of several different pendulums with diiferent natural frequencies. This device constituted, in effect, a coarse analog spectrum analyzer. However, by digitally recording a "broad-band" sensor, one can obtain the same information by digitally narrow-band filtering the broad-band signal at different frequencies, e.g., this can be done with Larry's WinQuake. -Edward John Hernlund wrote: > > On Thu, 10 Jul 1997, Larry Cochrane wrote: > > I'm not sure about that... Short period sensors, like geophones, are fine > > for local and larger regional events but are not good for teleseismic > > events. Short period velocity sensors just can't pickup, or resolve, the > > low frequency waves from distant events. I think a Lehman (or modified SG > > sensors), is a little more "general purpose" do to its broader frequency > > range. A Lehman, with a period over 10 seconds, can be used for both local > > and teleseismic events. > > > > The SG sensor (see http://psn.quake.net/sgsensor.html) design can be > > modified to recording local events better by taking a signal out of the > > sensors before the integrator. This creates a signal that has more high > > frequency information and is better for viewing local events. > > I think it is interesting that such a basic design like the Lehman can > be so useful. I have been thinking about some day building a small array > of them. Each would respond well to different frequencies simply by > altering the angle and/or length of the boom. Has anyone here ever tried > this? > > ****************************************************************************** > > John Hernlund > E-mail: hernlund@....... > WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ > > ****************************************************************************** > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Floyd Schad Subject: Re: GeoPhone? Date: Fri, 11 Jul 1997 08:38:05 -0700 Edward Cranswick wrote: > > Content-Transfer-Encoding: 7bit > > John- > The Soviets builts a strong motion instrument that consisted of several > different pendulums with diiferent natural frequencies. This device > constituted, in effect, a coarse analog spectrum analyzer. However, by > digitally recording a "broad-band" sensor, one can obtain the same > information by digitally narrow-band filtering the broad-band signal at > different frequencies, e.g., this can be done with Larry's WinQuake. > -Edward > > John Hernlund wrote: > > > > On Thu, 10 Jul 1997, Larry Cochrane wrote: > > > I'm not sure about that... Short period sensors, like geophones, are fine > > > for local and larger regional events but are not good for teleseismic > > > events. Short period velocity sensors just can't pickup, or resolve, the > > > low frequency waves from distant events. I think a Lehman (or modified SG > > > sensors), is a little more "general purpose" do to its broader frequency > > > range. A Lehman, with a period over 10 seconds, can be used for both local > > > and teleseismic events. > > > > > > The SG sensor (see http://psn.quake.net/sgsensor.html) design can be > > > modified to recording local events better by taking a signal out of the > > > sensors before the integrator. This creates a signal that has more high > > > frequency information and is better for viewing local events. > > > > I think it is interesting that such a basic design like the Lehman can > > be so useful. I have been thinking about some day building a small array > > of them. Each would respond well to different frequencies simply by > > altering the angle and/or length of the boom. Has anyone here ever tried > > this? > > > > ****************************************************************************** > > > > John Hernlund > > E-mail: hernlund@....... > > WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ > > > > ****************************************************************************** > > > > _____________________________________________________________________ > > > > Public Seismic Network Mailing List (PSN-L) > > > > To leave this list email listserver@............. with the body of the > > message: leave PSN-L > > -- > Edward Cranswick Tel: 303-273-8609 > US Geological Survey, MS 966 Fax: 303-273-8600 > PO Box 25046, Federal Center cranswick@........ > Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert L Barns <75612.2635@..............> Subject: Re: Homebrew Lehman Date: Fri, 11 Jul 1997 15:13:58 -0400 Martin, No, you are right. The P & S will have somewhat higher freq. components--prob. up to 1 Hz. or so but even at these freqs., I would not= expect any unwanted resonances. Bob Barns _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: John Hernlund Subject: Re: GeoPhone? Date: Fri, 11 Jul 1997 15:10:17 -0700 (MST) On Fri, 11 Jul 1997, Edward Cranswick wrote: > Content-Transfer-Encoding: 7bit > > John- > The Soviets builts a strong motion instrument that consisted of several > different pendulums with diiferent natural frequencies. This device > constituted, in effect, a coarse analog spectrum analyzer. However, by > digitally recording a "broad-band" sensor, one can obtain the same > information by digitally narrow-band filtering the broad-band signal at > different frequencies, e.g., this can be done with Larry's WinQuake. > -Edward Yes, I already use this method, but fancy analysis cannot always correct for the inefficiencies of the physical device, especially if it does not respond at all to some frequencies... ****************************************************************************** John Hernlund E-mail: hernlund@....... WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Martin Brewer" Subject: Re: Venezuela quake Date: Fri, 11 Jul 1997 21:24:37 -0300 > From: Edward Cranswick > Subject: Re: Venezuela quake > Date: Friday, July 11, 1997 12:54 AM > > Martin- > That is a very beautiful set of wiggles you recorded from Venezuela. > It took me a little while to get my act together to look at them, but I > am very impressed. > -Edward > Edward, Thank you for your kind comments. I can't believe how well this all works. Regards, Martin _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Martin Brewer" Subject: Re: Transmitting signal Date: Fri, 11 Jul 1997 21:31:15 -0300 ---------- > From: Al Allworth > Subject: Re: Transmitting signal > Date: Friday, July 11, 1997 3:40 AM > > At 07:48 PM 7/10/97 -0300, you wrote: > > > > >Thank you for your suggestion. I might have to set the second sensor in a > >more remote location than I would like to, in which case I might want to > >learn more about the solution you suggest. I am relatively ignorant in > >this area and will need some help if it gets to that stage. > > Another suggestion: > Since an op-amp input is often used, just put the input resistor at the > remote site, use a good low noise cable, and connect the cable directly to > the neg. input of the op amp. Sometimes a small portion of the input > resistance needs to be at the op-amp. I have used this system successfully > in other applications. It should work for this as well. The ground shield > needs to be well connected at both ends. > ____________________________________________________________________________ > > Al Allworth, Gold Beach, OR aallworth@........ Al, Thank you for your suggestion. There seems to be many ways to skin this cat. When I get that far down the road and need help with the details, I shall undoubtedly have to pick your brains and those of everyone else who has contributed to solving my problem. Thanks everyone. Regards, Martin _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Martin Brewer" Subject: Re: Homebrew Lehman Date: Fri, 11 Jul 1997 21:51:13 -0300 ---------- From: Robert L Barns <75612.2635@..............> Subject: Re: Homebrew Lehman Date: Friday, July 11, 1997 4:13 PM Martin, No, you are right. The P & S will have somewhat higher freq. components--prob. up to 1 Hz. or so but even at these freqs., I would not expect any unwanted resonances. Bob Barns Hi Bob, I shall keep your comments in mind as I go forward with .BER E-W. I am picking up background of micro-seismic activity with much increased amplitude (doubled) as Tropical Storm Bill passes within 150 miles or so. Unexpectedly (for me), the period of the waves has only increased slightly from about 3.7 to about 4.1. I would have expected a much greater increase in period. Perhaps there is some kind of integration effect in the water/bedrock system that keeps the general microseismic activity fairly constant. Are you seeing any effects there in New Jersey from T.S. Bill? Regards, Martin _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: frankcnd@.......... (Frank Condon) Subject: Animals are Strange! Date: xMessageSize=2000000 Hello all: I thought that I'd report this information obtained from a friend in the NW San Bernardino, CA area: This is in the same area where a 4.2 temblor struck about two weeks ago. The people who live in the area say that their pets are acting very strange! This includes both dogs and cats. I don't know if this means anything... But, I still wanted to be able to report it before something did happen again. I have an interest in watching animals myself and have witness bizarre behavior in equestrians on two ocassions before earthquakes and once with canines. Best regards, Frank Condon "In the High Desert of California" Email to: "frankcnd@.........." _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: frankcnd@.......... (Frank Condon) Subject: San Bernardino, CA Earthquake Swarm! Date: xMessageSize=2000000 Hi all: Well, I wasn't sure if anything would come out of the prediction made on July 11, 1997. Once again, animals have shown us that they are indeed another method of seismic prediction! On July 12, 1997; a swarm of earthquakes ( aftershocks) were observed in the area of the prediction. This is in the area 3-4 miles NW of the city closest to the epicenter of the 4.2 that occurred two weeks ago yesterday. This is the largest of the swarm that was observed according to information from the CALTECH finger server: ============================================================================= DATE UTC LAT. LON. DEPTH MAG. Q COMMENT yy-mm-dd hh:mm:ss (deg.) (deg.) (km) typ -------- -------- -------------- ------ ------ - ---------------------------- 97/07/12 18:05:40 34.15N 117.34W 9.4 3.6MLG A 4mi. NW of SAN BERNARDINO I'd say "people should keep an eye on those pets!" Especially, if they're in an area prone to earthquakes. If you see anything odd, or can add to this observation, then I'd appreciate hearing from you! Thanks, Frank Condon "In the High Desert of So. California" Email to: "frankcnd@.........." _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson Subject: Re: Meteor & Seismic Detectors Date: Mon, 14 Jul 1997 00:13:35 +1200 Walt, this is very expensive, Larry Cochrane's SDR logging system and Winquake software is ~ half the price and you have data compatability with many othersin the PSN group Dave At 05:08 PM 7/10/97 +0000, you wrote: >Hello All, > >I stumbled onto this "seismic instrument" while doing my search for >low frequency anomaly detectors. Probably a very simple instrument? > >See: >http://www.nitehawk.com/rasmit/jml0.html > >"EARTHQUAKE GROUND VELOCITY SENSOR > >Radio Astronomy Supplies is pleased to offer the FRANKLIN Ground >Velocity Sensor. This system is the first portable and user friendly >instrument ever produced, for recording earthquake and ground motion >signals. You can record and view signals hundreds of times smaller >than can be felt! This plug and go system simply attaches to your >computer's serial port. Windows or DOS software included (please >specify). " > > >Cheers, > >Walt Williams, 97.07.10 >Woodland Hills, California, >USA >dfheli@.............. > > > > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: John Hernlund Subject: New events on a new machine Date: Sun, 13 Jul 1997 16:38:29 -0700 (MST) Hi Everyone, This weekend I have been getting some type of events on the seismograph periodically and with varying duration. At first it looked too plain to be seismic and I thought it might have been the AC unit in the building or something, but I checked and the AC is not on over the weekend. The frequency is about 1.8 Hz according to Winquake. I was wondering if seismic events could be levelled out due to the seismometer being inside a building sitting on the foundation. I uploaded an example of one of these events to my web site. Here is the URL: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/EXAMPLE.CH1 If anyone has a chance, please look at it and give me your input. I want to get the seismometer in a hole soon, and the best way for that to happen is to show the people in charge here that we are recording actual seismic events, and that putting it in the hole will greatly improve the resolution... ****************************************************************************** John Hernlund E-mail: hernlund@....... WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson Subject: Re: New events on a new machine Date: Mon, 14 Jul 1997 12:56:46 +1200 John, the larger burst lasts for some 13 minutes there isn't a backup power generator for the building that was operating at the time??? on its weekly monthly test run ??? they cause plenty of higher freq vibrations!! It is very similar to the signal produced on the system I installed at the local civil def. HQ every time they fire up their gene. ( they run their one for 15 - 20 mins once a month. Dave N. At 04:38 PM 7/13/97 -0700, you wrote: >Hi Everyone, > This weekend I have been getting some type of events on the >seismograph periodically and with varying duration. At first it looked >too plain to be seismic and I thought it might have been the AC unit in >the building or something, but I checked and the AC is not on over the >weekend. The frequency is about 1.8 Hz according to Winquake. I was >wondering if seismic events could be levelled out due to the seismometer >being inside a building sitting on the foundation. I uploaded an example >of one of these events to my web site. Here is the URL: > > > If anyone has a chance, please look at it and give me your input. I >want to get the seismometer in a hole soon, and the best way for that to >happen is to show the people in charge here that we are recording actual >seismic events, and that putting it in the hole will greatly improve the >resolution... Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Seisguy@....... Subject: Re: New events on a new machine Date: Sun, 13 Jul 1997 21:54:08 -0400 (EDT) In a message dated 97-07-13 21:02:04 EDT, you write: << John, the larger burst lasts for some 13 minutes there isn't a backup power generator for the building that was operating at the time??? on its weekly monthly test run ??? they cause plenty of higher freq vibrations!! It is very similar to the signal produced on the system I installed at the local civil def. HQ every time they fire up their gene. ( they run their one for 15 - 20 mins once a month. Dave N. >> What are all those bursts on the KNBC seismocam? Check out URL:http://www.knbc4la.com/seismo/images/seismoNow.jpg Mike O Northridge, CA 7/13/97 _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: John Hernlund Subject: Re: New events on a new machine Date: Sun, 13 Jul 1997 21:49:47 -0700 (MST) On Mon, 14 Jul 1997, David A Nelson wrote: > John, > the larger burst lasts for some 13 minutes there isn't a backup > power generator for the building that was operating at the time??? on its > weekly monthly test run ??? they cause plenty of higher freq vibrations!! > It is very similar to the signal produced on the system I installed at > the local civil def. HQ every time they fire up their gene. ( they run their > one for 15 - 20 mins once a month. > > Dave N. Dave, That could be. I'll check on that when I can. Would the system produce activity at that frequency (1.8 Hz)? ****************************************************************************** John Hernlund E-mail: hernlund@....... WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson Subject: Re: New events on a new machine Date: Mon, 14 Jul 1997 22:05:42 +1200 just their recorder playing up again.... it seems to suffer from many problems, overwriting of the previous line, producing a thick black one, multitudes of spikes, etc But all the crud at the start of todays record is about the worst I have seen it yet. oh well at least it works well the majority of the time Dave > >> >What are all those bursts on the KNBC seismocam? > >Check out URL:http://www.knbc4la.com/seismo/images/seismoNow.jpg > >Mike O >Northridge, CA >7/13/97 > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jim Hannon Subject: Re: New events on a new machine Date: Mon, 14 Jul 1997 06:02:20 -0500 John Hernlund wrote: > > Dave, > That could be. I'll check on that when I can. Would the system > produce activity at that frequency (1.8 Hz)? > > ****************************************************************************** > > John Hernlund > E-mail: hernlund@....... > WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ > > ****************************************************************************** > > _____________________________________________________________________ > > John, You need to consider that the frequency could be higher and aliased down to 1.8 Hz by your sampling rate. -- Jim Hannon http://soli.inav.net/~jmhannon/ 42,11.90N 91,39.26W _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Charlie & Terri Thompson Subject: Re: Homebrew Lehman Date: Mon, 14 Jul 1997 20:49:46 -0500 I'm posting the following answers to Nick's questions to the PSN list in case anybody else is interested. Nick asks: > > I would like to know the distance between the Copper Damper plate and the >pickup coil. > ANS: The copper damper plate is about 8 inches from the pickup coil. > Do have any trouble keeping the Bolt end ( that is ground sharp) in place >with the horizontal threaded rod? > ANS: The horizontal threaded rod has a small indentation (made by a drill bit) with a drop of oil. The sharpened point mates into the indentation thus keeping the rod from slipping off the sharpened point. In general...tuning the Lehman for as long a period as possible, keeping it in a thermally stable box, and placing it in a quiet place (like on the slab in a distant part of your garage) is what really makes a difference. Exact dimensions of the Lehman can be improvised upon to suit your own style. Levelling screws are extremely useful as well. Small slabs are a bad idea if you want to keep it adjustment-free. Small slabs can shift when it rains (at least here in the Texas soil anyway). Hope this helps. -Charlie _ ________________________________________________ _ / ) | | ( \ / / | Charlie Thompson WB4HVD | \ \ _( (_ | _ e-mail: xctx@....... _ | _) )_ (((\ \> |/ ) http://www.onr.com/user/ct/ct.html ( \| Subject: [Fwd: Re: Failed mail: unknown user] Date: Mon, 14 Jul 1997 21:15:35 -0700 From: lahr@................. (Dr. John Lahr (USGS-GI Seismologist)) Subject: Re: TAC Clock Date: Tue, 15 Jul 1997 09:23:06 -0800 Larry, Have you looked into Tom Clark's Totally Accurate Clock (TAC)? The Tucson Amateur Packet Radio Corp (TAPR) sells kits for making the clock, which is based on a GPS receiver. Their web page is: http://www.tapr.org/tapr/html/tac2.html This would be a big improvement over WWV, especially for Alaska, where the WWV signal is too weak to receive well. Looks like the total cost would be ~$250, which includes the TAC kit and an OEM GPS unit. JCLahr ################################## John C. Lahr ################################# Seismologist ################################ U.S. Geological Survey ############################### c/o Geophysical Institute ############################## 903 Koyukuk Drive ~~~~~~~~~~~~~~ Get ~~~~~~~~~~ ############################# ########################################################### P.O. Box 757320 ################################ Fairbanks, AK 99775 ################################# Phone: (907) 474-7997 ################################## Fax: (907) 474-5618 ~~~~~~~~ the thrust? ~~~~~~~~~~~~~~ lahr@........ #################################### http://www.aeic.alaska.edu/Input/lahr/ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Re: TAC Clock Date: Tue, 15 Jul 1997 15:36:51 -0700 Hi John and Others, >At 09:23 AM 7/15/97 -0800, you wrote: >Larry, > >Have you looked into Tom Clark's Totally Accurate Clock (TAC)? >The Tucson Amateur Packet Radio Corp (TAPR) sells kits for making >the clock, which is based on a GPS receiver. Their web page is: > http://www.tapr.org/tapr/html/tac2.html > >This would be a big improvement over WWV, especially for Alaska, >where the WWV signal is too weak to receive well. Looks like >the total cost would be ~$250, which includes the TAC kit and >an OEM GPS unit. Yes I have... Looks interesting but the unit still needs an antenna, power supply, box and low loss coax, so the cost is more then $250.00. I would like to add this option to SDR, but I don't have an extra 250+ dollars too play around with. I just had to pay $600.00 for a permanent key for the email server I am using. Part of the server runs this list. More about this later... Also, since WWV works fine for me (and other PSN stations) I don't personally need it. If someone wants this option I would be more then happy to added it to SDR. BUT, you would have to buy the receiver, antenna etc, get it working, and then send it to me so I can work with it. -Larry Cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: lahr@................. (Dr. John Lahr (USGS-GI Seismologist)) Subject: Re: PSN Finances - a suggestion Date: Tue, 15 Jul 1997 16:53:58 -0800 PSN Members, I think the time has come to help Larry Cochrane out with some of the out-of-pocket expenses related to hosting the PSN Email server. We could never afford to pay him for all of the time he puts in! What do others think about this? Perhaps we could run it like public TV and radio, with suggested annual donation notices posted at the bottom of each listserver message. Perhaps the PSN web page could include a listing of all of the Email subscribers with the amount(s) and years(s) of their donation(s). Larry could also list the expenses he has had to pay so that we could try to keep things fairly balanced. JCLahr ################################## John C. Lahr ################################# Seismologist ################################ U.S. Geological Survey ############################### c/o Geophysical Institute ############################## 903 Koyukuk Drive ~~~~~~~~~~~~~~ Get ~~~~~~~~~~ ############################# ########################################################### P.O. Box 757320 ################################ Fairbanks, AK 99775 ################################# Phone: (907) 474-7997 ################################## Fax: (907) 474-5618 ~~~~~~~~ the thrust? ~~~~~~~~~~~~~~ lahr@........ #################################### http://www.aeic.alaska.edu/Input/lahr/ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: Re: PSN Finances - a suggestion Date: Tue, 15 Jul 1997 19:36:28 -0700 John I second the motion. I think a annual donation would be appropriate. I don't mind listing the contributors but I don't know about the amount. Barry Dr. John Lahr (USGS-GI Seismologist) wrote: > > PSN Members, > > I think the time has come to help Larry Cochrane out with > some of the out-of-pocket expenses related to hosting the > PSN Email server. We could never afford to pay him for all > of the time he puts in! > > What do others think about this? Perhaps we could run > it like public TV and radio, with suggested annual donation > notices posted at the bottom of each listserver message. > > Perhaps the PSN web page could include a listing of all of > the Email subscribers with the amount(s) and years(s) of their > donation(s). Larry could also list the expenses he has had > to pay so that we could try to keep things fairly balanced. > > JCLahr _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Karl Cunningham Subject: Re: PSN Finances - a suggestion Date: Tue, 15 Jul 1997 23:39:40 -0700 At 04:53 PM 7/15/97 -0800, Dr. Lahr wrote: > >PSN Members, > >I think the time has come to help Larry Cochrane out with >some of the out-of-pocket expenses related to hosting the >PSN Email server. We could never afford to pay him for all >of the time he puts in! Here Here!! I agree completely. My $.02: My suggestion would be to try a purely voluntary system of donations first, with no accounting of payments by individual. This would avoid having to keep track of who has donated and who has not, avoid the awkward situation of asking people to pay up, and avoid the even more awkward situation of asking someone to pay who really cannot afford it. My fear is that there may be some who can't afford dues (students, for example), who subscribe out of interest, yet may feel uncomfortable continuing to subscribe if a donation is expected. I would, from time to time, like to see what expenses Larry has encountered and what income he has gotten to offset them. This might allow all of us to know where we stand and to help Larry out when needed. Another aspect that (I think) deserves attention is to make sure that whatever happens with money (dontations) is consistent with the IRS's understanding of the PSN's status, whatever that might be. I'm willing to go along with whatever system is ultimately decided upon. Karl Cunningham La Mesa, CA. karlc@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: John Hernlund Subject: Re: PSN Finances - a suggestion Date: Wed, 16 Jul 1997 00:54:41 -0700 (MST) On Tue, 15 Jul 1997, Dr. John Lahr (USGS-GI Seismologist) wrote: > > PSN Members, > > I think the time has come to help Larry Cochrane out with > some of the out-of-pocket expenses related to hosting the > PSN Email server. We could never afford to pay him for all > of the time he puts in! I think this is a great idea. This server has been a great benefit to me, also we should mention Larry's software! I for one have never encountered that kind of quality for free. I don't know how he has time to do all of this and earn a living for himself. Why don't we just start out by giving him what we can on our own and see how it goes? Too much other stuff could make more work for Larry, which is not our intention. ****************************************************************************** John Hernlund E-mail: hernlund@....... WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Martin Brewer" Subject: N. Mid-Atlantic Ridge events Date: Wed, 16 Jul 1997 12:25:13 -0300 Hello All, Bermuda picked up some at least of the Northern Mid-Atlantic ridge 'quakes beginning at 10:43 UTC 16 July 1997. Did anyone else pick up these? Martin _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: shammon1@............. Subject: Re: PSN Finances - a suggestion Date: Wed, 16 Jul 1997 09:27:02 -0700 Dr. John Lahr (USGS-GI Seismologist) wrote: > > PSN Members, > > I think the time has come to help Larry Cochrane out with > some of the out-of-pocket expenses related to hosting the > PSN Email serv > > JCLahr I agree John. Larry, how about a donation address to support the WEB site operation? Regards, Steve Hammond -- PSN San Jose, California _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Nick & Sophie Caporossi Subject: PSN Contributions Date: Wed, 16 Jul 1997 14:56:58 -0400 I also think that Larry's effort and expenses should be compensated. The PSN web page could include a listing of all of the Email subscribers who had contributed to the maintenance of the psn-l quake site, that should be sufficient. I don't think you'l want to disclose a dollar amount on a web page. Nick Caporossi _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Peter Styles Subject: Re: PSN Contributions Date: Wed, 16 Jul 1997 13:03:12 BST As an overseas user and head of a small research group at the University of Liverpool who have benefited greatly from Larry's efforts we would be very willing to make an annual contribution to PSN. The guy is doing a great job, lets make sure he doesn't bankrupt himself doing it. Peter Styles On Wed, 16 Jul 1997 14:56:58 -0400 Nick & Sophie Caporossi wrote: > From: Nick & Sophie Caporossi > Date: Wed, 16 Jul 1997 14:56:58 -0400 > Subject: PSN Contributions > To: "psn-l@............." > > I also think that Larry's effort and expenses should be compensated. > The PSN web page could include a listing of all of the Email subscribers > who had contributed to the maintenance of the psn-l quake site, that should > be sufficient. I don't think you'l want to disclose a dollar amount on a > web page. > > Nick Caporossi > > ____________________________________________________________ _________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L Home: 6 Swan Lane Bunbury Tarporley Cheshire CW6 9RA 01829 260808 Work: Department of Earth Sciences University of Liverpool Brownlow Street Liverpool L69 3BX (44) 0151 794 5174 _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: JHammes@......................... Subject: Re[2]: PSN Contributions Date: Wed, 16 Jul 1997 14:44:49 -0700 Yo, Larry, So give us an address where those who wish can swing some dough towards your Redwood City PSN support fund. Forget the posted list of contributors; wouldn't want to start an elitist group of righteous snobs now would we. Jerry Hammes jhammes@.................. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: PSN Contributions Date: Wed, 16 Jul 1997 14:30:42 -0700 Hi, Just to let everyone know, I'm working on a letter too the list. I have to go to a meeting for a few hours. When I get back I will finish it and send it out. -Larry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Ken Navarre Subject: Re: PSN Contributions Date: Wed, 16 Jul 1997 20:30:35 -0700 (PDT) On Wed, 16 Jul 1997, Larry Cochrane wrote: > Hi, > > Just to let everyone know, I'm working on a letter too the list. I have to > go to a meeting for a few hours. When I get back I will finish it and send > it out. Unless you're going to vote yes on the matter of PSN contributions, don't bother to post your letter. I think you're going to be outvoted! :) I know that the R&D costs that you've encountered developing the software and the hardware for the PSN group FAR outweights the monitary rewards that you've reaped. I remember the first demod board that you put out following the PSN meeting in SJC. *ALL* of us at one time or another have wanted to get involved in the seismo watch and couldn't have had anywhere near the pleasure and rewards if each of us had to develop this stuff on our own. The software is right up there with the best commercial stuff in many categories - especially tech support! The hardware is perfect! We just gotta get a "membership" donation up and running. IF someone can't afford it that's fine. I know that you will still offer help and services. As one of those who can afford it, I want to be among the first to offer a token of appreciation for the work you've done. I'd hate to put you in a different tax bracket so I'd prefer to make the donation personal rather than to the organization but will abide by the wishes of the recipient... :) Ken _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Re: PSN Finances Date: Wed, 16 Jul 1997 22:31:47 -0700 Greetings, First I would like to thank everyone who offered to help... I thought I would give some background information for the new members on my system and what it is I bought to keep this list going. I started the Redwood City PSN site about 2 years ago. At that time I got a full time connection with a ISP called QuakeNet. With a name like that how could I refuse.... What I have is a 28.8k connection to QuakeNet using a standard phone line. They installed a modem and phone line that I exclusively dial into at their end. Since my system is in my house, the phone call is not metered and all I have to pay for is an extra phone line, about $14.00 per month. It would be nice to move up to a higher speed connection but the cost goes up very quickly. For the full time 28.8k connection I pay QuakeNet $105.00 per month. After I got my system online I looked around for a email server for Windows NT. I settled on one from England called NTMail (see http://www.ntmail.co.uk). The problem was it was/is expensive but luckily they gave out a free key each month that would allow the software to run for one month but with limits on how many accounts and lists it would handle. About two months ago they stopped giving out free keys. I was feeling guilty for using their software for free anyway so I didn't mind finally buying the software. The minimum configuration of NTMail cost $600.00. This allows me to have 1 to 5 mailing lists, 10 user accounts and 1 to 5 domains. I only need 2 domains, webtronics.com and psn.quake.net, a few user accounts, and one mailing list (this one). If you look at the price list for NTMail 1 - 5 email lists cost $200.00. Each mailing list also uses up 1 user account, another $200.00 and it needs a domain name, another $200.00. What I would like help on is paying for 1/2, $300.00 or more, of the cost of NTMail. Since I use part of the program for my personal usage (though 95% is EQ related) I think I should pay for some of it. Now how to do this... I agree with Karl Cunningham that people on fixed income should not have to pay. At this point all I'm asking for is some help paying for the mail server. If people want to help with the monthly cost of running my system that's fine, but helping to pay for the server is all I'm asking for. The hard part is how much. I think it depends on how many people are willing to help. The list currently has 255 members. If only 10 people help, then $30.00 each would pay for 1/2 the cost. If 100 send in money then it could be as low as $3.00 each (less then a 6 pack of beer). Maybe the thing to do is find out how many can help and work from there. This can be done by sending me email and I will tally them up and report back in a few days. We can then determine what the minimum "donation" would be. If people want to pay more that's fine. If I get more then $600.00 I will put the money into the monthly cost of operating the system. The "donation" is NOT tax deductible. PSN is not an official nonprofit organization with the IRS (and I think we should keep it that way. Sounds like a lot of paper work to me...). Also your check would have to be made out to me. I can't cash a check made out to PSN. One more think... I thought I would explain the relationship between the Redwood City PSN, Webtronics and me. Webtronics was a company (partership) that a friend and I started about 2 years ago. We where hoping to start a Web hosting business but it never took off. At this point its dead... You may have noticed that I remove the Webtronics logo from the PSN site several days ago. I also remove the weather satellite picture and link. This is because my NOAA receiver / demodulator stopped working and I don't have time to fix it. Anyway, Webtronics.com at this point is only a domain registered to me and not an active company. At some point I will probably drop the Webtronics.com name and use SeismicNet.com. I registered this domain name a while back. The domain name psn.quake.net belongs to my ISP. If I ever move ISP's I will loss this name. That's it. If anyone has any questions or has some suggestions please let me know. Regards, Larry Cochrane Redwood City,PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Re: PSN Finances - a suggestion Date: Thu, 17 Jul 1997 00:31:46 -0700 At 11:39 PM 7/15/97 -0700, Karl Cunningham wrote: >My suggestion would be to try a purely voluntary system of donations first, >with no accounting of payments by individual. This would avoid having to >keep track of who has donated and who has not, avoid the awkward situation >of asking people to pay up, and avoid the even more awkward situation of >asking someone to pay who really cannot afford it. My fear is that there >may be some who can't afford dues (students, for example), who subscribe >out of interest, yet may feel uncomfortable continuing to subscribe if a >donation is expected. I agree 100% > >I would, from time to time, like to see what expenses Larry has encountered >and what income he has gotten to offset them. This might allow all of us >to know where we stand and to help Larry out when needed. As I said in my previous post all I'm asking for is a one time donation to help pay for the email server. If people want to help out more, that's fine (see below). My Internet expenses are pretty much fixed and documented in my previous post. Part of the expenses I would have anyway, just to have an Internet connect (extra phone line and ISP etc). Another way of helping is by buying boards/systems from me. The sell of boards helps pay for the recurring cost of running my system. The problem is I would have to sell a lot of my boards to pay for the mail server. That's my I'm going too the list for help. Besides having to buy the mail server, I also had to buy another lot of A/D and Amp/Filter blank PC boards this month. I try to have as many boards made as possible to keep the cost down. The problem is I need to put out a lot of up front money and then get it back as I sell the boards. BTW Karl just bought a 16 bit A/D card from me, thanks Karl! I would also like to thank all of the other people who have bought equipment from me in the past. > >Another aspect that (I think) deserves attention is to make sure that >whatever happens with money (dontations) is consistent with the IRS's >understanding of the PSN's status, whatever that might be. That's an easy one... As far as I know the IRS knows nothing about the PSN. As I said before, I think we should keep it that way. Also, since I sell boards for profit I'm not sure how the whole thing would work. Regards, Larry Cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Dennis Leatart Subject: PSN Finance Date: Thu, 17 Jul 1997 08:10:04 -0700 Hi Larry! Could not contact you directly because your E-mail address would not work- so have to do it through PSN. I would be willing to donate whatever comes out fair-- just let us know. I would think that this should be a yearly donation? -- _____ __ | \.-----.-----.-----.|__|.-----. | -- | -__| | || ||__ --| |_____/|_____|__|__|__|__||__||_____| _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Terence Dowling Subject: Re: PSN Finances Date: Thu, 17 Jul 1997 08:56:49 -0700 I appreciate what you are doing and would be happy to contribute at the $30 level (or more if needed). -- Terence Dowling (408) 536-3856 Adobe Systems Inc. dowling@......... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: lahr@................. (Dr. John Lahr (USGS-GI Seismologist)) Subject: PSN Finances Date: Thu, 17 Jul 1997 11:13:32 -0800 What ever Larry decides for getting some help is fine with me. Count me in. However, I think we should shoot for more than just $300. Perhaps 12*105 + 300 = $1,560 would be more like it. If 100 of the 255 Email list members could help out, this would come to $15.60 each. JCLahr _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: lahr@................. (Dr. John Lahr (USGS-GI Seismologist)) Subject: TAC clock Date: Thu, 17 Jul 1997 11:19:19 -0800 Robert, I got some error (see below) when trying to reply to your message, so I'll try through the listserver, as this is PSN related. JCLahr > From Mailer-Daemon Thu Jul 17 11:00 AKD 1997 > Date: Thu, 17 Jul 1997 11:00:51 -0800 > From: Mailer-Daemon (Mail Delivery Subsystem) > Subject: Returned mail: Local configuration error > To: > To: postmaster > > The original message was received at Thu, 17 Jul 1997 11:00:50 -0800 > from spurr [137.229.32.20] > > ----- The following addresses had delivery problems ----- > <75612.2635@..............> (unrecoverable error) > > ----- Transcript of session follows ----- > 553 giseis.alaska.edu config error: mail loops back to myself > 554 <75612.2635@..............>... Local configuration error > > ----- Original message follows ----- > Return-Path: > Received: from spurr by giseis.alaska.edu (SMI-8.6/SMI-SVR4) > id LAA10464; Thu, 17 Jul 1997 11:00:50 -0800 > Received: by spurr (SMI-8.6/SMI-SVR4) > id LAA00232; Thu, 17 Jul 1997 11:07:54 -0800 > Date: Thu, 17 Jul 1997 11:07:54 -0800 > From: lahr@................. (Dr. John Lahr (USGS-GI Seismologist)) > Message-Id: <199707171907.LAA00232@spurr> > To: 75612.2635@.............. > Subject: Re: TAC Clock > X-Sun-Charset: US-ASCII > content-length: 607 > > > Robert, > > It looks like lots of people agree on helping Larry with > his PSN expenses - I was sure they would. > > As for the TAC clock, I just hate to see the entire world > radiated by satellites with a time code that is good to > much better than .001 s and not be able to sync a clock > to better than .5 s! The TAC is still a bit expensive, but > my dream would be to have the PSN clocks good to .01 s so > that arrival times could be used by NEIS or by local > networks. > > Once someone hacks the Zeit clock to bring out a signal, this > might have to do until a less expensive GPS option is > available. > > Cheers, > JCLahr > > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jim Hannon Subject: Re: TAC Clock Date: Thu, 17 Jul 1997 15:16:03 -0500 Dr. John Lahr (USGS-GI Seismologist) wrote: > > Larry, > > Have you looked into Tom Clark's Totally Accurate Clock (TAC)? > The Tucson Amateur Packet Radio Corp (TAPR) sells kits for making > the clock, which is based on a GPS receiver. Their web page is: > http://www.tapr.org/tapr/html/tac2.html > > This would be a big improvement over WWV, especially for Alaska, > where the WWV signal is too weak to receive well. Looks like > the total cost would be ~$250, which includes the TAC kit and > an OEM GPS unit. > > JCLahr > John, I have had some discussion with Larry about using GPS engines for the time and sent him the data on the Rockwell GPS engine. It is really not necessary to use the TAC hardware to support a GPS engine especially in the environment of Larry's A/D card ect. I have one of the Rockwell engines here being used in a radio location experiment for work. Similar to locating quakes by time of arrival except at light speed. It works well enough to locate a transmitter within less than a mile. When I get some time I am going to see what kind of price I can get on the Rockwell engines and incorporate it into my yet to be build seismograph. The problem I still need to solve is finding an inexpensive antenna. I bought an aircraft quality amplified antenna for $70 but there should be a source for something less. It would be great to have accurate enough time to really line up data from multiple stations. -- Jim Hannon http://soli.inav.net/~jmhannon/ 42,11.90N 91,39.26W _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Geotechnical Resources, Inc." Subject: PSN Finances Date: Thu, 17 Jul 1997 16:18:15 -0700 Count me in for whatever it takes. Bill Titus gri@............ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: JIM CRISTIANO Subject: Re: PSN Finances Date: Thu, 17 Jul 1997 16:45:30 -0700 Geotechnical Resources, Inc. wrote: > > Count me in for whatever it takes. Ditto for me. Jim cristiano@........... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: Contribution Date: Thu, 17 Jul 1997 17:00:49 -0700 Include me also Larry. I also think an annual amount would be appropriate. Barry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Clark Wockner Subject: Re: PSN Finances Date: Thu, 17 Jul 1997 21:34:20 -0700 Hi Gang: I think its is kind of hard for Larry to put a price on his work. I am going to send him a fresh 10 dollar bill tomorrow and I hope everyone on the list does likewise. That would bring in enough to pay his out of pocket cost, the monthly expense and replace some equipment when the time comes. Ok guys, fill his mail box. Regards Clark _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Joan Chesleigh-Blaine Subject: Finances-another suggestion Date: Thu, 17 Jul 1997 20:37:10 -0700 I think the "ground rules" for this most worth while fund raising project have been well outlined by Larry. We need just two very simple things: 1. An address to send our donations to and, 2. A name to make our checks payable to. That will do it! Thanks, Joan Blaine _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Re: Finances-another suggestion - My address Date: Thu, 17 Jul 1997 20:02:27 -0700 Thanks Joan, my address is: Larry Cochrane 24 Garden St. Redwood City, Ca. 94063 USA Checks should be made out to me. So far 20 people have signed up, thanks everyone! -Larry At 08:37 PM 7/17/97 -0700, you wrote: >I think the "ground rules" for this most worth while fund raising project have >been well outlined by Larry. >We need just two very simple things: > 1. An address to send our donations to and, > 2. A name to make our checks payable to. >That will do it! >Thanks, >Joan Blaine > > > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Roger Griggs Subject: Re: PSN Finances Date: Thu, 17 Jul 1997 21:02:25 -0700 At 10:31 PM 7/16/97 -0700, you wrote: >Greetings, > >First I would like to thank everyone who offered to help... > >That's it. If anyone has any questions or has some suggestions please let >me know. > >Regards, >Larry Cochrane >Redwood City,PSN > > Larry, I too would like to personally thank you for your diligent efforts and the unselfish time you have expended on the SDR software. I have had many enjoyable hours using the programs you have so graciously provided that have brought the hobby of siesmology within reach of lay persons around the world. Ya know they give awards to guys who do that kind of stuff? (The Richter Award?) Not only is it a great idea to help defer your expenses (also being quite necessary) but just possibly you could be in need of computer parts in the maintenance of your system. I for one could donate computers (486), hard drives, monitors, keyboards, etc should they be out of pocket expenses for you. Computers wear out sooner or later. You might consider posting a "PSN Wish List" for inprovements to the PSN web site. I'm sure some of those siesmic hackers out there have a few extra parts laying around that were going to get used in some project that never got off the drawing board. I couldn't think of a more deserving cause than the Redwood City PSN! Regards, Roger _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: Finances-another suggestion - My address Date: Thu, 17 Jul 1997 23:12:36 -0600 Larry- In my own mind, there has never been any question of my good intentions about my returning some of your tax dollars to you, and now since there has been such a wave of support propagating across the Web, I guess it's time for me to put the check in the mail, which I will gladly do. -Edward Larry Cochrane wrote: > > Thanks Joan, my address is: > > Larry Cochrane > 24 Garden St. > Redwood City, Ca. > 94063 USA > > Checks should be made out to me. > > So far 20 people have signed up, thanks everyone! > > -Larry > > At 08:37 PM 7/17/97 -0700, you wrote: > >I think the "ground rules" for this most worth while fund raising project > have > >been well outlined by Larry. > >We need just two very simple things: > > 1. An address to send our donations to and, > > 2. A name to make our checks payable to. > >That will do it! > >Thanks, > >Joan Blaine > > > > > > > >_____________________________________________________________________ > > > >Public Seismic Network Mailing List (PSN-L) > > > >To leave this list email listserver@............. with the body of the > >message: leave PSN-L > > > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Daryl P. Dacko" Subject: Re: PSN Finances Date: Fri, 18 Jul 1997 07:01:49 -0400 At 04:45 PM 7/17/97 -0700, you wrote: > >> Count me in for whatever it takes. > > Ditto for me. I just discovered this list, and after two weeks, I feel I can afford a bit of cash - this list is priceless ! Daryl _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: G Keith Still Subject: Finances-another suggestion Date: Fri, 18 Jul 1997 13:03:22 -0400 How do you get off this list - I've been trying for weeks. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: Finances-another suggestion - My address Date: Fri, 18 Jul 1997 11:06:06 -0600 Larry- If you were to simply post on the webpage somewhere the name of the donor and the date the contribution was received, this would confirm for the donor that the contribution had arrived at the right address, etc., i.e., this notice would take the place of a receipt. -Edward Edward Cranswick wrote: > > Larry- > In my own mind, there has never been any question of my good > intentions about my returning some of your tax dollars to you, and now > since there has been such a wave of support propagating across the Web, > I guess it's time for me to put the check in the mail, which I will > gladly do. > -Edward > > Larry Cochrane wrote: > > > > Thanks Joan, my address is: > > > > Larry Cochrane > > 24 Garden St. > > Redwood City, Ca. > > 94063 USA > > > > Checks should be made out to me. > > > > So far 20 people have signed up, thanks everyone! > > > > -Larry > > > > At 08:37 PM 7/17/97 -0700, you wrote: > > >I think the "ground rules" for this most worth while fund raising project > > have > > >been well outlined by Larry. > > >We need just two very simple things: > > > 1. An address to send our donations to and, > > > 2. A name to make our checks payable to. > > >That will do it! > > >Thanks, > > >Joan Blaine > > > > > > > > > > > >_____________________________________________________________________ > > > > > >Public Seismic Network Mailing List (PSN-L) > > > > > >To leave this list email listserver@............. with the body of the > > >message: leave PSN-L > > > > > > > _____________________________________________________________________ > > > > Public Seismic Network Mailing List (PSN-L) > > > > To leave this list email listserver@............. with the body of the > > message: leave PSN-L > > -- > Edward Cranswick Tel: 303-273-8609 > US Geological Survey, MS 966 Fax: 303-273-8600 > PO Box 25046, Federal Center cranswick@........ > Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Tom Frey" Subject: Re: PSN Finances Date: Fri, 18 Jul 1997 15:34:47 -0700 Count Me in too Larry! Tom Frey tfrey@........... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Eileen Clark Subject: Re: Finances Date: Fri, 18 Jul 1997 17:55:19 -0700 (PDT) Larry: "The Check is in the Mail!" Really!! Will your board interface with an AS-1 seismograph? We haven't been able to get an interface that is compatible with WinQuake. Steve Clark At 08:02 PM 7/17/97 -0700, Larry Cochrane wrote: >Thanks Joan, my address is: > >Larry Cochrane >24 Garden St. >Redwood City, Ca. >94063 USA > >Checks should be made out to me. > >So far 20 people have signed up, thanks everyone! > >-Larry > >At 08:37 PM 7/17/97 -0700, you wrote: >>I think the "ground rules" for this most worth while fund raising project >have >>been well outlined by Larry. >>We need just two very simple things: >> 1. An address to send our donations to and, >> 2. A name to make our checks payable to. >>That will do it! >>Thanks, >>Joan Blaine >> >> >> >>_____________________________________________________________________ >> >>Public Seismic Network Mailing List (PSN-L) >> >>To leave this list email listserver@............. with the body of the >>message: leave PSN-L >> > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: event Date: Sat, 19 Jul 1997 06:54:52 -0700 Well a good sized teleseism coming in even as I speak.Arrival at a little after 14:27 UTC. News at 11. Barry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jean-Jacques HUNSINGER Subject: Re: event Date: Sat, 19 Jul 1997 17:51:59 +0200 barry lotz wrote: > > Well a good sized teleseism coming in even as I speak.Arrival at a > little after 14:27 UTC. News at 11. > Barry > probably, i got the same beginning at 14:32 UTC here in France.... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: event file sizes Date: Sat, 19 Jul 1997 10:32:19 -0700 Hi all A suggestion - For teleseismic events (or any for that matter) It would be satisfactory to save event files at a sampling rate of no more than 10x the max frequency recorded. This would help with file sizes. Regards Barry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Dennis Leatart Subject: Re: event file sizes, GUERRERO QUAKE, MEXICO Date: Sat, 19 Jul 1997 11:34:40 -0700 I got a good trace of the Guerrero quake in Mexico reported as a mag 6.2. I am seeing what looks like two foreshocks spaced about 5 and 10 minutes before the main quake. Can anyone confirm this? I was about 2910km from the epicenter. I have a bmp image of the event in case anyone is interested-- it only takes 27Kbytes! Thanks and good day to all! -- _____ __ | \.-----.-----.-----.|__|.-----. | -- | -__| | || ||__ --| |_____/|_____|__|__|__|__||__||_____| _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Rev. Robert Shannon" Subject: Re: event file sizes, GUERRERO QUAKE, MEXICO Date: Sat, 19 Jul 1997 18:54:40 GMT At 11:34 AM 7/19/97 -0700, you wrote: >I got a good trace of the Guerrero quake in Mexico reported as a mag >6.2. I am seeing what looks like two foreshocks spaced about 5 and 10 >minutes before the main quake. Can anyone confirm this? I was about >2910km from the epicenter. I have a bmp image of the event in case >anyone is interested-- it only takes 27Kbytes! Thanks and good day to >all! As usual I will certainly be interested in your file..Please send Dennis and Great work! Bob Pinpoint _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Re: Finances-another suggestion - My address Date: Sat, 19 Jul 1997 13:51:49 -0700 At 11:06 AM 7/18/97 -0600, Edward wrote: >Larry- > If you were to simply post on the webpage somewhere the name of the >donor and the date the contribution was received, this would confirm for >the donor that the contribution had arrived at the right address, etc., >i.e., this notice would take the place of a receipt. >-Edward I can do that... What I will do is make up a Donations.html page with the names, but not the amount, I don't think that's necessary. I will post the total donations collected at the bottom of the page. Again, thanks to everyone who offered to help! Regards, Larry Cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Re: PSN Finances Date: Sat, 19 Jul 1997 13:54:16 -0700 Hi Tom, Thanks a lot! It's been a while since I have heard from you, how are thinks going. -Larry At 03:34 PM 7/18/97 -0700, you wrote: >Count Me in too Larry! > >Tom Frey >tfrey@........... > > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Re: PSN Finances - Sorry about that.... Date: Sat, 19 Jul 1997 14:00:57 -0700 Sorry about that, I meant this to go to Tom directly and not to the list! I hate it when I forget to look at the To field... -Larry >Hi Tom, > >Thanks a lot! It's been a while since I have heard from you, how are thinks >going. > >-Larry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Martin Brewer" Subject: Re: event Date: Sat, 19 Jul 1997 20:45:22 -0300 ---------- > From: barry lotz > Date: Saturday, July 19, 1997 10:54 AM > > Well a good sized teleseism coming in even as I speak.Arrival at a > little after 14:27 UTC. News at 11. > Barry Hi Barry and everyone else, Bermuda recorded a good trace of the Guerrero Mag 6.2 event. The P waves were picked up very well, unlike some earlier, smaller events. I am posting a Winquake file to the events address for comments please. The P and S picks were made to correspond to first P arrival and the correct great circle distance. The origin time works out to be very close to the USGS NEIC result. BUT the required pick for the first S arrival is in a relatively quiet region of the seismograph. I look forward to any explanation of the apparent discrepancy in the position of the S pick. Regards, Martin _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Martin Brewer" Subject: Surface waves at Bermuda Date: Sat, 19 Jul 1997 21:28:51 -0300 Hello Everyone, Since about 97/07/20 01:00 UTC Bermuda has been (and still is) recording long period (20s) waves with no apparent P and S associated. Is a large event in my Earth Core shadow zone happening? Maybe somewhere near Dave Nelson? Regards, Martin _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson Subject: Re: Surface waves at Bermuda Date: Sun, 20 Jul 1997 15:26:03 +1200 Martin, prob the surface waves of the Mw5.9 in the Fox Is. in the Aleutians (Nth Pac.) timing would be about right. Dave At 09:28 PM 7/19/97 -0300, you wrote: >Hello Everyone, > >Since about 97/07/20 01:00 UTC Bermuda has been (and still is) recording >long period (20s) waves with no apparent P and S associated. Is a large >event in my Earth Core shadow zone happening? Maybe somewhere near Dave >Nelson? > >Regards, >Martin > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: FCooper242@....... Subject: Re: Esterline-Angus Chart Paper Date: Sat, 19 Jul 1997 23:56:18 -0400 (EDT) Would anyone happen to have any extra rolls of Esterline-Angus Chart Paper to sell at a reasonable price? Thanks, Frank, Friendswood, Texas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: John Hernlund Subject: Variable Reluctance Seismometer Date: Sat, 19 Jul 1997 21:07:51 -0700 (MST) Hello All, I have found some literature on our seismometer finally (it was donated and I didn't have much information about it). It is a variable reluctance type seismometer designed by Hugo Benioff in 1930. According to Richter (Elementary Seismology, 1958) it was one of the first successful vertical motion seismometers. It is based on a spring-suspended mass that as it moves "alters an air gap between armature and pole pieces of a magnet, inducing EMF in coils wound round the pole pieces." Has anyone else on this list heard of these kinds of seismometers? Are they still in use today or have they been rendered obsolete? I believe the original owner was the USGS in Colorado somewhere... ****************************************************************************** John Hernlund E-mail: hernlund@....... WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Clark Wockner Subject: Re: event Date: Sat, 19 Jul 1997 23:30:53 -0700 Hello All A beautiful seismogram of the Guerrero event made it all the way to the seismic waste land of central Illinois. Everything worked as advertised and I am pleased as punch. I have sent it to Larry for posting in the psn file. Regards, Clark _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson Subject: Re: Variable Reluctance Seismometer Date: Sun, 20 Jul 1997 17:54:46 +1200 John, yes these were very popular and were used as a short period seismometer at all World Wide Standard Seismic Network Stations many still in use Dave PS was the air conditioner the final source of the vibrations or has that not yet been tracked down??? At 09:07 PM 7/19/97 -0700, you wrote: >Hello All, > I have found some literature on our seismometer finally (it was donated >and I didn't have much information about it). It is a variable reluctance >type seismometer designed by Hugo Benioff in 1930. According to Richter >(Elementary Seismology, 1958) it was one of the first successful vertical >motion seismometers. It is based on a spring-suspended mass that as it >moves "alters an air gap between armature and pole pieces of a magnet, >inducing EMF in coils wound round the pole pieces." > > Has anyone else on this list heard of these kinds of seismometers? >Are they still in use today or have they been rendered obsolete? I >believe the original owner was the USGS in Colorado somewhere... > >****************************************************************************** > > John Hernlund > E-mail: hernlund@....... > WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ > >****************************************************************************** > > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: John Hernlund Subject: Re: Variable Reluctance Seismometer Date: Sat, 19 Jul 1997 23:35:54 -0700 (MST) On Sun, 20 Jul 1997, David A Nelson wrote: > John, > yes these were very popular and were used as a short period > seismometer at all World Wide Standard Seismic Network Stations many > still in use > > Dave > > PS was the air conditioner the final source of the vibrations or has that > not yet been tracked down??? Yes, it sure was. I recorded some definite seismic events since then (the 6.2 this morning) and I am learning to tell the differences. The main problem is that the seismometer is inside of the building and it is mainly recording the building's response so that the frequencies don't vary a whole lot from about 2 Hz (probably the buildings natural frequency). I need to get it out of there and hopefully into the ground somewhere nice. The main problem is getting approval for all the wiring and stuff that will require (maybe I should look into a wireless setup?). ****************************************************************************** John Hernlund E-mail: hernlund@....... WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: Re: Variable Reluctance Seismometer Date: Sun, 20 Jul 1997 08:00:58 -0700 John I have been looking around myself for wireless transmittion possibilities. I have seen transievers, transmitters & receivers that transmit at 418 & 433 Mhz. I would like to find out more. They are reasonably priced(<$100), & compact. My knowledge of radio waves is limited. They appear to work up to about 600'. Abacom technologies is a source I have been curious about. (416-242-3120) No web page noted. Barry John Hernlund wrote: > I need to get it out of there and hopefully into the ground > somewhere nice. The main problem is getting approval for all the wiring > and stuff that will require (maybe I should look into a wireless setup?). > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Michael Chang Subject: The Inner Workings of the Earth Date: Sun, 20 Jul 1997 22:12:24 -0700 Some interesting reading from the American Scientist magazine. http://www.amsci.org/amsci/articles/95articles/Wysession-full.html Michael Chang, Montreal Canada _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson Subject: new station Date: Mon, 21 Jul 1997 16:36:09 +1200 hi all, well it has finally happened, one of my wish list items has been answered.... We have a new station is a remote but seismically active region.... Please extend a warm welcome to Tony Potenzo from the Big Island of Hawaii to the group he is yet another station using Larry's SDR and Winquake. It will be great to see events from that part of the world. chow Dave Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Ron Westfall Subject: Re: Contribution Date: Mon, 21 Jul 1997 10:08:34 -0700 I would be willing to contribute annually. Ron Westfall _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: John Hernlund Subject: Hall Effect Sensor Date: Mon, 21 Jul 1997 14:10:49 -0700 (MST) Hello All, I recall a while back somebody was inquiring about hall effect sensors. I was able to experiment with a hall effect sensor and I think it has a lot of potential. The idea is different than normal magnetic induction though, so it requires different design characteristics. It also takes all of the work away from the inertial mass, which can allow easy natural period measurements and independent damping. For anyone who isn't familiar with the hall effect, here is how it works: A) A conducting metal is placed in series with a circuit. B) The conducting metal is usually in the shape of a rectangular plate. C) Two probe wires are attached to the top and bottom of the rectangle. D) Here is a simple diagram: Probe wire | _______|________ | | >>>____________| |__________________>>>> Current Direction | | |______________| | | Probe wire D) Now if you provide a magnetic field that has a flux through the plate, the individual "charge carriers" experience a force that is: F = q(V X B) or F = qVB sin(theta) where theta is the angle the field makes with the plane of the rectangle vertically E) This force will deflect the charge carriers to the top or bottom of the plate, creating a potential difference between the two probe wires due to the charge build up. F) This voltage is then amplified like every other set up... Note: Of course the "qV" term above is inadequate for this situation, but it suffices to say that the term is constant provided that the current does not change through the conductor (DC). If you want, you can get F = I(L X B) = ILB sin(theta). Therefore since the potential difference is proportional to the force, it is also proportional to B sin(theta). Now you can see how this differs from normal magnetic induction, because the potential is no longer given in terms of the velocity. In other words, if you could vary the term sin(theta) in a seismometer proportional to the displacement of the inertial mass you now have a displacement seismometer. In practice this would be difficult to set up, but may be worthwhile... The other way is to vary B with respect to the displacement of the inertial mass. This would not be as easy as the previous suggestion to compute the actual displacement and velocity of the mass (B varies as 1/(r^2). Hope somebody finds this useful in their attempts to find newer methods of seismometry to use... ****************************************************************************** John Hernlund E-mail: hernlund@....... WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: JIM CRISTIANO Subject: Re: Wireless made Simple Date: Mon, 21 Jul 1997 17:16:20 -0700 barry lotz wrote: > > John > I have been looking around myself for wireless transmittion > possibilities. I have seen transievers, transmitters & receivers that > transmit at 418 & 433 Mhz. I would like to find out more. They are > reasonably priced(<$100), & compact. My knowledge of radio waves is > limited. They appear to work up to about 600'. Abacom technologies is a > source I have been curious about. (416-242-3120) No web page noted. > Barry > > John Hernlund wrote: > > > I need to get it out of there and hopefully into the ground > > somewhere nice. The main problem is getting approval for all the wiring > > and stuff that will require (maybe I should look into a wireless setup?). Barry and John, I saw an ad in Sensors Mag and got some info faxed to me from a company in Medford, Or. called Linx Technologies. They make small, low cost xmit and rcv modules that work out to 800'. They now have a web site with lots of info at linxtechnologies.com. The analog data signal is mono-polar, but that can be delt with. Regards, Jim cristiano@........... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: shammon1@............. Subject: Is that what you really wanted to say? Date: Mon, 21 Jul 1997 21:07:36 -0700 While the picture of the damaged house taken after the 1868 Hayward quake tells most of the store, I don't think the caption with the photo is exactly what the good people of Hayward had in mind when they put this WEB site together... http://www.physics.ucla.edu/~uhui/me/hayward.html Regards, Steve Hammond PSN San Jose, California _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson Subject: Re: Is that what you really wanted to say? Date: Tue, 22 Jul 1997 18:41:20 +1200 definately a bit raw not the sort of language that I would expose my kids to Dave At 09:07 PM 7/21/97 -0700, you wrote: >While the picture of the damaged house taken after the 1868 Hayward quake >tells most of the store, I don't think the caption with the photo is >exactly what the good people of Hayward had in mind when they put this >WEB site together... > >http://www.physics.ucla.edu/~uhui/me/hayward.html > > >Regards, > >Steve Hammond >PSN San Jose, California > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson Subject: winquake mag. calc's Date: Tue, 22 Jul 1997 18:55:26 +1200 Larry, something I have been meaning to ask for ages..... why does winquake not always give a mag calc. eg. as in Tony's Hawaiian posting of the Aleutians event. it is seen quite often on various event files posted to the list even on the occassional one of mine is it that we are not using Winquake properly or what ??? Cheers Dave Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Re: winquake mag. calc's Date: Tue, 22 Jul 1997 00:17:22 -0700 At 06:55 PM 7/22/97 +1200, Dave Nelson wrote: >Larry, > something I have been meaning to ask for ages..... > why does winquake not always give a mag calc. eg. as in Tony's >Hawaiian posting of the Aleutians event. > it is seen quite often on various event files posted to the list >even on the occassional one of mine is it that we are not using >Winquake properly or what ??? > These are usually new stations who have not set their Magnitude Correction Factor number yet. WinQuake needs this number to calculate ML and Ms magnitude. I started showing Ms calculation in the current beta release of WinQuake. The beta release also calculates Md. Md is only for local events and does not need the Magnitude Correction Factor number. Md uses the duration of the event rather then them max amplitude like ML or Ms. This is nice because it doesn't matter if your system saturates or not. I will be working on a new, more formal release of WinQuake. So if your have an older version without the Ms and Md calculations please wait a few days so I can get another release together. What I need to do is document all of the changes I have made. Since I HATE working on documentation I keep putting it off and adding more features, the fun part. Unfortunately I then have more documentation to do.... Anyway, I'll try and get it ready for release this weekend. This is one way I can repay all of the help I have gotten with the purchase of the mail sever and other expenses. So far I have received $435.00! One check was for $300.00, I won't name him, but thanks from all of use... I will send out the new total in a few days. Regards, Larry Cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "P,McCarty" Subject: Re: Variable Reluctance Seismometer Date: Tue, 22 Jul 1997 09:11:35 -0400 listserver@............. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: JIM CRISTIANO Subject: Re: Wireless made Simple Date: Tue, 22 Jul 1997 13:49:21 -0700 John Hernlund wrote: > > On Mon, 21 Jul 1997, JIM CRISTIANO wrote: > > Barry and John, > > > > I saw an ad in Sensors Mag and got some info faxed to me > > from a company in Medford, Or. called Linx Technologies. They make > > small, low cost xmit and rcv modules that work out to 800'. > > > > They now have a web site with lots of info at linxtechnologies.com. > > > > The analog data signal is mono-polar, but that can be delt with. > > Jim cristiano@........... > > Jim, > > I have been thinking more about the wireless stuff, but the "boss" > here is concerned about investing money and having to deal with radio > interference problems. Do you know how well these work? I really want > to have a good station here, so this is a big concern for me right now... John, I haven't tried the setup myself, but after reading the data sheets it looks like a good deal. It's a high performance, SAW-based FM/FSK analog/digital system. The analog output is 0-5V or the information can be sent in digital form (more complex setup, input-output). The current models run at 418mHZ. In August, they will have a 916mHZ txmit/rcv pair. For $44.50, it might be worth trying. Linx has tech help. I would worry about how far to separate the transmitter/antenna from the magnet/coil to avoid RF pickup. On another note, I've been working on a Hall Effect Sensor input, force balanced, vertical sensor. Using a small, rare-earth magnet, I can get a very sensitive linear output. Adios, Jim cristiano@........... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: John Hernlund Subject: Re: Wireless made Simple Date: Tue, 22 Jul 1997 15:42:12 -0700 (MST) On Tue, 22 Jul 1997, JIM CRISTIANO wrote: > I haven't tried the setup myself, but after reading the data sheets > it looks like a good deal. It's a high performance, SAW-based FM/FSK > analog/digital system. The analog output is 0-5V or the information > can be sent in digital form (more complex setup, input-output). Maybe I'd prefer the digital signal... > The current models run at 418mHZ. In August, they will have a 916mHZ > txmit/rcv pair. For $44.50, it might be worth trying. Linx has > tech help. I would worry about how far to separate the > transmitter/antenna > from the magnet/coil to avoid RF pickup. Definitely another thing to think about... > On another note, I've been working on a Hall Effect Sensor input, > force > balanced, vertical sensor. Using a small, rare-earth magnet, I can get > a very sensitive linear output. Yeah, the neat thing is that the output can be controlled by simply changing the current, and a neodymium magnet or something similar could surely give a good difference in signal per unit displacement (probably more than most transducers). I am curious, how did you set it up to get a linear response? I am sure that a linear response could be fairly approximated if it was far enough away from the magnetic source, but that would require a stronger magnet and most likely would only hold for small displacements... ****************************************************************************** John Hernlund E-mail: hernlund@....... WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Re: Wireless made Simple Date: Wed, 23 Jul 1997 01:16:02 -0700 At 03:42 PM 7/22/97 -0700, John Hernlund wrote: >On Tue, 22 Jul 1997, JIM CRISTIANO wrote: >> I haven't tried the setup myself, but after reading the data sheets >> it looks like a good deal. It's a high performance, SAW-based FM/FSK >> analog/digital system. The analog output is 0-5V or the information >> can be sent in digital form (more complex setup, input-output). > > Maybe I'd prefer the digital signal... I don't think so. This means you need an A/D converter at the sensor end and then convert the signal, at the receiving end, back to analog so it can be run into another A/D converter, your SDR system. That's a lot of electronics... What I would do is use the method that the USGS uses for the remote sensors around here. They use a voltage control oscillator, at the sensors end, that produces a tone that changes frequency as the signal changes from the sensor. At the receiver end you change the tone back into an analog signal that can then go into you A/D card. My telemetry board will do the demodulation and making the voltage controlled osc. is pretty easy using an Exar XR2206. It looks like the RF modules can pass an analog tone so they might work using this method and their RF link. The advantage with this method is it will work with any audio RF link or phone line. The disadvantage is the lost of dynamic range with all of this electronics between the sensor and your SDR system. Using the standard +-125 hz max. deviation that the USGS uses for their system, one can only get 10 to 11 bits of dynamic range. They use the narrow deviation so they can have up to 9 different sensors on one standard 5khz audio channel. This can be either a RF link or phone line. If you only want to monitor one sensor then you can increase the tone deviation and get a better dynamic range. Maybe down to 11 or 12 bits, I don't think one can get below that using this method. You might consider moving the SDR computer system next to the sensor but that brings up a bunch of other problems... > >> The current models run at 418mHZ. In August, they will have a 916mHZ >> txmit/rcv pair. For $44.50, it might be worth trying. Linx has >> tech help. I would worry about how far to separate the >> transmitter/antenna... The price is definitely right... -Larry Cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: JIM CRISTIANO Subject: Hall Sensor Date: Tue, 22 Jul 1997 21:46:50 -0700 John, I was using the Allegro part, then I got a Hall device from Honeywell/Microswitch. It has five times the sensitivity or 25mV/g. Both the Allegro and Honeywell/Microswitch data books show how to get linear/+ -0- - outputs. One is called a push-push magnet setup where two magnets are mounted with like poles facing each other and a gap in between. The Hall device is mounted in the gap. When the magnets are moved from center, the Hall output is linear both sides of the 0 gauss voltage. The axis of the magnet poles is perpendicular to the face of the device. The other way is called the slide-by where a bar magnet is mounted with the pole axis parallel with the device face. When the magnet is centered the output is 0 Gauss voltage. I am using the latter method, only I use a small rare-earth magnet disk 1/8" thick. With the short magnet is a short field that changes polarity in a small amount of space. This setup is so sensitive that it is difficult to center the magnet to the device face to establish a zero refference point. Sooooooo....... I think this setup would work well in a force-balanced system where it would zero itself. How do you spell goodbye in French? Jim cristiano@........... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: JIM CRISTIANO Subject: Re: Wireless made Simple Date: Wed, 23 Jul 1997 08:24:45 -0700 Larry Cochrane wrote: > > At 03:42 PM 7/22/97 -0700, John Hernlund wrote: > >On Tue, 22 Jul 1997, JIM CRISTIANO wrote: > >> I haven't tried the setup myself, but after reading the data sheets > >> it looks like a good deal. It's a high performance, SAW-based FM/FSK > >> analog/digital system. The analog output is 0-5V or the information > >> can be sent in digital form (more complex setup, input-output). > > > > Maybe I'd prefer the digital signal... > > I don't think so. This means you need an A/D converter at the sensor end > and then convert the signal, at the receiving end, back to analog so it can > be run into another A/D converter, your SDR system. That's a lot of > electronics... > I Agree, it would be double redundant(?). > What I would do is use the method that the USGS uses for the remote sensors > around here. They use a voltage control oscillator, at the sensors end, > that produces a tone that changes frequency as the signal changes from the > sensor. At the receiver end you change the tone back into an analog signal > that can then go into you A/D card. My telemetry board will do the > demodulation and making the voltage controlled osc. is pretty easy using > an Exar XR2206. It looks like the RF modules can pass an analog tone so > they might work using this method and their RF link. > > The advantage with this method is it will work with any audio RF link or > phone line. The disadvantage is the lost of dynamic range with all of this > electronics between the sensor and your SDR system. Using the standard > +-125 hz max. deviation that the USGS uses for their system, one can only > get 10 to 11 bits of dynamic range. They use the narrow deviation so they > can have up to 9 different sensors on one standard 5khz audio channel. This > can be either a RF link or phone line. If you only want to monitor one > sensor then you can increase the tone deviation and get a better dynamic > range. Maybe down to 11 or 12 bits, I don't think one can get below that > using this method. This txmit/rcv pair already is a audio tone frequency modulator/demodulator @....... What I would try would be to feed the data input of the txmit module with the output of a single supply pre-amp, adjusted for 2.5V output with 0V input from the coil. The output of the rcv module is a duplicate of the original signal from the pre-amp. This signal would be shifted to + - 0V by a dual supply opamp and then fed to the input of the low-pass filters on the filter/amp board. This could be done by referencing the input preamp to 2.5V. Jim cristiano@........... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: John Hernlund Subject: Re: Hall Sensor Date: Wed, 23 Jul 1997 13:51:04 -0700 (MST) Jim, That hall effect set-up sounds pretty nice. How much did the sensor you have cost? I may try to set up something for horizontal motion, as long as I can keep it fairly centered (I don't want it to require too much maintenance). ****************************************************************************** John Hernlund E-mail: hernlund@....... WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: JIM CRISTIANO Subject: Re: Hall Sensor Date: Wed, 23 Jul 1997 16:32:20 -0700 John Hernlund wrote: > > Jim, > That hall effect set-up sounds pretty nice. How much did the sensor > you have cost? I may try to set up something for horizontal motion, as > long as I can keep it fairly centered (I don't want it to require too > much maintenance). John, The parts I have are Honeywell/Microswitch SS94A1F. thier web page is honeywell.sensing.com. I called 1-800-537-6945 and requested 5 samples and a data book. If I remember right, they were pretty cheap if you have to buy any. The data book is a must have, lots of stuff in magnet interfacing and resulting performance graphs. Good luck, Jim cristiano@........... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Re: Wireless made Simple Date: Wed, 23 Jul 1997 20:57:20 -0700 At 08:24 AM 7/23/97 -0700, JIM CRISTIANO wrote: > This txmit/rcv pair already is a audio tone frequency modulator/demodulator > @....... Good point... Then the next question is how much dynamic range does the system have if you have good reception? > What I would try would be to feed the data input of the txmit > module with the output of a single supply pre-amp, adjusted for 2.5V >output with 0V input from the coil. The output of the rcv module is a >duplicate of the original signal from the pre-amp. This signal would be shifted >to + - 0V by a dual supply opamp and then fed to the input of the >low-pass filters on the filter/amp board. This could be done by referencing the > input preamp to 2.5V. That should work. I would add some low-pass filtering at the xmit end, but it may not be needed. -Larry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Charlie Rond Subject: Re: Is that what you really wanted to say? Date: Thu, 24 Jul 1997 06:46:24 -0500 Steve, >While the picture of the damaged house taken after the 1868 Hayward quake >tells most of the store, I don't think the caption with the photo is >exactly what the good people of Hayward had in mind when they put this >WEB site together... This webmaster may be weak on grammar and spelling but certainly not on picture captioning! Charlie Rond -\/\--Public Seismic Network-Memphis rond@................ (901) 360-0302 [ free BBS ] http://gandlf.ceri.memphis.edu/~rond http://gandlf.ceri.memphis.edu/~rond/psn _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: roger baker Subject: Basics of Instrumentation Date: Thu, 24 Jul 1997 10:26:05 -0500 (CDT) Friends, IMHO there is no better review of the essential basics of electronic instrumentation so clearly presented anywhere in the English language as chapter 15 of The Art of Electronics by P. Horowitz and W. Hill. This chapter, titled *Measurements and Signal Processing* deals with many of the questions and issues raised in this list. This 54 pages of information manages to not only review all the common transducers used as front end sensors, including magnet and coil velocity transducers, but also gives excellent front end circuits for stuff as demanding as nerve cell amplifiers, atomic clock standards, using satellite and radio time standards, lock-in and voltage to frequency conversion techniques and lots more. And its chock full of sage advice such as: *in practice, choose time/frequency transducers and measurements, rather than voltage resistance measurements, whenever possible.* So if you want to master the critical front end; the principles of getting from practically any sensor to a data stream with grace and style and low noise, even if you don't understand too much electronics, read this chapter. And the rest of the book is a classic too! For example chapter 9 is an excellent lesson on analog to digital conversion techniques, alternatives and tradeoffs. --Yours, Roger Baker _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert L Barns <75612.2635@..............> Subject: Basics of Instrumentation Date: Thu, 24 Jul 1997 11:36:26 -0400 Roger, I heartily agree with your recommending Horowitz & Hill. I have cited them in the past. Bob Barns _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: JIM CRISTIANO Subject: wireless Date: Thu, 24 Jul 1997 13:35:09 -0700 Howdy, What's that saying.......If it feels good it must be illegal? I talked to a tech at Linx, He says that transmitting audio information at those frequencies is illegal (Part 15, chaper 2, paragraph 105, sentence 3,285). He suggested using a Radio Shack FM audio transmitter and a FM radio reciever. Since Larry already has a demodulator board and it's pretty easy to modulate an oscillator, all one would need is a RF transmitter. Anyone know how the USGS does it? jim cristiano@........... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David Josephson Subject: Re: wireless Date: Thu, 24 Jul 1997 17:45:29 -0700 (PDT) On Thu, 24 Jul 1997, JIM CRISTIANO wrote: > Howdy, > > What's that saying.......If it feels good it must be illegal? > > I talked to a tech at Linx, He says that transmitting audio > information at those frequencies is illegal (Part 15, > chaper 2, paragraph 105, sentence 3,285). He suggested using > a Radio Shack FM audio transmitter and a FM radio reciever. I came to this thread late and have no idea what device you're talking about ... if it's the Linx 400 MHz units, he is snowing you with chapter and verse that does not exist. Part 15 of the FCC Rules (which is part of Title 47 of the Code of Federal Regulations) has no subdivisions other than "sections" which are stated as numbers after a decimal point, as in section 15.231, which is probably what he's talking about. You can't send continuous voice or data, only intermittent signals like alarms (and garage door opener signals, which is what this section was for. > > Since Larry already has a demodulator board and it's pretty > easy to modulate an oscillator, all one would need is a > RF transmitter. Anyone know how the USGS does it? USGS has custom-made telemetry transmitters, but they seem to be fairly straightforward. The seismograph signal frequency-modulates an oscillator which then FMs a radio carrier. The GS has the advantage of government frequency allocations, but non-profit experimenters have a lot of other frequencies that can be used, amateur radio for instance. The business band interstitial channels (12.5 kHz removed from the usual 25-kHz spaced frequencies 450-470 MHz) are also usable. If you use highly directional antennas you can get by with low power and not bother anyone. The source for transmitters is from crystal-controlled police and fire radios. In the 80's many of these were replaced with synthesized units, and now those are being replaced with trunked radio systems. This means that you can get a complete FCC approved receiver and transmitter for under $50, often under $20. The catch is in finding a good frequency, getting licensed for it and (as Ken Navarre and I have experienced recently) getting one of the old-reliable crystal manufacturers to make crystals on your desired frequency. With amateur radio it's a lot less formal as far as licensing goes but you need to pick a spot of the band where it won't bother anyone. But the hardware is quite available and nearly free. > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: John Hernlund Subject: Re: wireless Date: Fri, 25 Jul 1997 00:25:11 -0700 (MST) > I came to this thread late and have no idea what device you're talking > about ... if it's the Linx 400 MHz units, he is snowing you with chapter > and verse that does not exist. Part 15 of the FCC Rules (which is part of > Title 47 of the Code of Federal Regulations) has no subdivisions other > than "sections" which are stated as numbers after a decimal point, as in > section 15.231, which is probably what he's talking about. You can't send > continuous voice or data, only intermittent signals like alarms (and > garage door opener signals, which is what this section was for. But how intermittent is intermittent? We would probable want an open transmission all of the time. But like you said below, with a directional antenna nobody else would know the difference correct? > The source for transmitters is from crystal-controlled police and fire > radios. In the 80's many of these were replaced with synthesized units, > and now those are being replaced with trunked radio systems. This means that > you can get a complete FCC approved receiver and transmitter for under $50, > often under $20. The catch is in finding a good frequency, getting licensed > for it and (as Ken Navarre and I have experienced recently) getting one of > the old-reliable crystal manufacturers to make crystals on your desired > frequency. With amateur radio it's a lot less formal as far as licensing > goes but you need to pick a spot of the band where it won't bother anyone. > But the hardware is quite available and nearly free. Another catch I see is the power supply at the transmission end of the set up. A transmitter probably couldn't run very long on normal batteries right? Then there is the amplifier and everything else as well to manipulate the signal. The police transmitters I have used in the past require recharging quite often. This leads me to believe that perhaps an AC power line and AC/DC transformer would be required either way in this set up. My school district has a lot of old surplus FM radios right now (they are fairly powerful too), so maybe I can experiment with a couple and see what happens... I suppose I can be a guinea pig for some of this stuff, because I have the resources and the combined expertise of everybody here and at the school. Also, we are already liscensed to use several different frequencies. By the way, where could I find or how could I build a good directional transmitting and receiving antenna pair? ****************************************************************************** John Hernlund E-mail: hernlund@....... WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: junger@.......... (Jack Unger) Subject: Re: wireless Date: Fri, 25 Jul 1997 00:42:03 -0700 (PDT) > > On Thu, 24 Jul 1997, JIM CRISTIANO wrote: > > > Howdy, > > > > What's that saying.......If it feels good it must be illegal? > > > > I talked to a tech at Linx, He says that transmitting audio > > information at those frequencies is illegal (Part 15, > > chaper 2, paragraph 105, sentence 3,285). He suggested using > > a Radio Shack FM audio transmitter and a FM radio reciever. > > I came to this thread late and have no idea what device you're talking > about ... if it's the Linx 400 MHz units, he is snowing you with chapter > and verse that does not exist. Part 15 of the FCC Rules (which is part of > Title 47 of the Code of Federal Regulations) has no subdivisions other > than "sections" which are stated as numbers after a decimal point, as in > section 15.231, which is probably what he's talking about. You can't send > continuous voice or data, only intermittent signals like alarms (and > garage door opener signals, which is what this section was for. > > > > Since Larry already has a demodulator board and > it's pretty > easy to modulate an oscillator, all one would need is a > RF > transmitter. Anyone know how the USGS does it? > > USGS has custom-made telemetry transmitters, but they seem to be fairly > straightforward. The seismograph signal frequency-modulates an oscillator > which then FMs a radio carrier. The GS has the advantage of government > frequency allocations, but non-profit experimenters have a lot of other > frequencies that can be used, amateur radio for instance. The business band > interstitial channels (12.5 kHz removed from the usual 25-kHz spaced > frequencies 450-470 MHz) are also usable. If you use highly directional > antennas you can get by with low power and not bother anyone. > > The source for transmitters is from crystal-controlled police and fire > radios. In the 80's many of these were replaced with synthesized units, > and now those are being replaced with trunked radio systems. This means that > you can get a complete FCC approved receiver and transmitter for under $50, > often under $20. The catch is in finding a good frequency, getting licensed > for it and (as Ken Navarre and I have experienced recently) getting one of > the old-reliable crystal manufacturers to make crystals on your desired > frequency. With amateur radio it's a lot less formal as far as licensing > goes but you need to pick a spot of the band where it won't bother anyone. Let's be careful here, using amateur radio frequencies requires having an amateur radio license. After an individual has a license, yes, by all means pick a frequency that won't bother anyone. However, using an amateur radio frequency WITHOUT an amateur radio license is HIGHLY illegal, and not recommended! > But the hardware is quite available and nearly free. > > > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L > -- Advertisement - Since 1993 - Providing wireless LAN-to-LAN connectivity. Since 1995 - Providing High-Speed Wireless Internet Access. http://www.ask-wi.com Social Comment - A gun, in a moment of anger, turns a "law-abiding" citizen into a criminal. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: JIM CRISTIANO Subject: Re: wireless Date: Fri, 25 Jul 1997 08:04:44 -0700 David Josephson wrote: > > On Thu, 24 Jul 1997, JIM CRISTIANO wrote: > > > Howdy, > > > > What's that saying.......If it feels good it must be illegal? > > > > I talked to a tech at Linx, He says that transmitting audio > > information at those frequencies is illegal (Part 15, > > chaper 2, paragraph 105, sentence 3,285). He suggested using > > a Radio Shack FM audio transmitter and a FM radio reciever. > > I came to this thread late and have no idea what device you're talking > about ... if it's the Linx 400 MHz units, he is snowing you with chapter > and verse that does not exist. Part 15 of the FCC Rules (which is part of > Title 47 of the Code of Federal Regulations) has no subdivisions other > than "sections" which are stated as numbers after a decimal point, as in > section 15.231, which is probably what he's talking about. You can't send > continuous voice or data, only intermittent signals like alarms (and > garage door opener signals, which is what this section was for. All, He did say that you could not transmit continuous audio per part 15, but I took artistic, sarcastic license with the bracketed info. Jim cristiano@........... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: [Fwd: Lecture Announcement] Date: Fri, 25 Jul 1997 09:54:42 -0600 -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". Public Seismic Network (PSN): A Model for a New Relationship Between the Survey and Society Edward Cranswick USGS Golden Thursday 31 July 1997 10:00 AM 4th Floor Conference Room US Geological Survey 1711 Illinois St Golden -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". From: "Phil Giannini" Subject: Geophones Date: 25 Jul 1997 09:16:15 U REGARDING Geophones Hi To All, A few weeks ago there was a lot of talk on the list about geophones. Well, I now have my very own R.T. Clark and Mitcham catalogs and am dying to buy a geophone to experiment with. The problem is, I need a little input as to which model to buy. To a point the price is not that important as they all seem fairly cheap, so any input as to which type is the best model to use would be appreciated. There are some terms used in the discriptions of the units I don't understand. Some of the terms used are: "STRINGS", "MARSH", &"LAND". If any one could explain how these terms apply I would appreciate it. I assume "Marsh and Land" would be the type of ground they are to be used on. "Strings", I don't have a clue. Are geophones easy to setup (like leveling etc.) as compaired to say a Lehman type sensor? Are they temperature sensitive or sensitive to wind? Do they just sit on the ground or do they have to be buried? What is the power requirement, if any? See, I told you I needed some help here! My goal is to "maybe" use a geophone as one of the input channels of a portable recording setup I am putting together. The plan is to travel to locations where events happen fairly regularly in hopes of recording some events up close and personal. Because the equipment will be, for the most part, out-of-doors and will be assembled and disassembled often, it is important that it be quite forgiving and easy to set-up. Thanks in advance for any advice anyone may have. Phil SFN & SFZ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Lucas Haag Subject: Re: Geophones Date: Fri, 25 Jul 97 14:19:55 CDT To help answer your question on "Stings", "Marsh" , and "Land": Marsh & Land has a lot to do with the case they are in. (I assume) The marsh cases are more than likely waterproof. Srtings is what they call when multiple geophones are on a cable. Hope some of my stupid wisdom helps :-) Lucas Haag At 09:16 AM 7/25/97 U, you wrote: > REGARDING Geophones > >Hi To All, > A few weeks ago there was a lot of talk on the list about geophones. >Well, I now have my very own R.T. Clark and Mitcham catalogs and am dying to >buy a geophone to experiment with. The problem is, I need a little input as to >which model to buy. To a point the price is not that important as they all >seem fairly cheap, so any input as to which type is the best model to use >would be appreciated. > There are some terms used in the discriptions of the units I don't >understand. Some of the terms used are: "STRINGS", "MARSH", &"LAND". If any >one could explain how these terms apply I would appreciate it. I assume >"Marsh and Land" would be the type of ground they are to be used on. >"Strings", I don't have a clue. > Are geophones easy to setup (like leveling etc.) as compaired to say a >Lehman type sensor? Are they temperature sensitive or sensitive to wind? Do >they just sit on the ground or do they have to be buried? What is the power >requirement, if any? See, I told you I needed some help here! > > My goal is to "maybe" use a geophone as one of the input channels of a >portable recording setup I am putting together. The plan is to travel to >locations where events happen fairly regularly in hopes of recording some >events up close and personal. Because the equipment will be, for the most >part, out-of-doors and will be assembled and disassembled often, it is >important that it be quite forgiving and easy to set-up. > > Thanks in advance for any advice anyone may have. Phil SFN & SFZ > > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > ************************************************ Lucas Haag HCR 66 Box 25A Bartley, Nebraska 69020-9717 Email: lhaag@.............. World Wide Web: http://www.swnebr.net/~lhaag KC0BJB, Amateur Radio Tecnician Class License ************************************************ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David Josephson Subject: Re: wireless Date: Fri, 25 Jul 1997 12:31:39 -0700 (PDT) > > continuous voice or data, only intermittent signals like alarms (and > > garage door opener signals, which is what this section was for. > > But how intermittent is intermittent? We would probable want an open > transmission all of the time. But like you said below, with a > directional antenna nobody else would know the difference correct? No point in doing it illegally when there are legal ways to do it. Unlicensed devices under 15.231 are good for intermittent *control* operations, not for sending any sort of data. And besides, the allowable field strength gets you garage door opener sort of range, which is not what we want, I imagine. > Another catch I see is the power supply at the transmission end of the > set up. A transmitter probably couldn't run very long on normal batteries > right? Then there is the amplifier and everything else as well to > manipulate the signal. The police transmitters I have used in the past > require recharging quite often. This leads me to believe that perhaps an > AC power line and AC/DC transformer would be required either way in this > set up. My school district has a lot of old surplus FM radios right now Yes, or a small solar battery. I would concentrate on the portables like Motorola HT220, MT500, and MX, or very low power mobiles like Motorola PAC-RTs, GE vehicular repeaters, etc. All of these require less than an amp at 12 volts when transmitting a watt or so. > stuff, because I have the resources and the combined expertise of > everybody here and at the school. Also, we are already liscensed to use > several different frequencies. By the way, where could I find or how > could I build a good directional transmitting and receiving antenna pair? You are not likely to be licensed to use those frequencies for data transmission however. The Joe Carr books on antenna design are a good practical introduction, as is the ARRL VHF/UHF antenna manual. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David Josephson Subject: Re: wireless Date: Fri, 25 Jul 1997 12:39:27 -0700 (PDT) On Fri, 25 Jul 1997, Jack Unger wrote: > > frequency. With amateur radio it's a lot less formal as far as licensing > > goes but you need to pick a spot of the band where it won't bother anyone. > > Let's be careful here, using amateur radio frequencies > requires having an amateur radio license. > After an individual has a license, yes, by all means pick a > frequency that won't bother anyone. However, using an amateur radio > frequency WITHOUT an amateur radio license is HIGHLY illegal, and > not recommended! I'm sorry not to have been more specific, but of course a license is required. However with the current no-code licensing scheme that results in full amateur priveleges above 50 MHz, that shouldn't be a problem. And the procedure for picking a frequency is also not as off-hand as some might think. There are band plans for each of the amateur bands that determine, by regulation and/or regional custom, what sections of what bands are used for what services. With one exception (spread-spectrum systems above 900 MHz, which are expensive) all systems that give range more than a few hundred feet require some form of licensing, performance checks and/or frequency coordination. > Social Comment - A gun, in a moment of anger, turns a "law-abiding" citizen > into a criminal. Just what are you getting at, here? _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Martin Brewer" Subject: Chilean 'quakes 97/07/25 Date: Fri, 25 Jul 1997 17:46:53 -0300 Hello All, Bermuda recorded good traces for the Near Coast of Central Chile events: USGS; NEIC: 97/07/25 06:47:03 UTC 30.20S 71.77W Mag 5.6 07:34:29 UTC 30.60S 71.98W Mag 5.5 Although the epicentres are about 7,000km from Bermuda and the earthquakes were relatively small, they were almost due South of here so that the N-S sensor must have been in near optimum orientation to record the events. Did anyone else detect these tremors? Regards, Martin Brewer _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: JIM CRISTIANO Subject: remote site Date: Fri, 25 Jul 1997 10:21:17 -0700 John, How far away do you want to set up your sensor site? After all the fray about RF pros and cons, if you could live with cable, a 4-20mA current loop transmitter might be easier to setup. No remote site power supply, low sensitivity to RF noise and a one integrated circuit front end that can be potted for burial with a geophone. Jim cristiano@........... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Doug Crice Subject: Re: Geophones Date: Fri, 25 Jul 1997 16:15:58 -0700 Geophones 101 The basic geophone sensor is a cylinder about 1 inch diameter and 1 inch long. They are velocity transducers comprising a moving coil and magnet voltage generator. The output is typically 1/2 volt/inch/second. See photo of typical geophone at http://www.geospacecorp.com/hsj.htm The moving coil is a pendulum with a natural frequency normally specified as part of the description (e.g. 10 Hz vertical). They response is flat above the natural frequency and rolls of at 12 db/octave below the natural frequency. Because earthquakes are low frequency, buy the lowest frequency geophone you can afford, say 4.5 Hz. Geophones come in vertical or horizontal orientation, and will bang against the stops if operated in the wrong orientation. Horizontal geophones are often called "shear" or "shearwave" phones. Vertical geophones are so common they get no special recognition. When the natural frequency is around 1 Hz, the geophone might be called a seismometer. Geophones are designed to be placed by intellectually challenged individuals, who start by throwing them over the side of a truck or out of a helicopter. Thus, planting them is not particularly difficult. The basic sensor will usually be found in some sort of case, called land (for sticking in normal ground) or marsh (for sticking down in a muddy swamp). You can see pictures of typical cases at http://www.geospacecorp.com/geo_case.htm Once they are in the case, there is usually a spike on the bottom which is just stuck in the ground (that way, the planters can figure out which way is up). For a permanent installation, it's nice to bury them out of the wind. If you buy just the sensor elements, you can seal them up in plastic or wax. In petroleum exploration, geophones are usuall connected in a series-parallel arrangement, with the geophones separated some distance (like 20 phones at 10 ft intervals for example). This orientation emphasizes the desired signals (reflections from straight down hit all the phones at the same time) and filters surface waves and noise. Used geophones are often sold in strings of 6 or 12 or more. A single-phone string is a string with only one geophone. Strings are so common that even when it isn't a string, it's called a string. Because the natural frequency is going to be a little higher than you would like, the geophones will work better for local earthquakes and poorly for teleseisms. Even the new ones don't cost much, so buy one and try one. Geophones are easy to work with and easy to amplify until you see local noise. Some adventurous types have been known to put in frequency compensation networks to lower the frequency response. I suppose you could do it with digital filters too. Doug Crice _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: John Hernlund Subject: Re: remote site Date: Fri, 25 Jul 1997 16:57:30 -0700 (MST) On Fri, 25 Jul 1997, JIM CRISTIANO wrote: > How far away do you want to set up your sensor site? After all > the fray about RF pros and cons, if you could live with cable, > a 4-20mA current loop transmitter might be easier to setup. No > remote site power supply, low sensitivity to RF noise and a > one integrated circuit front end that can be potted for burial > with a geophone. I am not sure how far yet. Probably at the most 200 ft. from the building, but I am not using a geophone but a huge vertical variable reluctance seismometer... ****************************************************************************** John Hernlund E-mail: hernlund@....... WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Kees Verbeek Subject: Re: Chilean 'quakes 97/07/25 Date: Sat, 26 Jul 1997 02:45:55 +0200 (MET DST) > >Did anyone else detect these tremors? > >Regards, > >Martin Brewer > > Can see them over here in holland, but it's very poor, there's a lot of wind and storm these days so also a lot of disturbance . Reconstruct (temporary) my "old" "Bosch" to a electronic version and that delivers a lot more sensitivity greetings Kees Verbeek _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Martin Brewer" Subject: Re: Chilean 'quakes 97/07/25 Date: Fri, 25 Jul 1997 22:08:46 -0300 > From: Kees Verbeek > Subject: Re: Chilean 'quakes 97/07/25 > Date: Friday, July 25, 1997 9:45 PM > > > >Did anyone else detect these tremors? > > > >Martin Brewer > > > Can see them over here in holland, but it's very poor, there's a lot of wind > and storm these days so also a lot of disturbance . > Reconstruct (temporary) my "old" "Bosch" to a electronic version and that > delivers a lot more sensitivity > > greetings Kees Verbeek > Kees, Thank you for replying to my question. I am very impressed that you picked up the signal from the Chilean events so far away and despite the storms. Regards, Martin _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson Subject: Re: Geophones Date: Sat, 26 Jul 1997 17:57:56 +1200 Phil, Geophones are very easy to set up. no power requirements, most have up to 15 deg tolerance in how level they are, I have seen no temperature probs. so nothing like the problems encountered with LP units such as Lehmans. I have attached a very small gif image opf the way my geophones are housed. it is only 5kb so wont hurt for all to see. my units age buried in the ground so that the top cap of the housing is ~flush with ground level. The mass of lead in the bottom of the tube improves sensitivity to distant events very well I used 4 core screened data cable to feed the signals into the house to to preamps. I have used up to 30 metres (~100ft) between geophones and preamps, with no problems the only wind problems suffered are the vibrations from the trees being transmitted into the ground..... but that would affect any sensor Dave At 09:16 AM 7/25/97 U, you wrote: > REGARDING Geophones > >Hi To All, > Are geophones easy to setup (like leveling etc.) as compaired to say a >Lehman type sensor? Are they temperature sensitive or sensitive to wind? Do >they just sit on the ground or do they have to be buried? What is the power >requirement, if any? See, I told you I needed some help here! > Thanks in advance for any advice anyone may have. Phil SFN & SFZ Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari From: Charlie Rond Subject: Re: [Fwd: Lecture Announcement] Date: Sat, 26 Jul 1997 02:34:58 -0500 Edward, >Public Seismic Network (PSN): >A Model for a New Relationship >Between the Survey and Society Good work! Wish I could be there to hear you. Charlie Rond -\/\--Public Seismic Network-Memphis rond@................ (901) 360-0302 [ free BBS ] http://gandlf.ceri.memphis.edu/~rond http://gandlf.ceri.memphis.edu/~rond/psn _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Doug Crice Subject: Re: Geophones Date: Sat, 26 Jul 1997 06:46:30 -0700 David: I'm curious why you only have one horizontal element in your drawing? In theory you should be ready to record surface waves from any direction and a second sensor is realatively cheap. I'm skeptical about the lead. In exploration geophysics, we want the sensor to follow the ground motion exactly, which means that you either want to match the impedances or make it light but tightly attached so it will follow the ground motion exactly. Perhaps your improved teleseism response results from structural resonances at low frequencies. Normally, one would use a tube (without the lead) which has been well sealed in place with mud or grout. See my sensors at http://www.georadar.com/geophone.htm for a system that works temporarily. A sealed plastic pipe would work even better, but I would seal it with wax instead of polyurethane, then I could take it apart later. Doug Crice _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson Subject: Re: Geophones Date: Sun, 27 Jul 1997 03:17:41 +1200 gidday Doug, thanks for your thoughts a few replies sprinkled amongst yours...... At 06:46 AM 7/26/97 -0700, you wrote: >David: > >I'm curious why you only have one horizontal element in your drawing? In >theory you should be ready to record surface waves from any direction >and a second sensor is realatively cheap. the drawing was more for info I do have a 3 axis station. > >I'm skeptical about the lead. In exploration geophysics, we want the >sensor to follow the ground motion exactly, which means that you either >want to match the impedances or make it light but tightly attached so >it will follow the ground motion exactly. Perhaps your improved >teleseism response results from structural resonances at low >frequencies. oh believe me it really works !!! in exp seismo. you are only interested in signals travelling 5 - 10 km x down and x back up to the surface I have exp. with and without and for the distant events >>500 km it improves the system greatly.... the lead idea came from the Seismo. Obs in Wellington city where my first set of 3 sensors were purchased I have since purchased more from Geo-Space in the USA. My sensors are all 4.5 Hz I can record a Mb3.5 at 300km, a 4.5 up to 600 km, a 5.5 up to ~1000 km not too bad for a low cost, short per. unit..... without the extra mass you could cut 150 km or so off the above figures one day I will get my comm. LP seismom. up and running I need to pour a concrete pad for it to sit on and maybe then see the surfave waves from some of the big American events. (a project for this coming summer) > >Normally, one would use a tube (without the lead) which has been well >sealed in place with mud or grout. See my sensors at >http://www.georadar.com/geophone.htm for a system that works >temporarily. A sealed plastic pipe would work even better, but I would >seal it with wax instead of polyurethane, then I could take it apart >later. the good thing about the polyurethane resin is that unlike normal epoxy resin the former does not set hard and is very easily sliced with a sharp knife. When I worked for telecom I used gallons of it for filling up cable joints. I have also used good ol' plaster of paris to pot the seismometers in the tube ( not forgetting to use some sealer around the geophone terminals where the wires are soldered on).... after all... if the top and bottom of the tube are watertight ( I usually seal the topcap with a smear of silicone sealer) then the potting compound is there only to hold the geophones in place. Some of my geophones have now been housed this way outside in all kinds of weather, for up to 5 yrs without any failures. dave > >Doug Crice > > Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: John Hernlund Subject: Re: Geophones Date: Sat, 26 Jul 1997 13:34:03 -0700 (MST) Dave and Doug, I have been going over some seismograms from local stations of local events (yes, AZ has quakes quite often due to settling along the basin/range faults and volcanic activity up north, but it is rare for them to be above 3.0 or so). Another interesting phenomenon that can be tracked sometimes with sensitive systems here is the contraction and settling of the ground due to ground water removal. It would be interesting to set some sensitive geophones out near one of the stress points in this process (where bedrock pokes out of the ground or near the surface) and see what I could get... Anyhow, It seems that the longer period devices kind of went berserk with them, while the shorter period devices provided sharp P and S arrivals. In your experience with geophones, do you get very good readings of local events? What is the typical damping factor/ratio on a geophone that you use? It seems that for surveying geophones a high damping ratio would be used to prevent any continued oscillation so that first arrivals of various reflections could be plotted sharply in order to complete reflection surveys. ****************************************************************************** John Hernlund E-mail: hernlund@....... WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Doug Crice Subject: Re: Geophones Date: Sat, 26 Jul 1997 14:41:39 -0700 John: Exploration geophones are normally damped at 0.7 (sometimes a little less) with a resistor to get a relatively flat frequency response. Critical damping means you don't get any oscillations. The manufacturer's data sheets have curves for various combinations. Over damping cuts the response at the low ends and also lowers the output because the coil resistance (say 500 ohms) and the damping resistor make a voltage divider. I don't have any knowldege to answer why your long-period sensors don't like subsidence events, but if I were to venture a guess, I would say that the subsidence is creating tilt or displacement. Since your long period sensor may be acting as a displacement sensor or a tilt meter, that's why it has problems. Doug _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Dick Morgret Subject: Early quakes Date: Sun, 27 Jul 1997 16:05:07 -0700 Friends & others, Check out the Bible, Psalm 114, 1 to 8. for an interesting description of early quake detection. I suspect Moses parting the waters had a similar reason. Dick Morgret Hayward, Ca. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: PSN Donations Date: Mon, 28 Jul 1997 21:03:02 -0700 Greetings, As of today (7/28) I have received 24 checks for a grand total of $1150.00! Way more then I had expected. Anyway, thanks to everyone who helped out. I have been sending personal "thank you" notes as I receive your checks. There are a few checks that I can't match up to email address so I would like to thank them here. They are: John Griffin (John, your ccnet.com address bounced back), Andrew Berg and someone at Synergy Comp. in Murrieta Ca. Thanks guys! The money that has come in so far is over the cost of the email server ($600.00) so the rest of the money will go toward the monthly expenses to keep this system online and running. As I wrote before the monthly costs are around $150.00 ($105 to my ISP, $14.00 for the phone line and ~$30.00 to the power company). The extra money will make big dent in that expense. Again, and I can't say it enough times, thanks everyone... Regards, Larry Cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: New release of WinQuake. Date: Mon, 28 Jul 1997 23:07:45 -0700 Hi again, As promised I worked this weekend on the documentation for the new release of WinQuake. I have completed both the 16 bit (for Windows 3.1) and the 32 bit (Win95 and NT) releases. This version is 2.4 and the zip files are called wq16v24.zip (16 bit version) and wq32v24.zip (32 bit version). I have released version 2.4 at the following address: 32 bit version: ftp://ftp.drnet.com/users/psn/software/wq32v24.zip ftp://ftp.netcom.com/pub/co/cochrane/wq32v24.zip and ftp://psn.quake.net/software/wq32v24.zip 16 bit version: ftp://ftp.drnet.com/users/psn/software/wq16v24.zip ftp://ftp.netcom.com/pub/co/cochrane/wq16v24.zip and ftp://psn.quake.net/software/wq16v24.zip You should be able to set your web browser, or FTP program, to one of the above address. Please try and download the program using the drnet.com or netcom.com address first. This will help keep the load down on my 28k modem at the psn.quake.net address. Heres what's new in this release: WinQuake will now calculate Md and Ms magnitude. Md uses the duration of the event, rather then the maximum amplitude like ML, and is only useful for local events. Ms uses the maximum amplitude of the surface waves developed by shallow teleseismic events. The program now keeps a list of directories, under the File menu, used to view event files. The Great Circle Distance calculation dialog box now displays both the azimuth to the event and from the event to the station. The program will now integrate the data. The program can now place the P and S markers for you if the event location and time are known. The Open File dialog box now allows for multiple selected files. The Open, Add Report and Delete buttons will use this feature. The new feature that locates the P and S markers, if the events Lat/Long and origin time are known, is pretty neat. I got the idea from Robert Barns who asked that I calculate the P and S arrival times in the Great Circle Distance dialog box. Rather then display it in the dialog box, I figured that I could place the P and S markers at the calculate times, for the P and S waves, in the main event window. When you use this feature it shows how well (or bad) things are with the timing of the seismogram, errors in the stations Lat/Long, and the location and origin time published by the reporting agency of the event. I have been using it a lot... Anyway, if you run into any problems with the new release please let me know. Regards, Larry Cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Phil Giannini" Subject: Geophone Info Date: 29 Jul 1997 07:37:06 U REGARDING Geophone Info Hi Gang, I was out of town for a few days and just checked my E-mail. Thanks for all the great info on geophones. Now I am going to order a couple, hook 'em up and see what happens. If I get OK results I will be putting the files up for all to see. Thanks again for all the help, Phil SFN & SFZ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: John Hernlund Subject: Re: New release of WinQuake. Date: Tue, 29 Jul 1997 09:12:54 -0700 (MST) Hi Larry, I am going to download your new WQ version this weekend. I have a question about WQ: Is it possible to edit the start and end times of the file in Win Quake? There are times when I save too much from SDR, and would like to chop some time off the beginning and end (this would also allow me to cut out noise for a more accurate FFT of the event) without having to go back to SDR and do another save. ****************************************************************************** John Hernlund E-mail: hernlund@....... WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Dennis Leatart Subject: Re: PSN Donations Date: Tue, 29 Jul 1997 09:59:17 -0700 Larry! I am sorry but I lost your snail adress-- I've looked every-- could you please post it one more time-- please!! Others may need it also to send in donation!!! Thanks! -- _____ __ | \.-----.-----.-----.|__|.-----. | -- | -__| | || ||__ --| |_____/|_____|__|__|__|__||__||_____| _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: roger baker Subject: Magnetometry Date: Tue, 29 Jul 1997 12:49:44 -0500 (CDT) Friends, I realize that this is an earthquake list, but there is a good chance some of you are interested in magnetometry too, although I don't know if minute local fluctuations in the Earth's field has any correlation with quakes. Those who are interested in this topic might take note of the fact that it is relatively easy to measure small fluctuatations in the earth field with nothing much more sophisticated than a dangling magnet/mirror combination and that magnetic storms were detected this way long before the cause was known. The pre-WWII magnetic observatories in many countries could routinely monitor about one part in 50,000 fluctuation in the earth field this way. I have no idea of why they did so on such a large scale, except it was easy to do. The classic work in the field of terrestial magnetism is Chapman and Bartels's Geomagnetism, which observes in the 1940 Oxford edition: ....even to the high order of accuracy aimed at in geomagnetic measurements, the earths field is in general uniform throughout a space of some cubic meters round any point. For this reason, the resultant force (tending to move the mass center of any ordinary magnet ) is extremely small, less than one millionth of its weight; consequently the intensity of the field is usually measured by its rotary effect, that is the couple it exerts on a needle. The attempt is made to measure time-changes of the earths magnetic intensity F at any point with an accuracy of 1 gamma, or about one part in 50,000; this proportion is equivalent to 0.002 mm in a length of 10 cm , or to two seconds in a day. I have found that force feedback can be used to improve the linear response of the classic dangling magnet/mirror magnetometer in exactly the same way as it linearizes the performance of short period seismometers. I've got at least a half-assed version of such an instrument built. But if anyone should want to detect solar storms and the like, Larry's boards have lots of spare channels, and it doesn't take thousands or even hundreds of dollars to monitor fields and to set up a magnetic field station. Basically all you need is a magnet and mirror dangling in a rather sophisticated but still hackable enclosure. --Yours, Roger Baker _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson Subject: Re: New release of WinQuake. Date: Wed, 30 Jul 1997 12:21:30 +1200 very easy John, duoble click mouse button at a point prior to the P arrival whilst holding button down drag mouse pointer to the left just past where the signal drops bact to background noise (or where you want to stop) release mouse and result is a "zoomed in" view. then save file, checking the view only box in the File save dialog box. Presto all the wasted space befor and after the event is gone dave At 09:12 AM 7/29/97 -0700, you wrote: >Hi Larry, > I am going to download your new WQ version this weekend. I have a >question about WQ: Is it possible to edit the start and end times of the >file in Win Quake? There are times when I save too much from SDR, and >would like to chop some time off the beginning and end (this would also >allow me to cut out noise for a more accurate FFT of the event) without >having to go back to SDR and do another save. > >****************************************************************************** > > John Hernlund > E-mail: hernlund@....... > WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ > >****************************************************************************** > > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Re: PSN Donations - My Address Date: Tue, 29 Jul 1997 20:24:48 -0700 Dennis, my address is Larry Cochrane 24 Garden St. Redwood City, PSN -Larry At 09:59 AM 7/29/97 -0700, you wrote: >Larry! > >I am sorry but I lost your snail adress-- I've looked every-- could you >please post it one more time-- please!! Others may need it also to send >in donation!!! Thanks! >-- > _____ __ >| \.-----.-----.-----.|__|.-----. >| -- | -__| | || ||__ --| >|_____/|_____|__|__|__|__||__||_____| > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Dennis Leatart Subject: Re: Magnetometry Date: Wed, 30 Jul 1997 04:29:37 -0700 HI Roger!! Found reading your post with interest. I have constructed a simple magnetometer inside a sealed jar with a mirror. It is suspended on a pendulum and a laser hits the mirror and the reflected light is projected on a scale about 12 feet away. I can observe small changes on the scale or larger ones. I have heard that small displacements of magnetic fields may actually be precursors to nearby earthquakes and that further, small changes do occur during magnetic storms on the sun. Larger storms do disrupt radio communication and can actually cause "blackouts" in certain areas-- that's why they are monitored so often--especially preWW2 and during. My magnetometer was fashioned after a type explained in an earlier issue of Sky and Telescope magazine , but would like to know how it could be more closely monitored on my computer. -- _____ __ | \.-----.-----.-----.|__|.-----. | -- | -__| | || ||__ --| |_____/|_____|__|__|__|__||__||_____| _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Marnie Gannon Subject: ISAIAH site Date: Wed, 30 Jul 1997 09:51:45 -0700 Just a note to let anyone who hasn't found it yet... a great site: http://www-socal.wr.usgs.gov/given/review/review_index.html This is a southern California list, pretty current..most quakes show up within a half an hour.. It's a frames based table..if you click on the highlighted event number, it will bring up a screen with seismograms from the 15 closest stations with phase picks, then below that, the USGS notification message on quake size, location, etc..THEN..hypoinverse phase solutions and phase listing.. Amazing for an automated site which posts so quickly.. Marnie Gannon _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Karl Cunningham Subject: Data Polarity Date: Wed, 30 Jul 1997 13:35:11 -0700 Hi all -- Does anyone know of a convention for seismic data polarity? I'm not sure how much it really matters, but I'd like to at least try to get it right. For instance, if a N-S oriented seismometer senses a north-to-south motion of the earth's surface, should the data produced go more positive or more negative? And if a vertical seismometer senses a rising motion, should the data produced go more positive or more negative? Karl Cunningham La Mesa, CA. karlc@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: Data Polarity Date: Wed, 30 Jul 1997 14:43:25 -0600 Up is positive North is postive East is positive Karl Cunningham wrote: > > Hi all -- > > Does anyone know of a convention for seismic data polarity? I'm not sure > how much it really matters, but I'd like to at least try to get it right. > > For instance, if a N-S oriented seismometer senses a north-to-south motion > of the earth's surface, should the data produced go more positive or more > negative? > > And if a vertical seismometer senses a rising motion, should the data > produced go more positive or more negative? > > Karl Cunningham > La Mesa, CA. > karlc@....... > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: Data Polarity Date: Wed, 30 Jul 1997 14:51:16 -0600 -Karl After rereading your message, I realized my reply was ambiguous within the context. Down to Up, i.e., upward, is positive. South to North, i.e., towards the North, is postive. West to East, i.e., towards the East, is postive. I hope this is more clear. -Edward Karl Cunningham wrote: > > Hi all -- > > Does anyone know of a convention for seismic data polarity? I'm not sure > how much it really matters, but I'd like to at least try to get it right. > > For instance, if a N-S oriented seismometer senses a north-to-south motion > of the earth's surface, should the data produced go more positive or more > negative? > > And if a vertical seismometer senses a rising motion, should the data > produced go more positive or more negative? > > Karl Cunningham > La Mesa, CA. > karlc@....... > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: John Hernlund Subject: Re: Data Polarity Date: Wed, 30 Jul 1997 14:07:14 -0700 (MST) On Wed, 30 Jul 1997, Edward Cranswick wrote: > Down to Up, i.e., upward, is positive. > South to North, i.e., towards the North, is postive. > West to East, i.e., towards the East, is postive. This refers to ground motion, right? If you push the mass on your vertical seismometer down, it should register a positive voltage to indicate ground motion moving up relative to the mass. The same goes for the others, pushing your mass south should read positive and pushing the E-W westward should read positive From what I have read, such polarities are useful in determining the direction and motion of the fault relative to your station (i.e. whether a compression (positive first) or dilation (negative first) reaches your vertical seismometer for the first P-wave arrival. A compilation of this information from many stations around the fault after a quake can yield a good approximation of the direction of motion along the fault and the dimensions and orientation of the fault itself... ****************************************************************************** John Hernlund E-mail: hernlund@....... WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson Subject: Re: Data Polarity Date: Thu, 31 Jul 1997 11:59:30 +1200 At 02:07 PM 7/30/97 -0700, you wrote: >On Wed, 30 Jul 1997, Edward Cranswick wrote: >> Down to Up, i.e., upward, is positive. >> South to North, i.e., towards the North, is postive. >> West to East, i.e., towards the East, is postive. > > This refers to ground motion, right? refers to the movement of the pen on the paper and once you have all 3 axis correct you can then use this system below to work out direction LOCATING DIRECTION FROM WHICH TREMOR HAS COME DILATION QUAKE THE QUAKE IS DILATIONAL IF 1ST MOTION OF P WAVE IS TO THE RIGHT ON VERTICAL THE TRACE N/S TRACE 1ST MOTION TO LEFT .... P WAVE FROM SOUTH 1ST MOTION TO RIGHT .... P WAVE FROM NORTH E/W TRACE 1ST MOTION TO LEFT .... P WAVE FROM EAST 1ST MOTION TO RIGHT .... P WAVE FROM WEST COMPRESSION QUAKE THE QUAKE IS COMPRESSIONAL IF 1ST MOTION OF P WAVE IS TO THE LEFT ON THE VERTICAL TRACE N/S TRACE 1ST MOTION TO LEFT .... P WAVE FROM NORTH 1ST MOTION TO RIGHT .... P WAVE FROM SOUTH E/W TRACE 1ST MOTION TO LEFT .... P WAVE FROM WEST 1ST MOTION TO RIGHT .... P WAVE FROM EAST Cheers Dave Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: Data Polarity Date: Wed, 30 Jul 1997 18:44:45 -0600 Rereading my remarks about ground motion and some of the confusion they have engendered, I will say more. Ground Motion: Down to Up, i.e., upward, is positive. Ground Motion: South to North, i.e., towards the North, is postive. Ground Motion: West to East, i.e., towards the East, is postive. The above is a convention we use here at our USGS group in Golden, CO, that chases earthquakes. The important thing is that the motion of the ground in one linear direction is ultimately represented by some kind of wiggly line on paper or a screen (computer, CRT, etc.), and as long as one knows that when the line moves up or down, the ground moves back and forth correspondingly, then one is getting started in using one's instrument to find out what the Earth is doing. -Edward John Hernlund wrote: > > On Wed, 30 Jul 1997, Edward Cranswick wrote: > > Down to Up, i.e., upward, is positive. > > South to North, i.e., towards the North, is postive. > > West to East, i.e., towards the East, is postive. > > This refers to ground motion, right? If you push the mass on your > vertical seismometer down, it should register a positive voltage to > indicate ground motion moving up relative to the mass. The same goes for > the others, pushing your mass south should read positive and pushing the > E-W westward should read positive > > From what I have read, such polarities are useful in determining the > direction and motion of the fault relative to your station (i.e. whether > a compression (positive first) or dilation (negative first) reaches your > vertical seismometer for the first P-wave arrival. A compilation of this > information from many stations around the fault after a quake can yield a > good approximation of the direction of motion along the fault and the > dimensions and orientation of the fault itself... > > ****************************************************************************** > > John Hernlund > E-mail: hernlund@....... > WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ > > ****************************************************************************** > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: [Fwd: Lecture Announcement] Date: Wed, 30 Jul 1997 19:00:25 -0600 PSN Members- Tomorrow I will be giving a one-hour lecture to people in my office about the PSN (see below). I will showing some PSN websites on-line and my email will be on-line because I want to emphasize the interactive aspect of the PSN on the Web. If you send me some short short email messages during the lecture, I will try to read them to the audience. Please send remarks addessed to professional seismologists who might be not fully cognizant of the potentialities of transmitting information simultaneously via the Earth, i.e., seismic waves, and the Web. The lecture will be at 16:00-17:00 31 August 1997 UTC (10:00-11:00 MDT North America). I probably won't have time to respond during the lecture, maybe one or two token replies, but it should be fun (Oprah, eat your heart out). -Edward PS. Maybe there will be a large earthquake. Larry Cochrane wrote: > > Hi Edward, > > Wish I could be there... Anyway of recording it, either audio or video, so > we can share it with the PSN members who can't make it? > > -Larry > > > At 09:54 AM 7/25/97 -0600, you wrote: > >-- > >Edward Cranswick Tel: 303-273-8609 > >US Geological Survey, MS 966 Fax: 303-273-8600 > >PO Box 25046, Federal Center cranswick@........ > >Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". > >Message-ID: <33D79F29.7081@........> > >Date: Thu, 24 Jul 1997 12:30:01 -0600 > >From: Edward Cranswick > >Organization: US Geological Survey, Golden, CO > >X-Mailer: Mozilla 3.01Gold (WinNT; I) > >MIME-Version: 1.0 > >To: geo_haz_team@.................. > >Subject: Lecture Announcement > >Content-Type: text/plain; charset=us-ascii > >Content-Transfer-Encoding: 7bit > > > >Public Seismic Network (PSN): > >A Model for a New Relationship > >Between the Survey and Society > > > >Edward Cranswick > >USGS Golden > > > >Thursday > >31 July 1997 > >10:00 AM > > > >4th Floor Conference Room > >US Geological Survey > >1711 Illinois St > >Golden > > > >-- > >Edward Cranswick Tel: 303-273-8609 > >US Geological Survey, MS 966 Fax: 303-273-8600 > >PO Box 25046, Federal Center cranswick@........ > >Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". > > -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: Re: New release of WinQuake. Date: Wed, 30 Jul 1997 17:30:36 -0700 Hi John I asked Larry the same question a few days ago. It seems that when you save a file in the zoomed condition there is a box indicating whether it is the viewed screen or not that you wish to save. I didn't mean to answer for Larry but I was going to ask the following question also. Talking about time: Larry- is there a way to change the record time in case ones clock is off? Barry John Hernlund wrote: > > Hi Larry, > I am going to download your new WQ version this weekend. I have a > question about WQ: Is it possible to edit the start and end times of the > file in Win Quake? There are times when I save too much from SDR, and > would like to chop some time off the beginning and end (this would also > allow me to cut out noise for a more accurate FFT of the event) without > having to go back to SDR and do another save. > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Re: New release of WinQuake. Date: Wed, 30 Jul 1997 21:52:17 -0700 At 05:30 PM 7/30/97 -0700, Barry Lotz wrote: >Hi John > I asked Larry the same question a few days ago. It seems that when >you save a file in the zoomed condition there is a box indicating >whether it is the viewed screen or not that you wish to save. I didn't >mean to answer for Larry but I was going to ask the following question >also. Looks like I need to make a FAQ for WinQuake... > Talking about time: Larry- is there a way to change the record time >in case ones clock is off? Yes, with WinQuake version 2.3 (maybe 2.2, I don't remember) or later you can change the time of the event file. It's under the File/Time Correction menu item. You can enter a positive or negative number of whole seconds that will be added or subtracted to the start/end time of the event file. -Larry Cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Charlie Rond Subject: Re: [Fwd: Lecture Announcement] Date: Thu, 31 Jul 1997 02:01:20 -0500 Edward, > Tomorrow I will be giving a one-hour lecture to people in my office >about the PSN (see below). Good luck today! We are all behind you and wish we could be there in more than spirit. You remind me I need to send a notice of mine. Charlie Rond -\/\--Public Seismic Network-Memphis rond@................ (901) 360-0302 [ free BBS ] http://gandlf.ceri.memphis.edu/~rond http://gandlf.ceri.memphis.edu/~rond/psn _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Charlie Rond Subject: Natural Hazards Workshop Date: Thu, 31 Jul 1997 02:57:02 -0500 PSN Members- Through CERI (Center for Earthquake Research and Information - University of Memphis) I was invited to present a poster session on PSN, give a short paper and appear on a panel at the recent Natural Hazards Workshop in Denver. The panel dealt with Community Based and Grassroots Organizations, and I tried to show that we were an effective and prime example. From a small group of highly dedicated and motivated individuals we've become a worldwide network gathering scientific data, helping one another and encouraging others to join us. My poster used mostly material from the Web and included several of your Web pages, Larry Cochrane's Lehman photos, Dave Nelson's map, Pete Rowe's amp schematic, etc. (I guess it's a little late to ask for permission to use them :-) In case your ears were tingling, I gave much credit to Edward Cranswick, and John Lahr (and Charles Richter) for concept; Steve Hammond, Ted Blank, Pete Rowe, Jerry and Dorothy Darby for actualization; Dave Nelson for his map, Larry Cochrane for lifting us to a new plateau, and many others. Thanks to CERI, we got some good exposure, educated some folks and startled some others who wanted to know where we get "all our funding." It might have looked like I was standing there "alone" but I made it clear I wasn't, and I felt the presence with me of all of you. (Sorry, I couldn't save you some barbecue and beer :-) Charlie Rond -\/\--Public Seismic Network-Memphis rond@................ (901) 360-0302 [ free BBS ] http://gandlf.ceri.memphis.edu/~rond http://gandlf.ceri.memphis.edu/~rond/psn _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Mike Stickney Subject: Re: Data Polarity Date: Thu, 31 Jul 97 08:09:34 MDT Karl: Back in the day of paper seismograms, standard instruments had positive deflections in the up, north, and east directions. Negative deflections were in the down, south, and west directions. -Mike Stickney Montana Bureau of Mines and Geology Butte, MT 59701 =========================================== At 01:35 PM 7/30/97 -0700, you wrote: >Hi all -- > >Does anyone know of a convention for seismic data polarity? I'm not sure >how much it really matters, but I'd like to at least try to get it right. > >For instance, if a N-S oriented seismometer senses a north-to-south motion >of the earth's surface, should the data produced go more positive or more >negative? > >And if a vertical seismometer senses a rising motion, should the data >produced go more positive or more negative? > > >Karl Cunningham >La Mesa, CA. >karlc@....... > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert L Barns <75612.2635@..............> Subject: Bear-dst, etc. Date: Thu, 31 Jul 1997 10:32:59 -0400 Hi gang, what's shakin' ? (Darn little here recently) Thanks to Roger Baker for suggesting the book on geomagnetism. I have requested a loan from the library. I'm still trying to buy "Quantitative Seismology" by Aki & Richards. = Any suggestions? The latest enhancements to WINQUAKE are neat. Rush right out and buy one! Larry has made my BASIC prog. BEAR-DST.BAS available in his archives. = Just go to psn.quake.net/software.html and look in 'Other Files'. = BEAR-DST.ZIP is 3.9k (a really cheap download) and contains the prog. and= a description of its input and output. The new WINQUAKE preempts one use o= f the prog. but I still find it useful to predict where to look for weak signals and how strong they might be. Briefly, here is what the prog. does. (More details are given in the write-up included in the . ZIP file.) The prog. outputs (among other things) predicted times for P, S and LQ for your location. These predictions are less accurate than Larry's (in WINQUAKE) since I only approximated the JB tables. The relative signal strength uncorrected and= corrected for azimuth are output. It probably won't work for nearby events, say closer than 100 miles. Bob Barns _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: Natural Hazards Workshop Date: Thu, 31 Jul 1997 08:55:49 -0600 Charlie- Sounds like you have done a good job of spreading the wealth, or rather, gospel. I am glad that you were invited to the Natural Hazards workshop but I am very sorry that I did not get a chance to see you while you were out here. Thank you very much for posting this message in time for my presentation. -Edward Charlie Rond wrote: > > PSN Members- > > Through CERI (Center for Earthquake Research and Information - University of > Memphis) I was invited to present a poster session on PSN, give a short > paper and appear on a panel at the recent Natural Hazards Workshop in > Denver. The panel dealt with Community Based and Grassroots Organizations, > and I tried to show that we were an effective and prime example. From a > small group of highly dedicated and motivated individuals we've become a > worldwide network gathering scientific data, helping one another and > encouraging others to join us. > > My poster used mostly material from the Web and included several of your Web > pages, Larry Cochrane's Lehman photos, Dave Nelson's map, Pete Rowe's amp > schematic, etc. (I guess it's a little late to ask for permission to use > them :-) > > In case your ears were tingling, I gave much credit to Edward Cranswick, and > John Lahr (and Charles Richter) for concept; Steve Hammond, Ted Blank, Pete > Rowe, Jerry and Dorothy Darby for actualization; Dave Nelson for his map, > Larry Cochrane for lifting us to a new plateau, and many others. > > Thanks to CERI, we got some good exposure, educated some folks and startled > some others who wanted to know where we get "all our funding." > > It might have looked like I was standing there "alone" but I made it clear I > wasn't, and I felt the presence with me of all of you. (Sorry, I couldn't > save you some barbecue and beer :-) > > Charlie Rond -\/\--Public Seismic Network-Memphis > rond@................ (901) 360-0302 [ free BBS ] > http://gandlf.ceri.memphis.edu/~rond http://gandlf.ceri.memphis.edu/~rond/psn > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Charlie Rond Subject: Re: Natural Hazards Workshop Date: Thu, 31 Jul 1997 11:28:27 -0500 Edward, > Sounds like you have done a good job of spreading the wealth, or >rather, gospel. I am glad that you were invited to the Natural Hazards >workshop but I am very sorry that I did not get a chance to see you >while you were out here. Thank you very much for posting this message >in time for my presentation. I was sorry we could not get together during the workshop, but I wanted to make sure you and the other PSN folks knew we were out there telling the story. Since I have widely touted you as the "father" of the PSN, I'm wondering if you shouldn't consider having a DNA test to prevent the kind of megabuck extortion that Cosby and others have had to contend with? :-) On the serious side, the capability of posting questions and opening discussion on the PSN listserv has been invaluable to us. Near-immediate access to professionals and expert scientific discussion - as well as the large "pool" of talent, expertise and interest now on the Internet have brought us a long way from the days of the BBS repositories. We're grateful to Larry Cochrane for establishing the PSN listserv, but also to you and the many others who are quickly giving us answers and "educating" us online. Good luck with your program.. Charlie Rond -\/\--Public Seismic Network-Memphis rond@................ (901) 360-0302 [ free BBS ] http://gandlf.ceri.memphis.edu/~rond http://gandlf.ceri.memphis.edu/~rond/psn _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Steve Hammond Subject: Request for URL's Date: Fri, 01 Aug 1997 15:19:46 -0700 Hi-- I am in the process of setting up the PSN San Jose web page. I'll announce the URL in a week or two. Just to get it going, I have taken a lot of stuff from the other PSN web sites. Once it is active, I'll start tailoring more to its own identity which I hope will be dedicated to the construction of Lehman seismographs. Part of this will be a collection of pictures showing home built seismographs. If you have a Lehman seismograph and a picture of it on the WWW I would like to add a pointer to your URL. If you want to mail me a picture of your unit so I can scan it drop me a note. Regards, Steve Hammond _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: "Feedback" Date: Fri, 01 Aug 1997 18:12:36 -0700 Hi In working with my force-balance sensor I am puzzled by the feedback loop. It is basically a resistor in series with the coil. Current in the coil with adjacent magnet produce the restoring force. I have a capacitor in parallel with the resistor to supposedly prevent oscillations. The series resistor is 30k, the parallel capacitor is 6uf and the coil has a resistance of 8+k (large # of 40 ga wire). I haven't tried many combinations of component values but I seem to be getting oscillations which I attribute to electronic component values rather than sensor oscillations. Is there a a way to calculate component appropriate values so I can increase my gain above the level it is currently at. The damping seems appropriate(about 0.7) Barry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Charlie Rond Subject: Re: Request for URL's Date: Sat, 02 Aug 1997 00:05:30 -0500 Steve, >Hi-- I am in the process of setting up the PSN San Jose web page. I'll >announce the URL in a week or two. Just to get it going, I have taken a >lot of stuff from the other PSN web sites. Once it is active, I'll >start tailoring more to its own identity which I hope will be dedicated >to the construction of Lehman seismographs. Part of this will be a >collection of pictures showing home built seismographs. If you have a >Lehman seismograph and a picture of it on the WWW I would like to add a >pointer to your URL. If you want to mail me a picture of your unit so I >can scan it drop me a note. That's great news. Do you want just pictures of the hardware or with people who built them, (school students), etc. Charlie Rond -\/\--Public Seismic Network-Memphis rond@................ (901) 360-0302 [ free BBS ] http://gandlf.ceri.memphis.edu/~rond http://gandlf.ceri.memphis.edu/~rond/psn _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: shammon1@............. Subject: Re: Request for URL's Date: Sat, 02 Aug 1997 00:44:11 -0700 Charlie Rond wrote: >to the construction of Lehman seismographs. Part of this will be a > >collection of pictures showing home built seismographs. If you have a > >Lehman seismograph and a picture of it on the WWW I would like to add a > >pointer to your URL. If you want to mail me a picture of your unit so I > >can scan it drop me a note. > > That's great news. Do you want just pictures of the hardware or with people > who built them, (school students), etc. > > Charlie Rond -\/\--Public Seismic Network-Memphis > Pictures of people with seismographs would be kind of nice. I'm planning a page called "The PSN Wall," a section of names schools and museums that PSN folks have helped during the years. Got a picture? Helped a school or museum? please drop me a note with a brief description so I can add it to the PSN Wall. And YES, I would like pictures of people, school students, and seismographs. Regards, Steve Hammond _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Karl Cunningham Subject: Re: "Feedback" Date: Sat, 02 Aug 1997 09:53:50 -0700 Hello Barry -- All else being equal, the force generated by the coil-magnet combination is proportional to the current through the coil. In your case you have a fair amount of dc resistance in the coil to limit current anyway. Adding resistance in series reduces the current even more and thereby reduces the gain around the feedback loop. Paralleling a capacitor across that resistor increases the current in the coil at higher frequencies and helps to stabilize the loop. What frequency are the oscillations you see? If it is in the range of a 1 Hz to 30Hz, be suspicious of mechanical resonances. I've had a lot of trouble with such things. They change the phase delay around the feedback loop and make it unstable. If you turn up the gain until it oscillates, can you see any physical movement in anything that is not supposed to move? Try momentarily increasing the gain to make it oscillate, then reduce it again and watch how fast the oscillation dies out. Then change things (stiffen some mechanical part or change some electronic component) and see if the oscillation dies out more quickly. Keep fiddling with this to try to get the oscillation to die out as quickly as you can. You'll probably be able to use a higher gain when you're done. As far as calculating component values, if it were strictly an electronic circuit I'd say it could be done fairly easily. But since the feedback loop includes mechanical components, it becomes much more difficult (but not impossible). Given that difficulty, I suspect it is easier to do it be trial and error. Do you have a schematic and/or mechanical diagrams you could send me? I'd be happy to look at it and give any suggestions that come to mind. Karl Cunningham La Mesa, CA. PSN Station #40 karlc@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: John Hernlund Subject: Geotech address Date: Sat, 02 Aug 1997 18:01:14 -0700 (MST) Hi All, Does anybody here have an address for geotech? I need to send for some information on our seismometer. ****************************************************************************** John Hernlund E-mail: hernlund@....... WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: sgazdik@........... (Sam Gazdik) Subject: Re: Geotech address Date: Sun, 3 Aug 97 17:04:20 PDT John - You can find Geotech at the following: Teledyne Brown Engineering - Geotech Instruments 10755 Sanden Drive Dallas, Texas 75238-1366 Contact person: Tom Trosper 214-343-7638 FAX - 214-343-4400 If this is regards to the "giant benioff sensor" that has recently been referred to in past messages " variable reluctance seismometer" they won't have anything on it. The closest you will find is the data in the old " Operation & Maintainance Manual - World Wide Seismograph System, Model 10700" under the seusmometer section - Model 1051 and 1101 ( Model 1051 - vertical). the same sensor was first manufactured by the Fred C. Hanson Co., Pasadena,Ca. and are the predecessor to the Geotech units. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Re: New WINQUAKE Date: Sun, 03 Aug 1997 20:17:25 -0700 Hi Bob and others, At 10:32 AM 7/31/97 -0400, Robert Barns wrote: >Larry, > Great stuff in the new WINQUAKE! > I found one sl. strange thing. Do LOC and see, for example, 0:30:23.0 >for ORG. I then zoom a small region around the P & S. Then do PS to get >the markers. Then do LOC to see the predicted P & S positions and look at >ORG, e.g. 0:30:23.0. Then RST back to the whole plot. ORG is now shown as >0:30:09.5. Do LOC again and see 0:30:23.0. Where did that 0:30:09.5 come >from? That's because you don't have the Lock P and S Markers (Under the Calculate menu item) on. See below... > I don't understand some of your HELP:1."Lock P-S Markers Locks tha P & S >markers to the X scale time." What is this? When this option is on, the P and S markers are locked to the time where you, or the LOC feature, placed them. If you zoom in or out they will stay at the same point in time on the seismogram. When this option is off the P and S markers will stay on the screen as you move around in the seismogram. > 2. "Restore P-S Picks Moves the P and S marks to the location saved in >the event file header information". Is this the info. that is saved by >"Save P-S Picks"? Yes. > I suggest that "Save P-S Picks" should be the default rather than having >to select that each time. I'm not sure about that... Maybe what I can do is make an option to enable the saving of the Picks on closing of an event file. > You have said several times that your S-G works better than your Lehman. >In what ways is it better and why the better performance? Suggest that >this explanation should be sent to the net, not just to me. >Bob Barns I like the SG sensors for several reasons: It has a smaller footprint then a long period Lehman. This makes it easier to thermally isolate etc. It is less susceptible to problems of the ground tilting that plagues some Lehmans. I constantly have to check my Lehman to make sure that it is centered near the pickup coil. Whenever it rains I have to re center it, sometimes twice a day. Part of the problem is my Lehman is sitting on top of a old wood floor. I'm sure part of the problem is do to humidity changes. Despite its smaller size, and do to the integration of the displacement pickup, it has an excellent low end frequency response. It really does a great job of picking up the very low frequency Love and Rayleigh waves on teleseismic events. Anther advantage, and also a disadvantage, is it's lack of high frequency response. Do to the integrator and displacement type of pickup there is not much frequency response above 1 - 2hz. Is is great for chasing teleseismic events even if you are near a lot of local ground noise, like I do. Since it's not picking up as much local ground noise you can increase the overall gain of the system. I found that making the SG sensor a little easier then the Lehman. The disadvantages are. For local events the lack of high end frequency response shows up in the seismograms. A Lehman, with a standard coil/magnet pickup and a 10 hz low pass filter produces much nicer looking seismograms. One way around this is too have two output ports from the sensor. One is the low frequency output of the integrator and another output that bypass the integrator. The "high frequency" output port still does not have the high end frequency response of a Lehman because the pickup uses displacement, not velocity. The SG sensor, do to its low frequency response, needs better thermal and draft protection. If you look at the photos of my SG sensor (at http://psn.quake.net/sgsensor.html) you will see the that box that covers the sensor is filled with foam rubber. This is need to keep internal air oscillations from happening. The SG sensor has more electronics then the Lehman. A simple low noise amp and filter is all that is need for a Lehman. The SG electronics is a little bit more complex do to it's electronic feedback for dampening. I think that the SG sensors is a AC coupled force balanced accelerometer, if there is such a thing. Regards, Larry Cochrane Redwood City,PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Charles R. Patton" Subject: Re: "Feedback" Date: Mon, 04 Aug 1997 09:04:13 -0700 (I'm sending this from work since it appears it didn't go through from home. So if it's resent, my apologies.) Barry, I'm a great believer in the "put your finger on it approach", whether it be electronic or electrical. If it's electronic oscillation, generally you'll see the oscillation frequency change, or damp out when you touch the offending area. This generally is good for finding RF oscillations and fast glitches due to coupling, too much gain, improperly compensated op-amps, in what is supposed to be a much lower frequency circuit. This is where the "ship a scope probe with it" comes from. The moment you probe such circuits the 10 to 15 pF in parallel with the 10M of the probe will fix the circuit. If you selectively touch the mechanical areas, you should be able to do roughly the same thing. If your finger is too "heavy" use a piece of vinyl or rubber tubing to touch with. If its touching the anti-node, the damping will change drastically, and it will probably be very apparent what is vibrating or oscillating. Charles R. Patton patton@......... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: Re: "Feedback" Date: Mon, 04 Aug 1997 20:35:20 -0700 Karl & Charles Thanks for the input. I needed to be reminded to remove variables one at a time to see what happens. When I fixed the sensor I got a FFT with a gradually decreasing amplitude with frequency increase to about 0 @ 10 hz. I haven't figured out the slope but it appears like a single pole LP. With the sensor fixed and the feedback coil disconnected I got about the same. With the system intact I got what appears to be a bandpass filter response centered @ about 1 hz. Isn't a cap in series with a coil just that? Maybe it's doing what it's supposed to and I need to adjust the frequency of the peak to what I want. ?? The tinkering continues. I guess this is what it's all about. There will always be earthquakes and different types of sensors to play with. Barry Charles R. Patton wrote: > Barry, > I'm a great believer in the "put your finger on it approach", > whether > it be electronic or electrical. If it's electronic oscillation, > generally you'll see the oscillation frequency change, or damp out when > you touch the offending area. This generally is good for finding RF > oscillations and fast glitches due to coupling, too much gain, > improperly compensated op-amps, in what is supposed to be a much lower > frequency circuit. This is where the "ship a scope probe with it" comes > from. The moment you probe such circuits the 10 to 15 pF in parallel > with the 10M of the probe will fix the circuit. > If you selectively touch the mechanical areas, you should be > able to do > roughly the same thing. If your finger is too "heavy" use a piece of > vinyl or rubber tubing to touch with. If its touching the anti-node, > the damping will change drastically, and it will probably be very > apparent what is vibrating or oscillating. > > Charles R. Patton > patton@......... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Karl Cunningham Subject: High background noise level Date: Mon, 04 Aug 1997 22:29:16 -0700 Hi all, Starting between 8:00 and 14:00 UTC 8/3/97, the background earth noise here has been more than double the normal, and triple to quadruple at times. It was high enough to almost completely mask the Tonga event today. Has anyone else noticed this? The only cause I can think of is the hurricane off Baja, but it's almost 2000km from here. I'm curious what the distribution of this high noise level is. I see it on Caltech's seismo-cam and Cal Berkeley's build-a-seismogram. Is it affecting Oregon? Washington? Texas? Elsewhere? I hope it goes away soon. Later, Karl Cunningham La Mesa, CA. PSN Station #40 karlc@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson Subject: interpreting seismograms Date: Tue, 05 Aug 1997 18:10:01 +1200 right you lot, in the absence of any good events lately here is some excellent reading/study material for you, to help fill in the time to the next "big one" plus it will help you to understang those wriggly lines of that next big one. Developments in Solid Earth Geophysics 18 ANATOMY OF SEISMOGRAMS by Ota Kulhanek Seismological Section, University of Uppsala, Uppsala, Sweden For the IASPEI/UNESCO Working Group on Manual of Seismogram Interpretation ELSEVIER Amsterdam - Oxford - New York - Tokyo 1990 contains heaps of diagrams and real seismograms showing phase arrivals etc check out your local university science library etc. Dave N. Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Lloyd Verhage" Subject: Your Comments Date: Tue, 5 Aug 1997 07:02:24 CST6CDT I've seen Franklin Ground Velocity Sensors for about $475. I'd be curious to hear what everyone's feelings are on these units. Are they any good? Are they worth the price? Thanks Lloyd _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: John Hernlund Subject: Re: High background noise level Date: Tue, 05 Aug 1997 09:43:16 -0700 (MST) X-Sender: hernlund@.............. To: PSN-L Mailing List Message-id: MIME-version: 1.0 Content-type: TEXT/PLAIN; charset=US-ASCII On Mon, 4 Aug 1997, Karl Cunningham wrote: > Starting between 8:00 and 14:00 UTC 8/3/97, the background earth noise here > has been more than double the normal, and triple to quadruple at times. It > was high enough to almost completely mask the Tonga event today. > Has anyone else noticed this? The only cause I can think of is the > hurricane off Baja, but it's almost 2000km from here. Yes, that would be a reasonable cause, since much of the background microseismic noise comes from atmospheric/oceanic disturbance anyways. If you would like a near real time view of AZ seismic activity go to this address at the UofA web site: http://www.geo.arizona.edu/saso/ Also, don't hesitate to e-mail people at these big stations, as they have a lot of information about the stuff going on. I get oceanic noise here in Mesa, AZ so don't be surprised if you get noise from a powerful hurricane. It is really amazing how powerful these storms can be isn't it??? The microseismic noise I have seen lately is lower frequency stuff with a period of about 2-5 seconds. It really comes out when I do an FFT and cut out all frequencies above about 0.8 Hz. > I'm curious what the distribution of this high noise level is. I see it on > Caltech's seismo-cam and Cal Berkeley's build-a-seismogram. Is it > affecting Oregon? Washington? Texas? Elsewhere? I get weird noise all the time. The wildest I have seen is when the Air force does their jet engine "turn-ups" at the AFBs around. The background noise increases across the board usually at higher frequencies though... ****************************************************************************** John Hernlund E-mail: hernlund@....... WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: ACole65464@....... Subject: Re: High background noise level Date: Tue, 5 Aug 1997 23:16:54 -0400 (EDT) Karl, I have not seen any noticeable difference with the background noise levels at my home north of Seattle over the last couple of days, but there was quite a bit here a couple of weeks ago whereby I could not see any teleseismic events. Regards, Allan Coleman _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: [Fwd: Low cost Seismographs] Date: Wed, 06 Aug 1997 13:26:33 -0600 -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". Mr. Cranswick, I am President of a small company which has designed a low cost Lehman-style inertia-weight seismograph and low noise amplifier/digitizer. We have put this package together as a product which plugs into any printer (parallel) port on a PC computer to create a complete working seismograph using software such as the EMON package to display/record the events. We are just beginning to market this package to high schools across the United States. We believe that this system will be an exciting teaching tool and hope to help a large number of schools participate in the Internet earthquake community. We are struggling a bit with setting a selling price. We have been unable to find any other companies selling low-cost seismographs (except Geophone-based systems) to aid in pricing. So, my questions are: Do you know of any companies selling similar low-cost products (less than $3000)? Do you have any suggestions on pricing? Do you have any pointers to funding available to schools to help purchase equipment such as this? Thank you for your time and I hope you can be of some assistance, Doug -- Dr. Douglas C. MacKenzie, Ph.D. Mobile Intelligence Corporation 7963 Pine Hollow, Alto, Michigan 49302-9724 mailto:doug@....................... From: "Martin Brewer" Subject: Bermuda station Date: Wed, 6 Aug 1997 21:54:51 -0300 Hello Everyone, Just to let you know that I have added a Long Period [Lehman] E-W sensor to the station. It has a period of 10 sec rather than the 19 sec of the N-S instrument. Dave Nelson suggested to have a shorter period for this second instrument as the first tends not to pick up S arrivals. Those who gave advice when I first mentioned that I was considering adding an E-W sensor will be glad to know that the new instrument is on the solid concrete floor of my cellar - as is the N-S sensor. After everyone's comments, I quickly abandoned the idea of building the second seismometer above the first on a masonry structure. Thank you all for your input on this subject. As Bermuda is closer to the Mid-Atlantic Ridge than most other stations, when the station was set up, some of you expressed the hope that Bermuda could monitor the Ridge earthquakes. I am happy to report that the N-S picked up its first Mid-Atlantic Ridge 'quake, it was virtually due East of Bermuda, 2,065km away at: USGS, NEIC: 97/08/05 02:48:43 UTC 28.38N 43.73W depth 10km Mag 5.3Mb The S arrival was not recorded - hopefully the new E-W will correct this persistent weakness in the Bermuda station. Regards, Martin _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Steve Hammond Subject: Re: Request for URL's Date: Thu, 07 Aug 1997 09:20:16 -0700 Send me a picture of you, your class, ... I have some hardware for you also. I pack it up after the UPS strick. Regards, S-- Charlie Rond wrote: > Steve, > > >Hi-- I am in the process of setting up the PSN San Jose web page. > I'll > >announce the URL in a week or two. Just to get it going, I have taken > a > >lot of stuff from the other PSN web sites. Once it is active, I'll > >start tailoring more to its own identity which I hope will be > dedicated > >to the construction of Lehman seismographs. Part of this will be a > >collection of pictures showing home built seismographs. If you have > a > >Lehman seismograph and a picture of it on the WWW I would like to add > a > >pointer to your URL. If you want to mail me a picture of your unit > so I > >can scan it drop me a note. > > That's great news. Do you want just pictures of the hardware or with > people > who built them, (school students), etc. > > Charlie Rond -\/\--Public Seismic > Network-Memphis > rond@................ (901) 360-0302 [ free BBS > ] > http://gandlf.ceri.memphis.edu/~rond > http://gandlf.ceri.memphis.edu/~rond/psn > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > > message: leave PSN-L _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: Request for URL's Date: Thu, 07 Aug 1997 14:08:08 -0600 Steve- I look forward to seeing your website; what a long, strange trip it's been. Anya, my former Russian wife, and I were recently divorced and she is already re-married, but I remember bringing her by to visit PSN San Jose at your house in Spring (May) 1991. If I have some good picture to send you, I will (although I don't have an instrument, actually I am thinking of a picture that may be partially relevant now). Regards to your family. -Edward Steve Hammond wrote: > > Hi-- I am in the process of setting up the PSN San Jose web page. I'll > announce the URL in a week or two. Just to get it going, I have taken a > lot of stuff from the other PSN web sites. Once it is active, I'll > start tailoring more to its own identity which I hope will be dedicated > to the construction of Lehman seismographs. Part of this will be a > collection of pictures showing home built seismographs. If you have a > Lehman seismograph and a picture of it on the WWW I would like to add a > pointer to your URL. If you want to mail me a picture of your unit so I > can scan it drop me a note. > > Regards, > Steve Hammond > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Charlie Rond Subject: Re: Request for URL's Date: Fri, 08 Aug 1997 04:12:11 -0500 Steve, >Send me a picture of you, your class, ... I have some hardware for you >also. I pack it up after the UPS strick. >Regards, >S-- I'll get a picture(s) for you. I'll meet with teacher Monday, but kids won't be back for a bit. Thanks in advance for hardware - no thanks to UPS :-( Take good care of yourself.. Charlie Rond -\/\--Public Seismic Network-Memphis rond@................ (901) 360-0302 [ free BBS ] http://gandlf.ceri.memphis.edu/~rond http://gandlf.ceri.memphis.edu/~rond/psn _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Walter Williams" Subject: Re: Magnetometry & other topics Date: Sat, 9 Aug 1997 16:09:20 +0000 Hello Dennis Leatart, Could you give specific magazine issue information so I may reference the article you cite. Also, do you have any pictures of the instrument you constructed which you care to share? I am studying magnetometry and ionospheric opacity as related to electric field disturbance. Thank you. Walt Williams, 97.08.09 Canoga Park, California USA dfheli@.............. ============================================================== ------- Forwarded Message Follows ------- Date: Wed, 30 Jul 1997 04:29:37 -0700 From: Dennis Leatart Reply-to: PSN-L Mailing List To: PSN-L Mailing List Subject: Re: Magnetometry HI Roger!! Found reading your post with interest. I have constructed a simple magnetometer inside a sealed jar with a mirror. It is suspended on a pendulum and a laser hits the mirror and the reflected light is projected on a scale about 12 feet away. I can observe small changes on the scale or larger ones. I have heard that small displacements of magnetic fields may actually be precursors to nearby earthquakes and that further, small changes do occur during magnetic storms on the sun. Larger storms do disrupt radio communication and can actually cause "blackouts" in certain areas-- that's why they are monitored so often--especially preWW2 and during. My magnetometer was fashioned after a type explained in an earlier issue of Sky and Telescope magazine , but would like to know how it could be more closely monitored on my computer. -- _____ __ | \.-----.-----.-----.|__|.-----. | -- | -__| | || ||__ --| |_____/|_____|__|__|__|__||__||_____| _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: microseism Date: Sat, 09 Aug 1997 17:27:45 -0700 Hi All FYI - For the last two days I have been getting a very large 0.20 hz signal (continuously- wind or not, evening or day). It has been overriding everything else. Today it has began to subside. Looks like weather related but this time of year should be fairly quite in Calif . Anyone else picking up the same? Barry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Walter Williams" Subject: Fwd[3 RB: Magnetometry - PSN-L Date: Sat, 9 Aug 1997 18:58:43 +0000 Roger, Hmm....you make it sound so easy. Thank you for the references. You probably have visited: gopher://gopher.sel.noaa.gov/ Especially: gopher://proton.sec.noaa.gov:70/11/plots Walt Williams, 97.08.09 Canoga Park, California, USA dfheli@.............. ====================================================== ------- Forwarded Message Follows ------- Date: Sat, 9 Aug 1997 18:34:54 -0500 (CDT) From: roger baker To: Walter Williams Subject: Re: Fwd[2] RB: Magnetometry - PSN-L Well Walter, the mount is nothing fancy--just a piece of thin guage aluminum from an aluminum can folded to make it more rigid as a light support for the two magnets. But I would say U-shaped so the magnets can be glued in what amount to the narrow slot. Yes I can easily see the passage of cars in the front of my house about 40 feet away, as well as magnetic noise that I am pretty sure is manmade, but I don't know where it comes from. You should try to get a copy of Chapman and Bartel's Geomagnetism, through interlibrary loan. This has the best references for this kind of magnetometer. Also check out E.A. Johnson and W. F. Steiner; Review of Scientific Instruments, Vol. 8, July 1937, p 236 for a supersensitive astatic magnetometer, built in a low tech way but sensitive enough to measure the magnetic properties of almost any common supposedly nonmagnetic material. I don't have pictures, sorry. --Yours, Roger baker _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: shammon1@............. Subject: PSN San JOSE WEB site announcement Date: Sun, 10 Aug 1997 02:00:30 -0700 This is to announce the new PSN San Jose WEB site at http://pw2.netcom.com/~shammon1/psnsj.htm It's main focus of this PSN site is on the Lehman seismograph,the history, and the people that make up the PSN. Feel free to send me an electronic photo on the PSN WALL that tells the PSN story. As there is a 1M file limit at netcom, I plan to remove and update photos in the PSN WALL page as new photos are provided. Please help support this. Take a look and let me know what you think... Regards, Steve Hammond PSN San Jose, California USA http://pw2.netcom.com/~shammon1/psnsj.htm PSN BBS San Jose 408-226-0675 _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Martin Brewer" Subject: Re: microseism Date: Sun, 10 Aug 1997 09:11:10 -0300 ---------- > From: barry lotz > Subject: microseism > Date: Saturday, August 09, 1997 9:27 PM > > Hi All > FYI - For the last two days I have been getting a very large 0.20 hz > signal (continuously- wind or not, evening or day). It has been > overriding everything else. Today it has began to subside. Looks like > weather related but this time of year should be fairly quite in Calif . > Anyone else picking up the same? > Barry Hi Barry, At Bermuda there is a constant background of about .25Hz which I have attributed to surf. All day yesterday both N-S and E-W Lehmans were picking up continuous .2Hz to .25Hz background at over twice the normal amplitude. There are no storms in the Atlantic that would have caused it. Today the background is back to normal. Regards, Martin _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Karl Cunningham Subject: Re: microseism Date: Sun, 10 Aug 1997 08:27:41 -0700 Barry -- I received the same here in So. Ca. I believe it is due to hurricane Guillermo, now weakening in the Pacific. I picked up a higher and higher microseism levels until the storm reached peak intensity. The microseism level seemed to plateau, then went to even higher levels as the large ocean swell reached the So. Ca. coast. (Over 10' waves were reported along So. Ca. beaches.) I had not realized a storm over 2000km from here could cause such a disturbance, but the signal levels really did track the progress of the storm. Fortunately, it's almost down to normal levels here too, and I am again able to record small earthquakes. Karl Cunningham La Mesa, CA. PSN Station #40 karlc@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: John Hernlund Subject: Re: PSN San JOSE WEB site announcement Date: Sun, 10 Aug 1997 13:16:03 -0700 (MST) On Sun, 10 Aug 1997 shammon1@............. wrote: > This is to announce the new PSN San Jose WEB site at > http://pw2.netcom.com/~shammon1/psnsj.htm > electronic photo on the PSN WALL that tells the PSN story. As there is a > 1M file limit at netcom, I plan to remove and update photos in the PSN > WALL page as new photos are provided. Please help support this. Steve, If you wish, I have a web site at a college here in Mesa, AZ with "almost" no limit on space. I have uploaded almost 100 MB of graphics and files to it. I could upload the pictures into a directory, to which you could link your page. The link is also stable and fast. Just let me know! ****************************************************************************** John Hernlund E-mail: hernlund@....... WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: George Bush Subject: Re: microseism Date: Sun, 10 Aug 1997 17:43:14 -0700 At 05:27 PM 8/9/97 -0700, you wrote: >Hi All > FYI - For the last two days I have been getting a very large 0.20 hz >signal (continuously- wind or not, evening or day). It has been >overriding everything else. Today it has began to subside. Looks like >weather related but this time of year should be fairly quite in Calif . >Anyone else picking up the same? > Barry Barry, I am glad you asked the list, as I was getting the same thing (I live about 100 miles north of San Francisco right on the ocean). Since I have not heard of any seismic events I was wondering if it was ocean swell from the storm off of Baja. George _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: George Bush Subject: Need a source of drum paper Date: Sun, 10 Aug 1997 18:20:18 -0700 Hello- I am getting panicky. My data-acquisition computer died about 2 months ago and I am trying to fix/replace it. Meanwhile I am relying on my drum recorder and I am about to run out of paper. Somewhere I had scrounged a large roll of 12" wide paper that has been working perfectly. It is very thin and is coated with a heat-sensitive layer on one side and was probably used in the early thermo drug store copy machines. If you know of some similar rolls of paper laying around unused, I would like to buy them from you. Or would appreciate suggestions for sources of 12" wide paper rolls or 12" X 42" sheets of paper (plain paper is what I need, the paper I am presently using just happens to have a thermal coating). George _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "James L. Skinner" Subject: Re: Need a source of drum paper Date: Sun, 10 Aug 1997 19:43:40 -0700 (MST) At 06:20 PM 8/10/97 -0700, you wrote: >Hello- > >I am getting panicky. My data-acquisition computer died about 2 months ago >and I am trying to fix/replace it. Meanwhile I am relying on my drum >recorder and I am about to run out of paper. Somewhere I had scrounged a >large roll of 12" wide paper that has been working perfectly. It is very >thin and is coated with a heat-sensitive layer on one side and was probably >used in the early thermo drug store copy machines. > >If you know of some similar rolls of paper laying around unused, I would >like to buy them from you. Or would appreciate suggestions for sources of >12" wide paper rolls or 12" X 42" sheets of paper (plain paper is what I >need, the paper I am presently using just happens to have a thermal coating). > >George > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > - George - I had the same problem a few years ago and converted my drum to ball-point pen refill (lasts approx 2 weeks); and found that fan fold computer paper (wide) with the drive tabs stripped off and properly trimmed; four sheets will make a nice full wrap. - Jim Skinner - Tucson, Ariz. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: Re: Need a source of drum paper Date: Sun, 10 Aug 1997 19:26:22 -0700 George I have used butcher paper or the back side of construction plans in the past. I'm not sure about available butcher paper widths. You can get them in rolls. Barry George Bush wrote: > > Hello- > > I am getting panicky. My data-acquisition computer died about 2 months ago > and I am trying to fix/replace it. Meanwhile I am relying on my drum > recorder and I am about to run out of paper. Somewhere I had scrounged a > large roll of 12" wide paper that has been working perfectly. It is very > thin and is coated with a heat-sensitive layer on one side and was probably > used in the early thermo drug store copy machines. > > If you know of some similar rolls of paper laying around unused, I would > like to buy them from you. Or would appreciate suggestions for sources of > 12" wide paper rolls or 12" X 42" sheets of paper (plain paper is what I > need, the paper I am presently using just happens to have a thermal coating). > > George _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert L Barns <75612.2635@..............> Subject: Unidentfied 'quakes Date: Mon, 11 Aug 1997 09:54:23 -0400 Hi gang, I have recorded 5 events on my 25 sec. Lehman (~ N-S) which have not appeared in the official reports sent to this list. This is unusual--onl= y a few in the last 18 mos. My noise level has been low during this period= =2E They are: 8/10 10:41 S/N 240/40 8/6 12:13 S/N 80/40 8/6 1:40 S/N 500/40 8/5 3:02 S/N 400/40 7/28 10:26 S/N 1000/40 No apparent P or S for any of these. The times are UTC of the surface waves and the S/N is the signal to noise ratio of the p-p counts. Even t= he 80/40 is clearly the proper shape for a quake and not some local crud. I would appreciate help in identifying these. Bob Barns (in New Jersey) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Norman_LHeureux@.......... Subject: Date: Mon, 11 Aug 1997 08:36:33 -0700 Date: Mon, 11 Aug 1997 08:36:11 -0700 Subject: Re: Need a source of drum paper Mime-Version: 1.0 Content-type: text/plain; charset=US-ASCII Norman LHeureux 08/11/97 08:36 AM There is a company by the name of Gulton or Gullton that makes thermal recorders. They used to sell thermal paper. Sorry, I don't have an address or phone number right now. ....Norm From: gbush @ mcn.org on 08/10/97 06:20 PM MST Please respond to psn-l@............. To: psn-l cc: (bcc: Norman LHeureux/ThousandOaks/Xircom) Subject: Need a source of drum paper Hello- I am getting panicky. My data-acquisition computer died about 2 months ago and I am trying to fix/replace it. Meanwhile I am relying on my drum recorder and I am about to run out of paper. Somewhere I had scrounged a large roll of 12" wide paper that has been working perfectly. It is very thin and is coated with a heat-sensitive layer on one side and was probably used in the early thermo drug store copy machines. If you know of some similar rolls of paper laying around unused, I would like to buy them from you. Or would appreciate suggestions for sources of 12" wide paper rolls or 12" X 42" sheets of paper (plain paper is what I need, the paper I am presently using just happens to have a thermal coating). George _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Karl Cunningham Subject: Mexicali Swarm Date: Mon, 11 Aug 1997 11:09:52 -0700 Hi all -- There have been *a lot* of small earthquakes (Hello- > >I am getting panicky. My data-acquisition computer died about 2 months ago >and I am trying to fix/replace it. Meanwhile I am relying on my drum >recorder and I am about to run out of paper. Somewhere I had scrounged a >large roll of 12" wide paper that has been working perfectly. It is very >thin and is coated with a heat-sensitive layer on one side and was probably >used in the early thermo drug store copy machines. > >If you know of some similar rolls of paper laying around unused, I would >like to buy them from you. Or would appreciate suggestions for sources of >12" wide paper rolls or 12" X 42" sheets of paper (plain paper is what I >need, the paper I am presently using just happens to have a thermal coating). > >George > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: microseism Date: Mon, 11 Aug 1997 17:18:28 -0600 Karl- When I was an undergraduate geology student in 1970, I saw a wonderful movie about waves and beaches that had been made at Scripps Institute of Oceanography in San Diego, California. An array of water wave sensors (water pressure, hence water depth, sensors) was installed offshore, beyond the surf zone, and monitored for more than a year. Dispersion and direction of waves indicated that the very long period waves were propagating from storms in the South Pacific near New Zealand and that shorter waves were from closer sources, local storms in the North Pacific. So I guess ocean waves can propagate a long way and are then be capable of generating microseisms when they arrive at the continental shelf. -Edward Karl Cunningham wrote: > > Barry -- > > I received the same here in So. Ca. I believe it is due to hurricane > Guillermo, now weakening in the Pacific. I picked up a higher and higher > microseism levels until the storm reached peak intensity. The microseism > level seemed to plateau, then went to even higher levels as the large ocean > swell reached the So. Ca. coast. (Over 10' waves were reported along So. > Ca. beaches.) I had not realized a storm over 2000km from here could cause > such a disturbance, but the signal levels really did track the progress of > the storm. > > Fortunately, it's almost down to normal levels here too, and I am again > able to record small earthquakes. > > Karl Cunningham > La Mesa, CA. > PSN Station #40 > karlc@....... > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David Josephson Subject: Re: Need a source of drum paper Date: Mon, 11 Aug 1997 18:25:57 -0700 (PDT) Hm; bunch of people have responded to the request for info on paper, but I guess in the froth of email no one really read what the fellow said. There's a lot of that in email discussions these days ... we get so jazzed on the speed of the medium that we don't pay much attention to the message. He needs 12 x 42 inch pieces of plain paper, not thermal, not fax, but 12 inches wide. My suggestion is to go to a big printer or printer's paper supplier and ask. There's usually a lot of trim around and if they're running big sheets some of it may already be 42 inches long. 36 x 42 is a standard size. Even if you had to buy a basis ream (36 x 42 x 500 sheets) and have it cut up you'd have 1500 sheets already the right size. -- David Josephson / Josephson Engineering / San Jose CA / david@............. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: Re: Need a source of drum paper Date: Mon, 11 Aug 1997 19:14:47 -0700 Hmm There use to be a tool called sissors which could cut paper. "Necessity is the mother of invention." Barry David Josephson wrote: > > Hm; bunch of people have responded to the request for info on paper, > but I guess in the froth of email no one really read what the fellow > said. There's a lot of that in email discussions these days ... we > get so jazzed on the speed of the medium that we don't pay much attention > to the message. He needs 12 x 42 inch pieces of plain paper, not > thermal, not fax, but 12 inches wide. > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson Subject: Re: Need a source of drum paper Date: Tue, 12 Aug 1997 14:43:50 +1200 I agree with David J., with my standard sized drum recorder, for years I have ALWAYS sourced my paper from a local printer they have a world standard sheet that when cut in half lengthways produces two separate sheets for use on the drum. I can get enough paper for $10 to last a year (thats using both sides) cant get much better than that. Dave N. At 06:25 PM 8/11/97 -0700, you wrote: >Hm; bunch of people have responded to the request for info on paper, >but I guess in the froth of email no one really read what the fellow >said. There's a lot of that in email discussions these days ... we >get so jazzed on the speed of the medium that we don't pay much attention >to the message. He needs 12 x 42 inch pieces of plain paper, not >thermal, not fax, but 12 inches wide. > >My suggestion is to go to a big printer or printer's paper supplier >and ask. There's usually a lot of trim around and if they're running >big sheets some of it may already be 42 inches long. 36 x 42 is a >standard size. Even if you had to buy a basis ream (36 x 42 x 500 sheets) >and have it cut up you'd have 1500 sheets already the right size. > >-- >David Josephson / Josephson Engineering / San Jose CA / david@............. > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson Subject: Re: Unidentfied 'quakes Date: Tue, 12 Aug 1997 18:27:16 +1200 Bob, here are some probables 97/08/10 09:20:33 16.52S 123.58E 33.0 6.0Ms WESTERN AUSTRALIA there was a New York State event (~M3.8) in here as well 97/08/05 02:48:43.3* 28.383N 43.758W 10G 5.2 5.3 1.0 60 NORTHERN MID-ATLANTIC RIDGE Dave At 09:54 AM 8/11/97 -0400, you wrote: >Hi gang, > I have recorded 5 events on my 25 sec. Lehman (~ N-S) which have not >appeared in the official reports sent to this list. This is unusual--only >a few in the last 18 mos. My noise level has been low during this period. > They are: > 8/10 10:41 S/N 240/40 > 8/6 12:13 S/N 80/40 > 8/6 1:40 S/N 500/40 > 8/5 3:02 S/N 400/40 > 7/28 10:26 S/N 1000/40 Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: Bermuda station Date: Tue, 12 Aug 1997 19:37:08 -0600 Martin- The Lehmans should have a flat response to ground velocity at frequencies higher than the natural frequency, i.e., at periods shorter than the natural period. Therefore, the 19-s Lehman should be just as sensitive as the 10-s Lehman to S-waves with periods of less than 10 s, assuming the amplification in the flat portion of the response band is equal for both instruments. Perhaps the problem is that the 19-s Lehman is more sensitive to long-period surface waves (longer than 20 s period) that, like noise, obscure the shorter period and lower amplitude S-waves. In general, it useful for all three components of a seismograph -- Z, N, E (if all exist) -- to have the same response characteristics. Looking forward to seeing your records. -Edward Martin Brewer wrote: > > Hello Everyone, > > Just to let you know that I have added a Long Period [Lehman] E-W sensor to > the station. It has a period of 10 sec rather than the 19 sec of the N-S > instrument. Dave Nelson suggested to have a shorter period for this second > instrument as the first tends not to pick up S arrivals. > > Those who gave advice when I first mentioned that I was considering adding > an E-W sensor will be glad to know that the new instrument is on the solid > concrete floor of my cellar - as is the N-S sensor. After everyone's > comments, I quickly abandoned the idea of building the second seismometer > above the first on a masonry structure. Thank you all for your input on > this subject. > > As Bermuda is closer to the Mid-Atlantic Ridge than most other stations, > when the station was set up, some of you expressed the hope that Bermuda > could monitor the Ridge earthquakes. I am happy to report that the N-S > picked up its first Mid-Atlantic Ridge 'quake, it was virtually due East of > Bermuda, 2,065km away at: > > USGS, NEIC: 97/08/05 02:48:43 UTC 28.38N 43.73W depth 10km Mag > 5.3Mb > > The S arrival was not recorded - hopefully the new E-W will correct this > persistent weakness in the Bermuda station. > > Regards, > Martin > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: Data from BM0 Date: Tue, 12 Aug 1997 20:30:01 -0600 Steve- With a little help from the Public Seismic Network (the PSN people routinely download SAC files from the DMC) and Larry Cochrane, I have extracted and spot checked some of the SAC files from Bremerton, and they look great. I will examine them more fully tomorrow. -Edward Steve Malone wrote: > > Ed and Mark > I have pulled off the 18 events for which we have triggers during > the time of the last two disks at BMO and provide the data for you in SAC > format in our FTP directory: > ftp://ftp.geophys.washington.edu/pub/out/bm0.jul12.tar > > The jul12 is the date these data were processed here, so later versions > can be kept separate. Let me know if these data look OK to you. > > Steve Malone E-mail: steve@...................... > Geophysics Program Phone: (206) 685-3811 > University of Washington FAX: (206)543-0489 > Box 351650 Office: ATG-226 > Seattle, WA 98195 -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Martin Brewer" Subject: Re: Bermuda station Date: Wed, 13 Aug 1997 19:03:30 -0300 Edward Cranswick wrote > Subject: Re: Bermuda station > Date: Tuesday, August 12, 1997 10:37 PM > > Martin- > The Lehmans should have a flat response to ground velocity at > frequencies higher than the natural frequency, i.e., at periods shorter > than the natural period. Therefore, the 19-s Lehman should be just as > sensitive as the 10-s Lehman to S-waves with periods of less than 10 s, > assuming the amplification in the flat portion of the response band is > equal for both instruments. Perhaps the problem is that the 19-s Lehman > is more sensitive to long-period surface waves (longer than 20 s period) > that, like noise, obscure the shorter period and lower amplitude > S-waves. > In general, it useful for all three components of a seismograph -- Z, > N, E (if all exist) -- to have the same response characteristics. > Looking forward to seeing your records. > -Edward Edward, Thank you for your response. I am having some technical problems with the new E-W instrument and it hasn't had a test yet. I shall keep your recommendation in mind as I get the opportunity to adjust the seismometers. Martin _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Martin Brewer" Subject: Fw: Virus Warning Date: Thu, 14 Aug 1997 18:44:46 -0300 ---------- From Martin Brewer, Bermuda -----Original Message----- From: Sean Simons Sent: Thursday, August 14, 1997 1:41 PM > >'This information was received this morning from IBM, please share it with >anyone that might access the Internet: > >If anyone receives e-mail entitled "PENPAL GREETINGS!" please delete it >WITHOUT READING IT!! This is a warning for all Internet users - there is a >dangerous virus propagating across the Internet through an e-mail message >entitled "PENPAL GREETINGS!" Do NOT download or open any message entitled >"PENPAL GREETINGS"!! > >This message appears to be a friendly letter asking you if you are interested >in a penpal, but by the time you read the letter, it is too late. The >"trojan horse" virus will have already infected the boot sector of your hard >drive, destroying all of the data present. It is a self-replicating virus, >and once the message is read, it will AUTOMATICALLY!!!!! forward itself to >anyone whose e-mail address is present in YOUR mailbox! > >This virus will DESTROY your hard drive, and holds the potential to DESTROY >the hard drive of anyone whose mail is in your IN BOX, and whose mail is in >their in box and so on. If this virus keeps getting passed, it has the >potential to do a great deal of damage to computer networks worldwide! > >Delete the message entitled "PENPAL GREETINGS!" AS SOON AS YOU SEE IT! Pass >this message along to all of your friends and other readers of the newsgroups >and mailing lists which you are on so that they are not hurt by this >dangerous virus! > >Please pass this along to everyone you know so this can be stopped.' > > > > ---------- _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson Subject: Re: Fw: Virus Warning Date: Fri, 15 Aug 1997 12:55:40 +1200 Well done for posting the warning Martin, I heard about it a couple of months ago but without a reminder one could easily forget (in absentmindedness) about not opening it Very timely.... Dave At 06:44 PM 8/14/97 -0300, you wrote: >>From Martin Brewer, Bermuda >-----Original Message----- >From: Sean Simons >Sent: Thursday, August 14, 1997 1:41 PM >>'This information was received this morning from IBM, please share it with >>anyone that might access the Internet: >>If anyone receives e-mail entitled "PENPAL GREETINGS!" please delete it >>WITHOUT READING IT!! This is a warning for all Internet users - there is a >>dangerous virus propagating across the Internet through an e-mail >message Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Roger Sorensen Subject: Re: Fw: Virus Warning Date: Thu, 14 Aug 1997 18:11:01 -0700 You may want to check out this web page about the Penpal Virus. http://www.symantec.com/avcenter/data/penpal.html _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Re: Fw: Virus Warning Date: Thu, 14 Aug 1997 17:39:16 -0700 Hi, This virus is a hoax, its the same as the GOOD TIMES virus. From the Web page below: Penpal Greetings is not a virus. It is a hoax. The “virus” does not exist. There is currently no virus that has the characteristics ascribed to Penpal Greetings. [snip] Just reading a email message or reading a text file can not spread a virus to your system. You need to execute a program for the virus to spread. A email message may have an attachment with a program that has a virus, but you would have to run the program for the virus to spread to your system. Beside executables other files can have virus in them. MS Word DOC files can also hold them. The only problem I have had with viruses had been with Word 6 doc file. -Larry The e-mail message describing the virus is similar to the original Good Times virus e-mail hoax. It could even be described as a virus hoax strain. At 06:11 PM 8/14/97 -0700, you wrote: >You may want to check out this web page about the Penpal Virus. > >http://www.symantec.com/avcenter/data/penpal.html > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson Subject: Re: Fw: Virus Warning Date: Fri, 15 Aug 1997 14:51:52 +1200 Larry your comments ARE what I have ALWAYS been lead to believe I trust that it still holds true some of these characters that write these nasties are getting pretty cunning Dave At 05:39 PM 8/14/97 -0700, you wrote: >Hi, >Just reading a email message or reading a text file can not spread a virus >to your system. You need to execute a program for the virus to spread. A >email message may have an attachment with a program that has a virus, but >you would have to run the program for the virus to spread to your system. > >-Larry Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: George Bush Subject: Thanks for all of the responses for drum paper Date: Thu, 14 Aug 1997 19:54:52 -0700 Hello- I am awed by the massive response to my plea for drum recorder paper! I want to thank the over a dozen people that responded. I have a friend in a populated area looking for some 12" roll paper for me (I live at least 3-hours away from any large city). If this falls through, I will contact other respondees that have offered to help. Thanks again- George _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: Thanks for all of the responses for drum paper Date: Thu, 14 Aug 1997 21:53:32 -0600 To all infected: Sounds like a drum recorder paper virus hoax to me! The Gov. George Bush wrote: > > Hello- > > I am awed by the massive response to my plea for drum recorder paper! I > want to thank the over a dozen people that responded. I have a friend in a > populated area looking for some 12" roll paper for me (I live at least > 3-hours away from any large city). If this falls through, I will contact > other respondees that have offered to help. > > Thanks again- George > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Charlie Rond Subject: Re: Latest Virus Warning - and other hoaxes Date: Fri, 15 Aug 1997 07:41:06 -0500 To All, The following is posted on the Department of Energy's CIAC (Computer Incident Advisory Capability) Web Page: http://ciac.llnl.gov/ciac/CIACHoaxes.html under "INTERNET HOAXES". "PENPAL GREETINGS! Warning Hoax The PENPAL GREETINGS! Hoax shown below appears to be an attempt to kill an e-mail chain letter by claiming that it is a self starting Trojan that destroys your hard drive and then sends copies of itself to everyone whose address in in your mailbox. Reading an e-mail message does not run it nor does it run any attachments, so this Trojan must be self starting. Aside from the fact that a program cannot start itself, the Trojan would also have to know about every different kind of e-mail program to be able to forward copies of itself to other people. This warning is totally a hoax." PLEASE - Everyone - Before sending a message warning about a virus, or forwarding one on, go FIRST to this Web Page and BOOKMARK it: http://ciac.llnl.gov/ciac/CIACHoaxes.html to see if it has already been identified as a hoax. I sent such "well-meant" warnings myself, before learning of the hoax web page. But the whole false warning process, besides being a terrible waste of time and bandwidth, serves only to frighten the uninitiated and dull us to a real danger when it arrives. Charlie Rond -\/\--Public Seismic Network-Memphis rond@................ (901) 360-0302 [ free BBS ] http://gandlf.ceri.memphis.edu/~rond http://gandlf.ceri.memphis.edu/~rond/psn _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Martin Brewer" Subject: Re: Latest Virus Warning - and other hoaxes Date: Fri, 15 Aug 1997 16:53:55 -0300 X-Mailer: Microsoft Internet Mail 4.70.1155 MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Message-ID: <19970815215727.AAA30197@..............> Charlie ---------- > From: Charlie Rond > To: PSN-L Mailing List > Subject: Re: Latest Virus Warning - and other hoaxes > Date: Friday, August 15, 1997 9:41 AM > PLEASE - Everyone - Before sending a message warning about a virus, or > forwarding one on, go FIRST to this Web Page and BOOKMARK it: > http://ciac.llnl.gov/ciac/CIACHoaxes.html > > to see if it has already been identified as a hoax. > > Charlie Rond Thanks for the advice, I have done as you advised. Martin Brewer _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: San Jose and the Public Seismic Network Date: Fri, 15 Aug 1997 23:49:45 -0600 15 August 1997 Dear San Jose Mercury News, Science and Technology page: In 1990, in response to a presentation at the annual meeting of the American Geophysical Union (AGU) in San Francisco, the Mercury News ran a front page story on December 7: "Scientist suggests home computers to detect quakes". Much of this suggestion has since been realized by the Public Seismic Network (PSN), an organization founded in San Jose by a group of amateur seismologists inspired by the indigenous digital talent and the seismic activity of Silicon Valley. The PSN is now an international group of amateur seismologists, concentrated in California, who record earthquakes with their own digital seismographs and exchange the waveform records via the Internet; see . I will provide some background below. In a 1978 USGS open-file report, John Lahr suggested that it would be useful to USGS goals to have the public involved in seismic recording (Lahr, 1978). However, it was not until the impetus of the 1989 Loma Prieta Earthquake that the PSN developed in the San Francisco Bay Area. In the year following the earthquake, Steve Hammond and others of San Jose, who were then employees of IBM, built their own long period seismometers and digitally recorded the signals with PC computers, using software developed by Ted Blank, also of IBM. A presentation at the 1990 San Francisco AGU, "Proposal for a high-density people's seismograph array based on home computers in the San Francisco Bay Area" (Cranswick and Banfill, 1990), excited considerable media attention largely because of the recent earthquake and because of the USGS newspaper insert (Pete Ward and others) about earthquake hazard that had been released three months previously. In January 1991, Al Lindh, who was then Branch Chief of Seismology, suggested that the PSN use electronic bulletin boards (BBSs) to communicate and to exchange digital waveform data via telephone. Steve Hammond established the first BBS at PSN San Jose soon after, and Al Lindh subsequently had a PSN PC set up in his office to function as the PSN/USGS BBS. Within two years, PSN BBSs were established in Memphis, Tennessee (Charlie Ronde) and Pasadena, California (Dorothy and Jerry Darby). The Pasadena PSN was a clearing house for public information in the first hectic days after the 1994 Northridge Earthquake, and a poster presentation (Darby et al., 1994) summarized that experience at the 1994 meeting of the Seismological Society of America in Pasadena. Following the Web explosion in 1995, the PSN was rejuvenated when Larry Cochrane established the first PSN website . Bob Hammond set up the Alaska PSN soon after. Dave Nelson established the New Zealand PSN website (mirrored at ) and created the map of the approximately 40 PSN stations that now exist worldwide. There are also currently almost 250 subscribers on the list-server maintained by the Redwood City PSN. In the Nov/Dec 1996 issue of Seismological Research Letters, Steve Malone (University of Washington, Seattle) referred to the Redwood City PSN website in his Electronic Seismologist column entitled "Near Real-time Seismology". The Redwood City PSN webserver currently serves as the repository for the PSN waveform data that is viewed by and exchanged between all -- amateur and professional seismologists, schools, and the general public. Having recently read your article, "Hang gliding leads to shuttle flight" (Posted at 5:13 p.m. PDT Monday, August 11, 1997), it occurred to me that a follow-up article to your 1990 story would be topical and appropriate for your Science and Technology page. Sincerely yours, Edward Cranswick Geophysicist, USGS -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: PSN San JOSE WEB site announcement Date: Sat, 16 Aug 1997 13:28:06 -0600 Steve- I think your idea to put all the PSN San Jose data and PSN software on a CD-ROM is excellent. One of the main problems we have at the USGS is making reliable archives of our waveform data. I have about a gigabyte of waveform timeseries from aftershock and other portable autonomous digital seismograph studies of the early 1980s sitting on 9-track tapes that are slowly developing Alzheimers. I am very glad to pay your price of $20 to have all this put together on one CD-ROM. -Edward shammon1@............. wrote: > > This is to announce the new PSN San Jose WEB site at > > http://pw2.netcom.com/~shammon1/psnsj.htm > > It's main focus of this PSN site is on the Lehman seismograph,the > history, and the people that make up the PSN. Feel free to send me an > electronic photo on the PSN WALL that tells the PSN story. As there is a > 1M file limit at netcom, I plan to remove and update photos in the PSN > WALL page as new photos are provided. Please help support this. > > Take a look and let me know what you think... > > Regards, > Steve Hammond PSN San Jose, California USA > http://pw2.netcom.com/~shammon1/psnsj.htm > PSN BBS San Jose 408-226-0675 > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: George Bush Subject: Re: Need a source of drum paper Date: Sat, 16 Aug 1997 15:22:36 -0700 David- At 06:25 PM 8/11/97 -0700, you wrote: >Hm; bunch of people have responded to the request for info on paper, >but I guess in the froth of email no one really read what the fellow >said. There's a lot of that in email discussions these days ... we >get so jazzed on the speed of the medium that we don't pay much attention >to the message. He needs 12 x 42 inch pieces of plain paper, not >thermal, not fax, but 12 inches wide. Close, but not quite. I need 42 contiguous inches of plain paper (my drum circumference plus overlap), not thermal, not fax length, and the best and simplest way would be to just find a 12" roll and I will cut it as I use it > >My suggestion is to go to a big printer or printer's paper supplier >and ask. There's usually a lot of trim around and if they're running >big sheets some of it may already be 42 inches long. I wish I could, I live over 3 hours from any city large enough to have a printer or printer paper supplier. But i will check the next time I drive in-thanks for the idea. >36 x 42 is a >standard size. Even if you had to buy a basis ream (36 x 42 x 500 sheets) >and have it cut up you'd have 1500 sheets already the right size. > Now this is a great idea, I was not aware of what the 'standard' paper sizes were. If I can't get a roll of 12" paper, I will pursue this. George _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: What is Station CMB, Columbia Univ.? Date: Sat, 16 Aug 1997 21:38:16 -0600 To Phil Giannini: I was just looking at some of the records you were uploading from Station CMB and wondering where that was in relation to your other stations and what the name Columbia Univ. signifies? -Edward -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert Avakian Subject: Re: Bob Avakian's comment Date: Sat, 16 Aug 1997 23:46:21 -0700 Oops, Dave, you're 100% correct. Had I given the kids the URL it would only have been the E-mail address. And, in retrospect, I will not give even that out so that I don't interfere with the operation of the site. After all, an 8th grader with a computer could be worse than a real computer virus :-) I agree with you, by the way, that the folks here have been very good in their communications with everyone - that's why I wanted my students to see the intechange going on here. One thing though and I'll go back to "listening", we need to police ourselves for Larry is doing more than enough already without having to deal with situations like this. Folks like Steve need "use their heads', instead. Having said that, I agree that the best thing is to let this go, and get on with the real business. Bob Avakian David A Nelson wrote: > > Bob, > this is an e-mailer list not a web site But DON'T BE SO QUICK TO > CONDEM EVERYONE ELSE who make the list so great because of a lone incident, > in the LONG time I have been assoc. with this e-mail list that is the > FIRST and hopefully the last time that I have see that sort of > behaviour..... Larry C. does have the power to stop mail from him in the > future. > > Dave > > At 06:13 PM 8/16/97 -0700, you wrote: > >Trouble with Steve's language is that we never know who is lurking. > >I'm a school teacher and was about to give the URL of the site to some > >of my Jr. High students so they could learn about quake seismology and > >see an intelligent group of serious amateurs and professionals interact. > > So much for that idea. > > > >I could easily get in real trouble with the parents down here (West > >Texas) if a parent had seen the post. > > > >Bob Avakian > > > > > > > > > > > > > > > >Steve Bechtel wrote: > >> > >> Don't be a fucking idiot. A virus can't enter your computer unless it is > >> downloaded with software. > >> > >> ---------- > >> > From: Martin Brewer > >> > To: PSN Mail List > >> > Subject: Fw: Virus Warning > >> > Date: Thursday, August 14, 1997 3:44 PM > >> > > >> > > >> > > >> > ---------- > >> > >From Martin Brewer, Bermuda > >> > > >> > > >> > -----Original Message----- > >> > From: Sean Simons > >> > Sent: Thursday, August 14, 1997 1:41 PM > >> > > > >> > >'This information was received this morning from IBM, please share it > >> > with > >> > >anyone that might access the Internet: > >> > > > >> > >If anyone receives e-mail entitled "PENPAL GREETINGS!" please delete it > >> > >WITHOUT READING IT!! This is a warning for all Internet users - there is > >> > >> > > >> > a > >> > >dangerous virus propagating across the Internet through an e-mail > >> > message > >> > >entitled "PENPAL GREETINGS!" Do NOT download or open any message > >> > entitled > >> > >"PENPAL GREETINGS"!! > >> > > > >> > >This message appears to be a friendly letter asking you if you are > >> > interested > >> > >in a penpal, but by the time you read the letter, it is too late. The > >> > >"trojan horse" virus will have already infected the boot sector of your > >> > >> > hard > >> > >drive, destroying all of the data present. It is a self-replicating > >> > virus, > >> > >and once the message is read, it will AUTOMATICALLY!!!!! forward itself > >> > >> > to > >> > >anyone whose e-mail address is present in YOUR mailbox! > >> > > > >> > >This virus will DESTROY your hard drive, and holds the potential to > >> > DESTROY > >> > >the hard drive of anyone whose mail is in your IN BOX, and whose mail is > >> > >> > > >> > in > >> > >their in box and so on. If this virus keeps getting passed, it has the > >> > >potential to do a great deal of damage to computer networks worldwide! > >> > > > >> > >Delete the message entitled "PENPAL GREETINGS!" AS SOON AS YOU SEE IT! > >> > >> > Pass > >> > >this message along to all of your friends and other readers of the > >> > newsgroups > >> > >and mailing lists which you are on so that they are not hurt by this > >> > >dangerous virus! > >> > > > >> > >Please pass this along to everyone you know so this can be stopped.' > >> > > > >> > > > >> > > > >> > > > >> > > >> > > >> > > >> > ---------- > >> > > >> > > >> > _____________________________________________________________________ > >> > > >> > Public Seismic Network Mailing List (PSN-L) > >> > > >> > To leave this list email listserver@............. with the body of the > >> > message: leave PSN-L > >> > >> _____________________________________________________________________ > >> > >> Public Seismic Network Mailing List (PSN-L) > >> > >> To leave this list email listserver@............. with the body of the > >> message: leave PSN-L > > > > > > > >_____________________________________________________________________ > > > >Public Seismic Network Mailing List (PSN-L) > > > >To leave this list email listserver@............. with the body of the > >message: leave PSN-L > > > > > Dave N. > Co-ordinator: > New Zealand PSN > Dave A. Nelson > 24 Jensen St., > Green Is., Dunedin, > South Is.. New Zealand. > > http://psn.quake.net/dave/home.htm > > IF there indeed are other parallel universes... I can now rest in the > knowledge, that in at least one of them, I am filthy rich and drive a red > Ferrari > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Re: Hints for uploads Date: Sat, 16 Aug 1997 22:34:15 -0700 At 02:07 PM 8/16/97 -0400, Bob Barns wrote: >Larry, > From time to time, you have made suggestions about how to send different >types of stuff to the psn net. How about a comprehensive set of hints >(suggestions, rules?) on this subject all in one message? > This question arose when I started to send a map of my quakes. The map >(.PCX format) is 60k or so and I don't want to load down your mail system >by sending it to all. > Sometime back, I sent a drawing in .PCX format of my fine tilt adjuster >via. FTP to psn.quake.net/incoming. This seems to have worked OK but I >don't remember where it ended up and what should have been done to notify >everyone about it. > Also, suggestions about which graphic formats are preferred would be >helpful. > Perhaps this message should be sent to all every 6 months or so. >Bob Barns I just don't have time to come up with a "comprehensive set of hints", but it is good to remind people not to send attachments to the list, now and them. A 200K attachment sent out to 250+ members produces over 50 megabytes of traffic on my system. If you have something you would like to share with the members, and you don't have access to your own ftp/web site, you can upload your file (using ftp) to my /incoming directory. This directory is open for anyone to upload files to. After uploading the file, you can then announce it to the world using this list. People can then set there ftp program or web browser to ftp://psn.quake.net/income/the_file_you uploaded and download the file. Graphic files should be in a format that a web browser can view. At this point all browser can handle GIF or JPG file types. If you have a file in another format you should be able to convert it to GIF or JPG format using any number of programs on the net. Please don't upload Window bitmap files, they are usually very large and they can be compress down to much smaller GIF/JPG files. I have found that JPG does a better job on complex color images. GIF seems to do a better job on black and white line drawings. -Larry Cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Xerox PARC Map Web Server has been discontinued. Date: Sat, 16 Aug 1997 22:58:39 -0700 Hi There, I just found out that the Xerox map server at http://pubweb.parc.xerox.com/map/ has been discontinued. Too bad... Anyone know why and if there is something similar out there. -Larry Cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Karl Cunningham Subject: Re: PSN San JOSE WEB site announcement Date: Sun, 17 Aug 1997 08:49:51 -0700 Edward, Steve, et al: I have heard that CD-ROM's have the same problem as mag tapes WRT data corruption over time. I've heard lifetime predictions on the order of 10 or 20 years for music CD's and I suspect data is no better (perhaps worse considering the greater need for accurate reproduction of the original). I don't know the relative lifetimes of home-recorded CD-ROM's vs. mass-produced ones. This might be something to investigate before committing data to CD-ROM as the only copy for long-term storage. -- Karl At 01:28 PM 8/16/97 -0600, Edward wrote: >Steve- > I think your idea to put all the PSN San Jose data and PSN software on >a CD-ROM is excellent. One of the main problems we have at the USGS is >making reliable archives of our waveform data. I have about a gigabyte >of waveform timeseries from aftershock and other portable autonomous >digital seismograph studies of the early 1980s sitting on 9-track tapes >that are slowly developing Alzheimers. I am very glad to pay your price >of $20 to have all this put together on one CD-ROM. >-Edward > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: John Hernlund Subject: Re: PSN San JOSE WEB site announcement Date: Sun, 17 Aug 1997 13:20:18 -0700 (MST) On Sun, 17 Aug 1997, Karl Cunningham wrote: > Edward, Steve, et al: > I have heard that CD-ROM's have the same problem as mag tapes WRT data > corruption over time. I've heard lifetime predictions on the order of 10 > or 20 years for music CD's and I suspect data is no better (perhaps worse > considering the greater need for accurate reproduction of the original). I > don't know the relative lifetimes of home-recorded CD-ROM's vs. > mass-produced ones. > This might be something to investigate before committing data to CD-ROM as > the only copy for long-term storage. Karl, I can check on that for you. I have recorded CD-ROMs quite a bit, and have never had a problem with them. I also remember hearing (though I never used them due to the price) that re-writable CDs have shorter lives than write once discs. Mass produced music CDs are supposed to be good for at least 80 years (thus their claim of a "life-time of musical enjoyment"), although small changes in the pits here will have little impact on music... Another thing is what resolution you are recording the data at. For instance, a randomly degraded pit will have less probability of affecting a higher order binary digit at 16 bits than a 12 or 8 bit range. Also, something like this can be compensated for by reading software that will smooth out a resultant unnatural spike... But still with all the available "affordable" recording means the CD-ROM will far surpass any other in shelf life. ****************************************************************************** John Hernlund E-mail: hernlund@....... WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David Josephson Subject: Re CD-R life Date: Sun, 17 Aug 1997 13:41:36 -0700 (PDT) John Hernlund writes > than write once discs. Mass produced music CDs are supposed to be good > for at least 80 years (thus their claim of a "life-time of musical > enjoyment"), although small changes in the pits here will have little > impact on music... Another thing is what resolution you are recording the > data at. For instance, a randomly degraded pit will have less probability > of affecting a higher order binary digit at 16 bits than a 12 or 8 bit CR-R's of all formats have interleaved data with very strong error correction so you have blocks that you can either read or not. Individual pits are several layers down in the overall scheme and you can't get to them. The strategy is to read the disks every year or so and when the error count begins to go up (that is, when the error correction has to work harder to retriece the correct data), you copy them onto new media. Write once disks are expected to last 20-30 years before there is any change in error count. Initially they have fewer errors than factory pressed disks do. > range. Also, something like this can be compensated for by reading > software that will smooth out a resultant unnatural spike... But still > with all the available "affordable" recording means the CD-ROM will far > surpass any other in shelf life. I think that's the consensus in the entertainment mastering industry as well. -- David Josephson / Josephson Engineering / San Jose CA / david@............. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jim Hannon Subject: Re: PSN San JOSE WEB site announcement Date: Sun, 17 Aug 1997 15:59:02 -0500 John Hernlund wrote: > > Karl, > I can check on that for you. I have recorded CD-ROMs quite a bit, and > have never had a problem with them. I also remember hearing (though I > never used them due to the price) that re-writable CDs have shorter lives > than write once discs. Mass produced music CDs are supposed to be good > for at least 80 years (thus their claim of a "life-time of musical > enjoyment"), although small changes in the pits here will have little > impact on music... Another thing is what resolution you are recording the > data at. For instance, a randomly degraded pit will have less probability > of affecting a higher order binary digit at 16 bits than a 12 or 8 bit > range. Also, something like this can be compensated for by reading > software that will smooth out a resultant unnatural spike... But still > with all the available "affordable" recording means the CD-ROM will far > surpass any other in shelf life. > > Both Audio and Data CD's are recorded with extensive error correction coding. This coding automatically corrects for quite a few bad bits in the data. As the number of bad bits on the disk increases it will not be seen in the reproduced data until the number of bad bits exceeds the power of the error correction algorithm. Then an entire error correction block will become unreadable. The net result of this is that you will not loose individual bits in the data you will at some point loose big sections of the data. -- Jim Hannon http://soli.inav.net/~jmhannon/ 42,11.90N 91,39.26W WB0TXL _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: shammon1@............. Subject: Re: Need a source of drum paper Date: Sun, 17 Aug 1997 22:21:56 -0700 George Bush wrote: > > David- > > At 06:25 PM 8/11/97 -0700, you wrote: > >Hm; bunch of people have responded to the request for info on paper, > >but I guess in the froth of email no one really read what the fellow > >said. There's a lot of that in email discussions these days ... we > >get so jazzed on the speed of the medium that we don't pay much attention > >to the message. He needs 12 x 42 inch pieces of plain paper, not > >thermal, not fax, but 12 inches wide. > > Close, but not quite. I need 42 contiguous inches of plain paper (my drum Your still looking for that paper? Well George, come on down! Today's your luckey day... I went digging for some truck parts for my old 52 Chevy pickup today and found a box of chart paper I bought last year and forgot about. It's 15-inches wide and rolled on a 3/4-inch tube. The roll itself has a 3 5/8 diameter. It printed in red with a grid mark pattern. If you want it you'll need to send me a mailing address. Regards, Steve Hammond Public Seismic Network, San Jose _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: shammon1@............. Subject: Re: Virus Warning Date: Sun, 17 Aug 1997 22:35:30 -0700 Robert Avakian wrote: > > Trouble with Steve's language is that we never know who is lurking. > I'm a school teacher and was about to give the URL of the site to some > of my Jr. High students so they could learn about quake seismology and > see an intelligent group of serious amateurs and professionals interact. > So much for that idea. > > I could easily get in real trouble with the parents down here (West > Texas) if a parent had seen the post. > > Bob Avakian Bob, that was a mail list not a web site. You can be assured that if you give out any of the PSN Web sites that your kids will not be subject to off colored language. We have worked with a lot of teachers over the years and expect to work with a lot more. If you think you have a problem just let the WEB site owner or the BBS sysops know and they will look into it. Remeber, most of us are also parents. Regards, Steve Hammond PSN San Jose, California _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Allan Bland" Subject: lehman seismometer Date: Mon, 18 Aug 1997 14:28:19 +0100 FROM A.Bland@............. I AM CONSTRUTING A LEMAN TYPE SESIMOMETER HERE IN THE U.K I HAVE MOST OF THE METERIAL AND PLANS BUT DO NOT NOT KNOW THE BEST LENGTH TO MAKE THE BOOM AND THE VERTICAL BRKT AND THE BEST MATERIAL AND SIZE TO MAKE THE BASE OUT OF HELP? ELECTONIC SIDE OK THANKS ALLAN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Charles R. Patton" Subject: Re: CD's & Piezo Accelerometers Date: Mon, 18 Aug 1997 09:25:14 -0700 * Re: Piezo accelerometers for seismic work. Highly unlikely. I have used extensively piezo-ceramic accelerometers of approximately the size in the web site (http://www.oceana.inter.net) illustration (cantilever beam types in SMT 1206 like packages from TDK, Murata, and others.) All of these have sensitivities of around 1 to 2 mV /g. They have typical capacities of around 200 pF. So in order to bias the front end preamp you have to parallel them with resistors of 10 M or more. This then sets the low frequency rolloff, i.e.: f = 1 / (2PiRC) = 1/(6.28*200e-12*1e7)=79.6 Hz So you have an extremely high cutoff problem first of all. Couple that with the fact you've got the 10 M resistor generating a noise voltage of approximately 300+ nV per Hz^0.5, you are left with a minimum sensitivity of only g*300nV/1mV=300 ug at 80Hz and falling from there. If you want to fight the problem of the resistor versus cutoff frequency the noise will only go up. So you're kind of in a catch 22. I don't anticipate that this is a good approach. *Re: CD lifetimes: Karl is right about the unknown lifetimes of CD's. Mass produced CD's use an evaporated aluminum film that is over coated with lacquer (the information pits are basically right under the silk screened label information -- you are looking through the bulk of the disk at the information when you look at the shiny side.) Anyway, the organic overcoat transmits moisture (water vapor) which will eventually react with the aluminum. Interestingly enough, I thought I remembered recordable CD's, to be much more moisture sensitive. But I decided to do a quick search with Altavision and found at: http://www.connact.com/~eaw/minidisc/dat_archiving.html the following quote: "Nichols, who has started a new company that specializes in audio restoration, said he's been working with Kodak's CD-R, which, through accelerated aging tests, is now said to have an archival life of 267 years......Nichols said his company is also now experimenting with using MO discs for storing 24-track recordings. "Recent info from Sony is 99 percent retention after 300 years with new forms of MO discs. They've improved a lot in the last five years," he said. " So maybe the home recordable CD's are the way to go. Charles R. Patton patton@......... Geo-Monitor newsletter info: http://www.iinet.com/users/patton/ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Charlie Rond Subject: Re: lehman seismometer Date: Mon, 18 Aug 1997 15:26:30 -0500 Allan, >I AM CONSTRUTING A LEMAN TYPE SESIMOMETER HERE IN THE U.K >I HAVE MOST OF THE METERIAL AND PLANS BUT DO NOT NOT KNOW THE >BEST LENGTH TO MAKE THE BOOM AND THE VERTICAL BRKT >AND THE BEST MATERIAL AND SIZE TO MAKE THE BASE OUT OF HELP? Do you have access to a copy of the original July, 1979 Scientific American article? Or do you have Web access? Check http://psn.quake.net/info/homefaq.txt for specific info about a seismometer. The original article specified using two pieces of half-inch (plumbing) pipe, 18-inches long joined by elbows and a 3 1/2-inch horizontal pipe for the uprights. The boom was a steel rod-5/16 inch by 75-centimeters. The base was metal about 40 x 25-centimeters. The plumbing pipe is easy to find in the USA in a hardware store. For the boom, I've used threaded steel rod as it comes in 36-inch length. The base material and size is much more variable. As an alternative to metal, I've used particle board or wood, but it needs to be 12 x 18-inch or larger and thicker than 3/4-inch to 1-inch to limit flexing. Some have reported problems with wood products absorbing moisture, warping, etc. Good luck with it. Charlie Rond -\/\--Public Seismic Network-Memphis rond@................ (901) 360-0302 [ free BBS ] http://gandlf.ceri.memphis.edu/~rond http://gandlf.ceri.memphis.edu/~rond/psn _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Ron Westfall Subject: Re: lehman seismometer Date: Mon, 18 Aug 1997 14:32:56 -0700 Hi Allan > I AM CONSTRUTING A LEMAN TYPE SESIMOMETER HERE IN THE U.K > I HAVE MOST OF THE METERIAL AND PLANS BUT DO NOT NOT KNOW THE > BEST LENGTH TO MAKE THE BOOM AND THE VERTICAL BRKT > AND THE BEST MATERIAL AND SIZE TO MAKE THE BASE OUT OF HELP? Adding to Charlie's advice ... The length of the boom is not critical, although a shorter boom will decrease the overall floor space requirements. If you use threaded rod, go for the thickest threaded rod you can. I was experiencing an unacceptable level of noise which I finally tracked down to vibrations within the threaded rod boom. I got rid of the noise by epoxying 1" angle aluminum to the boom as a stiffener. The ideal base material is stiff and does not warp, expand, or contract with humidity and temperature changes. I have heard people suggest metal and DuPont Corian countertop material. Most people have a low opinion of wood. I use a type of particle board that is made up of sawdust-sized grains. I glued three 3/4" thick sheets together to form a 2 1/4" thick base. Because the wood grains are small and randomly oriented, the base has been pretty stable. I only have to re-level it once every 2 - 4 weeks. Good luck. Ron Westfall westfall@.......... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: ralvarez@........ (Raul Alvarez) Subject: lehman seismometer Date: Mon, 18 Aug 1997 19:45:38 -0600 (MDT) Hello All, The recent postings about base material for a lehman, got me thinking about some heavy, dense material I have, and whether or not it might be suitable for a base. What I have are some school chem lab table tops, made of a hard black composition, not wood as some of the less quality ones are. Does anyone know or have any experience with this material? It requires a cement saw blade to cut and even then it takes a while. What about expansion? Raul ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~ ~ ~ "My dreams are the seeds of my reality, ~ ~ nurtured in the womb of my soul" ~ ~ RJA, 1985 ~ ~ ~ ~ ~ ~ Raul J. Alvarez ~ ~ Bellvue, Colorado ~ ~ e-mail ralvarez@........ ~ ~ homepage www.frii.com/~ralvarez ~ ~ "The Renaissance Experimenter" ~ ~ experimenter in: ~ ~ Radio and Optical Astronomy, Seismology, Weather, ~ ~ Computers, Instrumentation and Neat Stuff! ~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jim Hannon Subject: Re: lehman seismometer Date: Mon, 18 Aug 1997 21:21:15 -0500 Raul Alvarez wrote: > > Hello All, > > The recent postings about base material for a lehman, got me thinking > about some heavy, dense material I have, and whether or not it might be suitable > for a base. What I have are some school chem lab table tops, made of > a hard black composition, not wood as some of the less quality ones are. > > Does anyone know or have any experience with this material? It requires a > cement saw blade to cut and even then it takes a while. > > What about expansion? > > Raul > The chem lab tops I remember were made of slate. It would work for a base if you could figure a way to cut and drill it. I once cut a piece of slate for a pizza stone with one of those carbide hacksaws, what a chore. A diamond wet saw would have been much easier. -- Jim Hannon http://soli.inav.net/~jmhannon/ 42,11.90N 91,39.26W WB0TXL _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: ralvarez@........ (Raul Alvarez) Subject: Re: lehman seismometer Date: Mon, 18 Aug 1997 20:26:41 -0600 (MDT) >Raul Alvarez wrote: >> >> Hello All, >> >> The recent postings about base material for a lehman, got me thinking >> about some heavy, dense material I have, and whether or not it might be suitable >> for a base. What I have are some school chem lab table tops, made of >> a hard black composition, not wood as some of the less quality ones are. >> >> Does anyone know or have any experience with this material? It requires a >> cement saw blade to cut and even then it takes a while. >> >> What about expansion? >> >> Raul >> > >The chem lab tops I remember were made of slate. It would work for a >base if you could figure a way to cut and drill it. I once cut a piece >of slate for a pizza stone with one of those carbide hacksaws, what a >chore. A diamond wet saw would have been much easier. >-- >Jim Hannon >http://soli.inav.net/~jmhannon/ >42,11.90N 91,39.26W >WB0TXL > Jim, I know about the slate ones, but these are not natural, they are some manmade product. Looks a lot like slate though. Raul ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~ ~ ~ "My dreams are the seeds of my reality, ~ ~ nurtured in the womb of my soul" ~ ~ RJA, 1985 ~ ~ ~ ~ ~ ~ Raul J. Alvarez ~ ~ Bellvue, Colorado ~ ~ e-mail ralvarez@........ ~ ~ homepage www.frii.com/~ralvarez ~ ~ "The Renaissance Experimenter" ~ ~ experimenter in: ~ ~ Radio and Optical Astronomy, Seismology, Weather, ~ ~ Computers, Instrumentation and Neat Stuff! ~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: steve jones Subject: Re: lehman seismometer Date: Mon, 18 Aug 1997 21:26:32 -0700 Jim Hannon wrote: > > Raul Alvarez wrote: > > > > Hello All, > > > > The recent postings about base material for a lehman, got me thinking > > about some heavy, dense material I have, and whether or not it might be suitable > > for a base. What I have are some school chem lab table tops, made of > > a hard black composition, not wood as some of the less quality ones are. > > > > Does anyone know or have any experience with this material? It requires a > > cement saw blade to cut and even then it takes a while. > > > > What about expansion? > > > > Raul > > > > The chem lab tops I remember were made of slate. It would work for a > base if you could figure a way to cut and drill it. I once cut a piece > of slate for a pizza stone with one of those carbide hacksaws, what a > chore. A diamond wet saw would have been much easier. > -- > Jim Hannon > http://soli.inav.net/~jmhannon/ > 42,11.90N 91,39.26W > WB0TXL > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L A word of caution: before you start cutting, you might want to determine if they contain embedded asbestos - we had some of those black lab tabletops in the labs where I once worked - when we wanted to upgrade the lab furniture and reuse the tops (they were better than what we could get on the new furniture) we were told by the facilities people that the tops could not be reused/cut/drilled, but had to be disposed of because they contained asbestos! We had no recourse but to have them destroyed...what a waste! Steve Jones _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: Re: lehman seismometer Date: Mon, 18 Aug 1997 19:28:25 -0700 Hi Allan My option with the Lehman is to put the coil on the beam and the magnet on the ground. You get one wire (fine as possible going from the beam to the base but you eliminate attracting the beam with ferrous metals in the near proximity. By this fact I constructed my system of not ferrous metal. I used brass rod from a hobby shop (soldered into a truss) to form the beam & 3/4" soldered copper water pipe for the base. It is satisfactory for me. The beam length will affect the low frequency end of the sensor. The response drops off when the quake frequency goes below the natural frequency of the sensor, however when you increase the period of the sensor by making it more horizontal you increase the potential of beam drift with slight tilting of the ground. I hope this helps. Barry Ron Westfall wrote: > > Hi Allan > > > I AM CONSTRUTING A LEMAN TYPE SESIMOMETER HERE IN THE U.K > > I HAVE MOST OF THE METERIAL AND PLANS BUT DO NOT NOT KNOW THE > > BEST LENGTH TO MAKE THE BOOM AND THE VERTICAL BRKT > > AND THE BEST MATERIAL AND SIZE TO MAKE THE BASE OUT OF HELP? > > Adding to Charlie's advice ... > > The length of the boom is not critical, although a shorter boom > will decrease the overall floor space requirements. > > If you use threaded rod, go for the thickest threaded rod you can. > I was experiencing an unacceptable level of noise which I finally > tracked down to vibrations within the threaded rod boom. I got > rid of the noise by epoxying 1" angle aluminum to the boom as a > stiffener. > > The ideal base material is stiff and does not warp, expand, or > contract with humidity and temperature changes. I have heard > people suggest metal and DuPont Corian countertop material. Most > people have a low opinion of wood. > > I use a type of particle board that is made up of sawdust-sized > grains. I glued three 3/4" thick sheets together to form a 2 1/4" > thick base. Because the wood grains are small and randomly > oriented, the base has been pretty stable. I only have to re-level > it once every 2 - 4 weeks. > > Good luck. > > Ron Westfall > westfall@.......... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: JIM CRISTIANO Subject: X marks the spot Date: Mon, 18 Aug 1997 19:18:42 -0700 Hey, How does one convert deg/min/sec to decimal? I have airport sectional maps and can locate myself using the conventional method, but I can't figure out the conversion. Shielded Cable: The high-end audio cable is two conductor, twisted pair w/ shield. The twisted pair carries the signal and ground return, the shield is tied to ground at the pre-amp input only. This way the shield is at ground but carries no current. I tried this on my coil to pre-amp input ( differential also) and the results were dramatic ( sorry, no s/n ratios but I can visually verify on an O-scope). Later, Jim cristiano@........... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Richard J. Goff" Subject: Re: X marks the spot Date: Mon, 18 Aug 1997 22:36:11 -0500 JIM CRISTIANO wrote: > > Hey, > How does one convert deg/min/sec to decimal? I have airport sectional > maps and can locate myself using the conventional method, but I can't > figure out the conversion. > > Shielded Cable: The high-end audio cable is two conductor, twisted > pair w/ shield. The twisted pair carries the signal and ground return, > the shield is tied to ground at the pre-amp input only. This way the > shield is at ground but carries no current. I tried this on my coil > to pre-amp input ( differential also) and the results were dramatic > ( sorry, no s/n ratios but I can visually verify on an O-scope). > > Later, > > Jim cristiano@........... > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L Suppose you had 35deg 15 minutes 30 seconds. 30 seconds is 30/60 = .5 minutes (60 seconds = 1 minute) You angle is now 35deg 15.5 minutes 15.5 minutes is 15.5/60 degrees = .25833 deg (60 minutes = 1 deg) So your angle is 35.25833 degrees Dick G. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Re: X marks the spot Date: Mon, 18 Aug 1997 19:51:33 -0700 At 07:18 PM 8/18/97 -0700, you wrote: >Hey, > How does one convert deg/min/sec to decimal? I have airport sectional > maps and can locate myself using the conventional method, but I can't > figure out the conversion. > Jim cristiano@........... WinQuake can do the conversion for you. If you go into the Great Circle Distance calculator (under the Calculate menu) and enter the number in one of the edit boxes it will converted it. After entering the number press the enter key. WinQuake will convert the number and display it under the edit box in HH:MM:SS format. In the edit box you can place either format, DD.DDD or HH:MM:SS and WinQuake will display the number as DD.DDD in the edit box and HH:MM:SS under the edit box. -Larry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Al Allworth Subject: Re: lehman seismometer Date: Mon, 18 Aug 1997 21:06:50 -0700 At 08:26 PM 8/18/97 -0600, you wrote: >>Raul Alvarez wrote: SNIP >>> Does anyone know or have any experience with this material? It requires a >>> cement saw blade to cut and even then it takes a while. >>> A ceramic tile blade works ok. Drill with a carbide tipped bit. >>> What about expansion? Should be about as good as you can get. >>> >>> Raul >>> >> >>The chem lab tops I remember were made of slate. It would work for a >>base if you could figure a way to cut and drill it. I once cut a piece >>of slate for a pizza stone with one of those carbide hacksaws, what a >>chore. A diamond wet saw would have been much easier. >>-- >>Jim Hannon >>http://soli.inav.net/~jmhannon/ >>42,11.90N 91,39.26W >>WB0TXL >> > > >Jim, I know about the slate ones, but these are not natural, they >are some manmade product. Looks a lot like slate though. > >Raul > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > ~ ~ > ~ "My dreams are the seeds of my reality, ~ > ~ nurtured in the womb of my soul" ~ > ~ RJA, 1985 ~ > ~ ~ > ~ ~ > ~ Raul J. Alvarez ~ > ~ Bellvue, Colorado ~ > ~ e-mail ralvarez@........ ~ > ~ homepage www.frii.com/~ralvarez ~ > ~ "The Renaissance Experimenter" ~ > ~ experimenter in: ~ > ~ Radio and Optical Astronomy, Seismology, Weather, ~ > ~ Computers, Instrumentation and Neat Stuff! ~ > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > ____________________________________________________________________________ Al Allworth, Gold Beach, OR aallworth@........ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Charlie Plyler Subject: Vanuatu Date: Tue, 19 Aug 1997 00:24:58 -0400 Hello all, Just a quick explanation of the pwave2.ahn file just uploaded to the Events list. This is a recording of the electrical signals of the P wave of the 6.2 Vanuatu event as it traveled through this area. (Statesville, NC) Using Larry's Winquake program we were able to filter and detect the signal. According to seismic propagation tables the wave was on schedule. I found it interesting that the seismic wave produced such electrical activity. Later, Charlie J. Elfrad Group 35.728N 80.810W _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson Subject: Re: X marks the spot Date: Tue, 19 Aug 1997 17:05:33 +1200 many of the basic scientific calculators have that function nowdays eg Casio FX82 etc Both my casio's do Dave At 07:18 PM 8/18/97 -0700, you wrote: >Hey, > How does one convert deg/min/sec to decimal? I have airport sectional > maps and can locate myself using the conventional method, but I can't > figure out the conversion. > > Dave N. Co-ordinator: New Zealand PSN Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jean-Yves Trudel Subject: Asbestos Date: Tue, 19 Aug 1997 09:53:49 -0700 Hi! I would like to rectified about Asbestos for: Paul Alvarez Jim Hannon Steeve Jones Asbestos is dangerous only if the materiel is naturel, coming out of the mine. When the materiel is treated with some secondary chemical additive to become composite like what you have, it becomes the hardest materiel on the market. During the past 5 years, the French people try to prove with their study that Asbestos was dangerous for cancer. It's true if it comes in free particule. If you want to verify, try to cut or drill a hole, you will see how hard it is in composite format. Now if you want to work on a plate, you have to prevent yourself and put a little filter on your face to filtered the particule that become free in the air. Jean-Yves Trudel _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Steve Hammond Subject: Re: lehman seismometer Date: Tue, 19 Aug 1997 10:46:27 -0700 Allan Bland wrote: > I AM CONSTRUTING A LEMAN TYPE SESIMOMETER HERE IN THE U.K > I HAVE MOST OF THE METERIAL AND PLANS BUT DO NOT NOT KNOW THE > BEST LENGTH TO MAKE THE BOOM AND THE VERTICAL BRKT > AND THE BEST MATERIAL AND SIZE TO MAKE THE BASE OUT OF HELP? > Allan, I made mine 40-inches long. But, there is a couple of things going on here you should think about. One is the angle of the support wire. Regardless of the boom length, the support wire should have an angle between 38 to 42 degrees. Anything less than that and the centering and "boom drifting" in weather changes and soil conditions changes ( ran water) can become a problem. More than 42 degrees and the device looses sensitivity. I read a post about vibration when using thin rod. I agree, too thin of a boom can be a REAL problem. I used a 3/8-inch brass rod on my the old Falon station FS1 system and can show you many examples of vertical noise in the data when the boom was over excited and went into vertical oscillation. When I dumped that old system, I selected square aluminum 3/4 x 3/4-inch rod to construct the booms used in the current FSN and FSE systems. I make this point because the longer the boom the thicker the material required. However, this design can now support the 5-pound mass weight when using a .010-inch steel guide wire and not get vertical noise induced into the data. My final comment is about damping. You want a reasonable amount of mass however, the larger the mass the more that must be dampened. I selected a 5-pounds mass of lead because it could be formed to easily fit at the 36-inch point on the boom. Once the boom and mass are assembled, you need to check the damping before you're totally committed to your design. You want the boom to stop free swing in 2 1/2 - 3 1/2 cycles. You check this by pulling the boom to the stop and then gently releasing it. The boom should come to rest in 2 1/2 - 3 1/2 cycles. The strength and position of the damping magnets determines this adjustment and position. If you selected an oil bath damping system, the size and position of the flag in the bath becomes the critical damping adjustment. I selected magnets because oil can be messy over the long haul. The brass plate selected in my design is 3/8W x 2H x 6L - inches and suspended from the end of the boom by an L bracket and placed between two horseshoe magnets positioned with opposing faces. You can see photos that support my comments at http://pw2.netcom.com/~shammon1/equip.htm Set the contrast up on your display and the photos wont be so dark. Regards, Steve Hammond PSN San Jose, California _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Re: Vanuatu and electrical signals Date: Tue, 19 Aug 1997 16:31:41 -0700 At 12:24 AM 8/19/97 -0400, Charlie Plyler wrote: >Hello all, > >Just a quick explanation of the pwave2.ahn file just uploaded to the >Events list. > >This is a recording of the electrical signals of the P wave of the >6.2 Vanuatu event as it traveled through this area. (Statesville, NC) > >Using Larry's Winquake program we were able to filter and detect the >signal. According to seismic propagation tables the wave was on >schedule. I found it interesting that the seismic wave produced such >electrical activity. > I thought, and some please correct me if I'm wrong here, that electrical signals travel at, or near, the speed of light and not at the speed of seismic waves though rock. Sounds pretty strange to me... I looked at the "seismogram" and all I see is noise. I tried the new LOC feature and WinQuake was unable to place the P and S markers do to the distance being greater then 106 degrees (~11000 km). -Larry Cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert L Barns <75612.2635@..............> Subject: Vanuatu Date: Tue, 19 Aug 1997 20:45:02 -0400 Charlie, How were the "electrical signals of the P wave" detected and sent to SD= R? = Bob Barns _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Stephen Caruso Subject: Re: Vanuatu and electrical signals Date: Tue, 19 Aug 1997 20:56:05 -0400 (EDT) Larry, I think it was just the fact that his amp was working so well that the signal was so strong coming thru his instrument? On Tue, 19 Aug 1997, Larry Cochrane wrote: > At 12:24 AM 8/19/97 -0400, Charlie Plyler wrote: > >Hello all, > > > >Just a quick explanation of the pwave2.ahn file just uploaded to the > >Events list. > > > >This is a recording of the electrical signals of the P wave of the > >6.2 Vanuatu event as it traveled through this area. (Statesville, NC) > > > >Using Larry's Winquake program we were able to filter and detect the > >signal. According to seismic propagation tables the wave was on > >schedule. I found it interesting that the seismic wave produced such > >electrical activity. > > > > I thought, and some please correct me if I'm wrong here, that electrical > signals travel at, or near, the speed of light and not at the speed of > seismic waves though rock. Sounds pretty strange to me... > > I looked at the "seismogram" and all I see is noise. I tried the new LOC > feature and WinQuake was unable to place the P and S markers do to the > distance being greater then 106 degrees (~11000 km). > > -Larry Cochrane > Redwood City, PSN > > > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L STEPHEN CARUSO CET KB8UGH _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David Josephson Subject: Re: Vanuatu and electrical signals Date: Tue, 19 Aug 1997 18:15:32 -0700 (PDT) > I thought, and some please correct me if I'm wrong here, that electrical > signals travel at, or near, the speed of light and not at the speed of > seismic waves though rock. Sounds pretty strange to me... I don't think you're wrong, but since no one has nailed the reason for seismic electric signals, it may or may not be relevant. One idea is that SES are locally (to the receiver) produced signals correlated with local ground compression waves, so they would correspond in time to the arrival of seismic waves. There is a lot less attenuation in this path than there is for the path for electrical signals produced at the epicenter; if for no other reason than that the energy is constrained within a very narrow layer of the earth's crust rather than radiating spherically. -- David Josephson / Josephson Engineering / San Jose CA / david@............. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: Re: lehman seismometer Date: Tue, 19 Aug 1997 19:29:22 -0700 Steve I'm confused. I think I am not understanding you correctly. To me the period, and sensitivity of the sensor has to do with the relation of the beam angle to the pivot point(s)& gravity. If the concentrated mass is "below" a single pivot point system you have an oscillator. The closer to horizontal the longer the period. If there are two pivot points then the angle of a line thru both points to vertical would determine the period. The angle of the support wire will only change the force on the wire. Could you briefly explain your support system again. I had a hard time seeing the details in your photos. Thanks Barry Steve Hammond wrote: > > Allan, > I made mine 40-inches long. But, there is a couple of things going on > here you should think about. One is the angle of the support wire. > Regardless of the boom length, the support wire should have an angle > between 38 to 42 degrees. Anything less than that and the centering and > "boom drifting" in weather changes and soil conditions changes ( ran > water) can become a problem. More than 42 degrees and the device looses > sensitivity. > > Regards, > Steve Hammond PSN San Jose, California > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Charlie Plyler Subject: Re: Vanuatu and electrical signals Date: Wed, 20 Aug 1997 06:32:26 -0400 Hello Larry and all, This is true that electrical signals travel much faster than seismic waves. However, the arrival time was consistant with predicted times for the pressure wave, therefore perhaps the response received was due to electrical activity generated by the seismic wave when it passed through. This same indication has happened on other occasions when large teleseismic events have occurred. Very strange indeed! Later, Charlie J. >I thought, and some please correct me if I'm wrong here, that electrical >signals travel at, or near, the speed of light and not at the speed of >seismic waves though rock. Sounds pretty strange to me... > >I looked at the "seismogram" and all I see is noise. I tried the new LOC >feature and WinQuake was unable to place the P and S markers do to the >distance being greater then 106 degrees (~11000 km). > >-Larry Cochrane >Redwood City, PSN > > > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > Elfrad Group 35.728N 80.810W _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: JIM CRISTIANO Subject: Re: Vanuatu and electrical signals Date: Wed, 20 Aug 1997 08:26:46 -0700 Charlie Plyler wrote: > > Hello Larry and all, > > This is true that electrical signals travel much faster than seismic > waves. However, the arrival time was consistant with predicted times for > the pressure wave, therefore perhaps the response received was due to > electrical activity generated by the seismic wave when it passed through. Hi, Maybe the electrical "noise" picked up was generated by quartz crystals in the soil exhibiting the piezo effect from the strain imposed on them by the pressure wave as it reaches the recording station. Explains why the arrival times would be the same. This might also have something to do with reports of glowing lights around fault ruptures at night during activity. A good example of this is the flameless lighters. They have a crystal in them. As it gets bent it develops an elecrical charge across the crystal. With a quick release the crystal develops thousands of volts ( very little current ) and arcs across the electrodes producing the spark that lights the gas. This spark also generates broad-band RF that can be picked up on a AM radio receiver. Jim cristiano@........... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Doug Crice Subject: Re: Vanuatu and electrical signals Date: Wed, 20 Aug 1997 09:56:50 -0700 The seismo-electric effect has been reported occasionally in exploration geophysics. Unfortunately, I don't have any references at hand but it goes something like this: setting off a dynamite charge generates electrical signals (in addition to the usual acoustic ones). Once again, the Russians are the main users, possibly for gold exploration. As I recall, the effect is associated with low humidity. I have always assumed that it was piezoelectric. Doug Crice _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Psds400@....... Subject: Re: Bob Avakian's comment Date: Wed, 20 Aug 1997 14:39:36 -0400 (EDT) In a message dated 97-08-16 21:45:06 EDT, you write: << psn-l@............. (PSN-L Mailing List) >> Please remove me from this mailing list, thank you. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Charlie Plyler Subject: Re: Vanuatu Date: Wed, 20 Aug 1997 18:07:56 -0400 Hello Bob and all, The signals were detected using direct probes inserted into the earth. The "probes" are 1000 feet distant from each other and are connected to a low noise amp and two six pole low pass Butterworth filters in series, to eliminate unwanted noise. We have found that Larry's SDR card is ideal for our research of Ulf and Elf signals and noise. The discovery that we also are able to detect seismic events was a welcome sideline. Later, Charlie J. >Charlie, > How were the "electrical signals of the P wave" detected and sent to SDR? > >Bob Barns _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Martin Brewer" Subject: Re: lehman seismometer Date: Wed, 20 Aug 1997 21:58:36 -0300 ---------- > From: Allan Bland > To: psn-l@............. > Subject: lehman seismometer > Date: Monday, August 18, 1997 10:28 AM > > FROM A.Bland@............. > > I AM CONSTRUTING A LEMAN TYPE SESIMOMETER HERE IN THE U.K > I HAVE MOST OF THE METERIAL AND PLANS BUT DO NOT NOT KNOW THE > BEST LENGTH TO MAKE THE BOOM AND THE VERTICAL BRKT > AND THE BEST MATERIAL AND SIZE TO MAKE THE BASE OUT OF HELP? > > ELECTONIC SIDE OK > THANKS ALLAN > Hello Allan, For the boom I use stainless steel (non-magnetic) threaded rod 3/8 inch diameter for one instrument and 7/16 inch diameter for the other (that's all I could get) 36 inches long. The vertical bracket is 3/4 inch galvanized water pipe. For the support wire I use stainless steel fishing wire leader. For the base I use 1/2 inch thick Corian counter top material 15 inches wide by 36 inches long but it has to be reinforced. I used aluminium sliding door track down both long sides and a piece across the width immediately in front of the galvanized pipe support. Without the cross brace I found that the Corian flexed so that there were two points on either side of the centre line where the pendulum would settle. I chose a long base so that the centre of gravity of the boom assembly lies within the triangle formed by the three leveling bolts. What no one seems to tell you is that the support wire should be attached to the boom at the centre of gravity of the entire boom assembly: the point at which, when suspended vertically, the boom remains horizontal. With the boom balanced in this way there is no tendency for the knife edge to slide up or down off its pivot point on the vertical support. Regards, Martin _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Steve Hammond Subject: Re: lehman seismometer Date: Thu, 21 Aug 1997 10:07:25 -0700 Hi Allen, Barry, Martin & (Bob Lewis who dropped me a note off-line on this subject) I should have started by saying rule-of thumb... Barry. Barry lotz wrote: > > Steve > I'm confused. I think I am not understanding you correctly. To me the > period, and sensitivity of the sensor has to do with the relation of the > beam angle to the pivot point(s)& gravity. If the concentrated mass is > "below" a single pivot point system you have an oscillator. The closer > to horizontal the longer the period. If there are two pivot points then > the angle of a line thru both points to vertical would determine the > period. Right Barry-- What I was thinking about and didn't state clear enough was the same thing that Martin talks about in his note. There are two directions of alignment you have to be concerned with when setting up the pipe uprights, forward and back (period) and the other is left to right (centering) alignment. As to the 42 degrees, a professor from a US university in a white paper, which he proofs out the operation of the Lehman mathematically, calculated the figure. I have a copy of the paper in my files and will be putting it on my WEB site in a future update. You should also have a copy Barry; it was handed out in one of the PSN San Jose meetings. >The angle of the support wire will only change the force on the > wire. Yes but... It also changes the sensitivity of the left / right alignment and at some point the mass is hanging not balanced. Based on the white paper, and here is where I should have said "rule of thumb" 42 degrees is the optimum angle. 42 degrees also works out to be the correct angle for 40-inch boom and pipe uprights that are about 30-inches tall. > Could you briefly explain your support system again. I had a hard > time seeing the details in your photos. I use the pipe upright but design and created my own nozzle for the .010 upper wire by drilling a very fine hole in an small pin and then inserting it into a larger hole in the pipe. I kept breaking wires off at the sharp edge of the pipe and the insert allowed for better machine work and fewer broken wires. The lower pivot point is a sharp point in a cup, not the knife-edge used in the original design. I use high voltage test points for the point. I modified the lower knife stop block by tapping a hole in it and inserting a large allen head screw with a cup drilled in the end of it. This allows me to change the vertical alignment you described so well above Berry by turing the allen screw. I then cut slotted holes in the cross stop block were I clamp it to the pipe uprights. You change the left to right alignment of the cupped stop screw by moving the stop block left or right. I didn't mention it before but, I bolt the pipe upright unit to a 3/4 -inch by 12-inch x 12-inch aluminum base plate. I then drilled three holes in the base plate and bolt it to three machine mounting anchors cast into the 16- x 16- x 16-inch cement blocks seen in the photo. I also added three very fine thread machine screws at the edge of the aluminum plate that extend through the base plate and bottom-out on the cement. After I setup the device, I use the fine machine screws to "tweak in" the final alignments by slightly warping the base plate. > Steve Hammond wrote: > > > > > Allan, > > I made mine 40-inches long. But, there is a couple of things going on > > here you should think about. One is the angle of the support wire. > > Regardless of the boom length, the support wire should have an angle > > between 38 to 42 degrees. Anything less than that and the centering and > > "boom drifting" in weather changes and soil conditions changes ( ran > > water) can become a problem. More than 42 degrees and the device looses > > sensitivity. > > Regards, Steve Hammond PSN San Jose, California _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: roger baker Subject: Magnetometry Date: Thu, 21 Aug 1997 12:28:32 -0500 (CDT) Friends, It helps to deal with someone who knows what they're talking about. Erich Kern, who is on the PSN list, and who is the US supplier of sensitive and reasonably priced Speake magnetic fluxgate sensors made in Britain, has been quite helpful in filling in some gaps in my knowledge of magnetometry, whereas I'm a novice in this area. E-mail Erich at ekern@......... for relevant info. (He also has Humphrey accelerometers which are supposed to be quite sensitive and may be useful for PSN work. I think he's been working with Charles Patton at Geo Monitor on testing them for this purpose). At any rate, Erich has pointed out my loose informal use of the term variometer might not be accurate. What I call a variometer might be actually be termed a gradiometer. When I neutralize the earth field with external magnets and detect what is left with a suspended magnet and mirror combination, I have been calling that a magnetometer, which is quite kosher terminology, I think. When I use two equal and opposite magnets dangling from a torsion fiber but attached to the same rigid support, this is sometimes called an astatic magnetometer, but I have called it a variometer. It is mostly sensitive to local field variations rather the rather uniform earth field variations which tend to affect both magnets in equal and opposite fashion. This arrangement is useful for detecting and measuring small local weak magnetic fields such as the magnetic properties of materials placed very close to one of the two suspended magnets. Being naturally attracted to sensitive instrumentation techniques, I have been interested in pushing the limits of the magnetic fields one can measure with simple homebrew versions of classical magnetic instrumentation. My general technique, currently, is to use a fine nylon fiber attached at one or both ends for suspension. I use little iron boron neodymium magnets from Radio Shack attached to an aluminum strip along with a little chip of cheap mirror and red laser pointer for detection of movement. I use two vertical strips of window glass for support of the fiber, and these are parallel and maybe 1/2 inch apart. They are vertically mounted on a pine board supported at its perimeter with three brass leveling screws. The gaps at the edges of the glass strips are covered with black electrical tape to prevent transverse air currents. Very inexpensive, easy to build, and sensitive on the whole. I use largish ceramic magnets positioned on either side of this device to neutralize the earth field, and delicately adjusted so the magnet/mirror combination is very nearly able to rotate freely, unaffected by the earth field, which means that the torsion force from the fiber, almost as fine as spider silk, is very weak and the instrument is very sensitive when the fiber is a foot or more long. Some will object that temp or humidity variations must affect the fiber, but most of my interest has been in short range fluctuations like the micropulsations, the ultimate instrument sensitivity, how far a way I can detect small masses of iron or passing cars and the like. Erich informs me that the magnetic fluctuations of a few seconds duration are probably micropulsations of the earth field and indicate I am probably seeing magnetic variations of five gamma or less. The only new ground I have broken here, other than to remind folks of the ease of setup and sensitivity of the classical magnetic instrumentation using modern inexpensive parts, is perhaps my use of a force feedback field to lock the sensor in one position and linearize the response while retaining sensitivity. You can damp the system, but damping by it nature draws mechanical energy from the sensor and reduces the ultimate sensitivity that it is possible to retain with appropriate feedback techniques. At least that is my understanding in accord with the analogy to sensitive seismic instrumentation technique. But you can if you wish critically damp the magnet by surrounding it with a short section of copper tube, whereas a free swinging magnet undamped magnet oscillates for a long time (minutes), and is thus extremely sensitive to periodic fluctuations in the external field with the same period as the natural period of rotation as the suspended magnet. This is how I showed that my bare hand has magnetic properties --by approaching and withdrawing my hand with the same timing as the natural period of rotation as the mirror. You can also kill troublesome swings of the mirror/magnet in the same way with a small iron mass if the phase relationship is right. You approach and withdraw the mass in time with the swings and it will either increase or kill the oscillations. This technique of synchronous influencing of a high Q mechanical system allows the detection of influences that would otherwise be buried in background noise and is the mechanical analog of a lock-in amplifier, I believe. This is also the principle behind the magnet puzzle I posted to this list a few months back, and which nobody answered correctly. --Yours, Roger Baker; Science Hacker _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: roger baker Subject: Re: Magnetometry Date: Thu, 21 Aug 1997 18:49:25 -0500 (CDT) Friends, Sorry I do not have any illustrations on the net, but my magnetometer and illustrations will probably appear in the December issue of the Society for Amateur Scientists Bulletin, edited by Jack Herron, who is on PSN. This is not intended to keep anyone uninformed, but purely because my computer skills are not on the leading edge. But I'll get there. I recently managed to open David Nelson's bitmapped file on his jam jar magnetometer, which for me is doing pretty good. --Yours, Roger Baker _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz Subject: nevada events Date: Thu, 21 Aug 1997 19:18:52 -0700 Hi All 4 good ones from Nevada 3.1-4.6 Details at 11. Hopefully the Sierra Nevada fault is not on the move. Barry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: bfryer@............ (Bob Fryer) Subject: Re: Vanuatu and electrical signals Date: Fri, 22 Aug 1997 03:03:04 -0700 (PDT) David, I agree with you on the 'local effect' SESs. This seems to be a significant indicator of the phenomenon of triggering 'clusters' (both time and/or location) of large events. This is borne out by data showing that large quakes tend to occur at a higher than normal rate in the week following a nuclear test. A natural 'cluster' following a large natural event may have occurred earlier this year, in the SW Pacific region. Look at the distribution of large events for April and May, especially: 97/04/21 12:02:25 12.47S 166.21E 33.0 7.9Ms B SANTA CRUZ ISLANDS <<<<<<<<< Take care, Bob Fryer >> I thought, and some please correct me if I'm wrong here, that electrical >> signals travel at, or near, the speed of light and not at the speed of >> seismic waves though rock. Sounds pretty strange to me... > >I don't think you're wrong, but since no one has nailed the reason for >seismic electric signals, it may or may not be relevant. One idea is >that SES are locally (to the receiver) produced signals correlated >with local ground compression waves, so they would correspond in time >to the arrival of seismic waves. There is a lot less attenuation in >this path than there is for the path for electrical signals produced >at the epicenter; if for no other reason than that the energy is >constrained within a very narrow layer of the earth's crust rather than >radiating spherically. >-- >David Josephson / Josephson Engineering / San Jose CA / david@............. ----- earthquake WARNING research ----- --- animals, people, scientific evidence --- --- http://www.teleport.com/~bfryer --- _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: D06MLO12/06/M/IBM Subject: Adrian North/UK/IBM is out of the office. Date: Fri, 22 Aug 1997 13:43:57 +0000 I am out of the office from 21/08/97, returning 29/08/97. You will receive only this notification of my absence prior to my return, at which time I will respond. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Karl Cunningham Subject: Mid-Indian Ridge EQ Date: Fri, 22 Aug 1997 08:52:10 -0700 Hi, All -- I noticed that Tony Potenzo in Hawaii uploaded this event (surface waves only, or so it appears), and my seismometer's long-period output showed a similar waveform at about the same time. NEIS lists the magnitude of this event as 6.4, depth 10km. But it was over 18000km from my station (163 deg) -- which seems too far away to record an event of this magnitude, although I think a fairly shallow event such as this ought to produce strong surface waves. Is it likely I (& Tony) really recorded this event? Being relatively new to this, I don't have the experience to say how likely this might be. Thanks in advance for any comments. Karl Cunningham La Mesa, CA. PSN station #40 karlc@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jean-Yves Trudel Subject: Streckeisen Date: Fri, 22 Aug 1997 12:40:08 -0700 Hi list! I try to find tech info on the STS-2 and STS-1 Streckeisen seismometer. On the net, we can only see seisimic stations that use STS-1 seismometer. What I would like to see is the tech sheet, and why it's a broadband seismometer, wich kind of feedback signal they used, what kind of sensors they used, the dynamique range, sensitivity, and what is the difference between STS-2 and STS-1,are they design for long periode, and the price. Is somebody on the list can tell me more or where to look ? Tks! Jean-Yves _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: D06MLO12/06/M/IBM Subject: Adrian North/UK/IBM is out of the office. Date: Fri, 22 Aug 1997 18:10:54 +0000 I am out of the office from 21/08/97, returning 29/08/97. You will receive only this notification of my absence prior to my return, at which time I will respond. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Steve Hammond Subject: Re: Adrian North/UK/IBM is out of the office. Date: Fri, 22 Aug 1997 12:30:06 -0700 HEY LARRY---- The is an echo comming out of an IBM VM exec called GONE. It is going to echo this response to every post made to this mail list until Adrian returns and reads his mail. Your going to need to remove him from the mail list to stop it. Regards, Steve Hammond D06MLO12/06/M/IBM wrote: > I am out of the office from 21/08/97, returning 29/08/97. You will receive > only this notification of my absence prior to my return, at which time I will > respond. > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: [Fwd: Re: TREMOR prototype update] Date: Fri, 22 Aug 1997 15:05:03 -0600 -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". From: Edward Cranswick Subject: [Fwd: TREMOR prototype update] Date: Fri, 22 Aug 1997 15:04:43 -0600 -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". From: Edward Cranswick Subject: [Fwd: Sites for TREMOR prototypes] Date: Fri, 22 Aug 1997 15:05:26 -0600 -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". From: "Jacquie C. Cowe" Subject: testing Date: Fri, 22 Aug 1997 14:10:51 -0700 (PDT) test 1 _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert L Barns <75612.2635@..............> Subject: WWVB clock Date: Fri, 22 Aug 1997 20:07:25 -0400 Hi gang, On 7/17, I posted a note about the ARCRON clock--here is a cheaper alternative. A friend brought this to my attention:A clock which is alwa= ys correct to better than 1 sec. It is a black box 3 5/8 X 2 1/4 X 11/16" with shafts sticking out one side. It uses 1 AA battery. It corrects it= s quartz oscillator from time signals from WWVB on 60 kHz from Ft. Collins NIST. The antenna is in the box. You supply the dial (non-metallic) and= there is a choice of shaft lengths. With your choice of hands, $28.95! = =46rom Klockit, 1-800-KLOCKIT. We can probably figure out how to bring out a 1 pulse/sec signal. Bob Barns _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert L Barns <75612.2635@..............> Subject: Mid-Indian Ridge EQ Date: Fri, 22 Aug 1997 20:42:29 -0400 Karl Cunningham, No surprise at being able to see a 6.4 at 160 deg. I got it with a signal to noise ratio of 10--that much signal is very obvious even in SDR= (without filtering in WINQUAKE). I have a 0.08Hz cut-off low pass filter= before the A/D and this improves the S/N. Here, it had a rather strange shape--there was rather constant amplitud= e stuff with S/N ~ 3 for about 45 mins. followed by stuff with S/N of 10 at= rather constant amplitude for about 50 mins. The coda after that fell of= f rapidly to back-ground over the next 20 mins. Bob Barns _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: [Fwd: Re: New seismometers] Date: Fri, 22 Aug 1997 21:00:45 -0600 -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". From: Edward Cranswick Subject: Re: TREMOR site Date: Fri, 22 Aug 1997 21:48:37 -0600 Dick- Please send your questions/response to John Evans and/or the PSN-L Mailing List. I am just passing along messages and live and work in Colorado. -Edward Dick Morgret wrote: > > Would the Hayward hills be suitable for a TREMOR site? > I sit just off the Hayward Fault and between the East and Wesr Chabot > faults. > Dick Morgret -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Karl Cunningham Subject: Re: Mid-Indian Ridge EQ Date: Sat, 23 Aug 1997 07:31:52 -0700 Bob -- Thanks for the reply. My SNR wasn't nearly as high as yours -- about 2:1 at best even with filtering. In this frequency band (.01Hz to .5Hz), I have quite a bit of noise and need to filter unless the signal is really strong. The signal here was only above noise level for about 45 minutes -- that might correspond to your SNR of 10 for 50 minutes. Thanks again, Karl Cunningham La Mesa, CA. PSN Station #40 karlc@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson Subject: new PSN maps Date: Sun, 24 Aug 1997 03:33:58 +1200 Hi Ya All, in yet another effort to alleviate the station congestion on the single PSN map I have now started on my Promise/threat to do a major upgrade.! There will be 4 clickable regions on the main world map that will bring up zoomed in regional maps for:... North America (USA, Sthrn Canada, Bermuda) ; California; New Zealand and the British Isles/Wstrn Europe. At present the Nth American and the Californian maps are active and the the dots within those regions are inactive ie. they are a rough indication on station location. Please have a look, see what you think, give me any CONSTRUCTIVE critism or let me know of any spelling boo boos etc Don't FORGET to click on reload to load in the latest page updates Notes: on the Nth Am. map the only station's home town I could not find on any map was that of Lucas Haag...... I positioned it according to the supplied Lat. and Long. data. On the Calif. map I could not find Roger's hometown of Chatsworth.... L.A. area or Gregory's town of Altadena, also L.A. area ..... once again used supplied Lat. and Long. If I am too far out please give me a better loc. TNX Finally Karl asked about the permanence of the station number's in the database..... there should be NO reason for it to change Dave Co-ordinator: New Zealand PSN Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert L Barns <75612.2635@..............> Subject: Map of my 'quakes & FTP'ing Date: Sat, 23 Aug 1997 13:16:03 -0400 Hi gang, This is to pass along some hard-won info. Maybe everyone else knows al= l this stuff but here it is anyway. Larry said to get my map of my 'quakes on his system (see below), just FTP it to psn.quake.net/incoming. Well, I found out that receiving FTP i= s easy but sending is a special problem. = A friend told me that a special program is needed. He suggested a pkg.= called ws_ftp32.zip. This I downloaded thru Compuserve but should be avail. at www.ipswitch.com and many other places. This contains WS_FTP Professional which I installed it under Windows 3.1 (the 16 bit vers.) It= is a snap to use. Price is $37.50. There is also said to be a free but limited version. I used this to do the FTP file transfer of the map. I nearly fell out = of my chair when the prog. reported that the 16.6k .GIF file was sent in 0.3= secs!! (with a 14.4 modem!!) However, I looked on Larry's system and it = is there! About the map:Another friend had several old 360k floppies containing l= at and lon coordinates. These were placed in the public domain by Fred Pospeschil and Antonio Riveria from original data from the CIA. I wrote = a BASIC-like program in DesignCAD to read a file of lat and lon and draw it= in the CAD program. I can send these data to anyone who can use them. = DesignCAD basic has some "features" like no other dialect of BASIC--these= slowed me down a lot. Another DesignCAD-basic program then read a file of the lat and lons o= f my quakes and put those on the map. This prog. also drew in the meridian= s. A second version of this whole kludge drew the map which is centered on the Pacific. DesignCAD can output a .GIF file of a drawing. This is the= one avail. on Larry's board. I find it interesting that the 'ring of fire' and the mid-atlantic ridg= e are fairly obvious with only 111 'quakes. = You can see this masterpiece by doing ftp://psn.quake.net/incoming an= d then downloading worlmapr.gif. (The r version is the one rotated to center on the= Pacific.) Bob Barns _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Erich F. Kern" Subject: I searched out Klockit's information and ordered one. I let you know Date: Sat, 23 Aug 1997 18:40:44 -0700 forwarding this for Charles Patton *************************************************************** Please visit our web site at: http://www.dconn.com/FatQuartersSoftware Thank you *************************************************************** ---------- > From: Karl Cunningham > To: psn-l@............. > Subject: Re: Mid-Indian Ridge EQ > Date: Saturday, August 23, 1997 07:31 > > Bob -- > > Thanks for the reply. My SNR wasn't nearly as high as yours -- about 2:1 > at best even with filtering. In this frequency band (.01Hz to .5Hz), I > have quite a bit of noise and need to filter unless the signal is really > strong. The signal here was only above noise level for about 45 minutes -- > that might correspond to your SNR of 10 for 50 minutes. > > Thanks again, > > > Karl Cunningham > La Mesa, CA. > PSN Station #40 > karlc@....... > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Erich F. Kern" Subject: Fw: Re:WWVB clock Date: Sat, 23 Aug 1997 18:49:25 -0700 Forwarding for Charles Patton *************************************************************** Please visit our web site at: http://www.dconn.com/FatQuartersSoftware Thank you *************************************************************** ---------- > From: Charles R. Patton > To: jccowe@......... > Subject: Re:WWVB clockI searched out Klockit's information and ordered one. I let you know how it works out when I get it. Below is the URL, but it doesn't show the kit referred to, so I just left a long message on their answering machine: Klockit http://www.klockit.com/ (800) KLOCKIT (i.e. (800) 556-2548) M-F 8-8 Sat 8-4 POB 629 Lake Geneva, WI 53147 Just for fun, did a quick Altavision search on ARCON and among the hits found the following ARCON relevant URL's: http://www.arctime.com/ ========================== http://www2.exnet.com/NTP/ARC/ARC.html This one has an article on using the clock as a time standard in computer networks. It has C code drivers for the purpose. It would be a very short hop, skip and jump to put this into a PC. It further more has two RS232 output clocks from different manufacturers. The Galleon site is selling two units designed in Germany -- however my take on it is that they are designed for the radio transmissions from MSF out of Rugby, England. Those transmissions although on 60 KHz also, the time code timing and modulation are not the same thus MST time code receivers would NOT be compatible with WWVB from Colorado in the USA unless the the software were written to be dual mode. (see time code references to MST, and WWVB references below.) URL's are: http://www.solnet.co.uk/galleon/ http://www2.exnet.com/NTP/ARC/driver27.htm http://www.orionsys.co.uk/galleon/galleon.htm ====================== Of particular interest is the last entry which is actually Galleon's home page. They have OEM components, and among them appears to be some suitable for USA use. I have requested information from them and if it pans out I'll do a Geo-Monitor article on it. I pursued trying to get information and parts on the Oregon Scientific "Time Machine". Unfortunately the US outfit is a marketing arm. The main company is Integrated Display of Hong Kong and their aim is high volume, consumer goods and so basically the gentleman I talked to was nice enough, but the final message was, "Go away, boy, you bother me!" We just don't have the volume clout necessary. One interesting thought though is that maybe the design really came from Galleon. Now wouldn't that be a twist? A very interesting page with a bibliography of VLF receivers for MST is: http://www.npl.co.uk/npl/cetm/taf/msf60.html -npl- is the National Physical Laboratory, England's equivalent of the USA's NIST. Time code descriptions: http://www.npl.co.uk/npl/cetm/taf/timecode.html is a description of the time code for MST from NPL in England. This is considerably different that the NIST format available at: http://www.boulder.nist.gov/timefreq/pubs/sp432/s_appc.htm So if your VLF clock has a embedded microprocessor to decode the signals, it would definitely need different algorithms to handle both services. Charles R. Patton editor, Geo-Monitor Geo-Monitor home page: http://www.iinet.com/users/patton/ email: patton@......... > Date: Saturday, August 23, 1997 17:50 > > I searched out Klockit's information and ordered one. I let you know > how it works out when I get it. Below is the URL, but it doesn't show > the kit referred to, so I just left a long message on their answering > machine: > Klockit > http://www.klockit.com/ > (800) KLOCKIT (i.e. (800) 556-2548) > M-F 8-8 Sat 8-4 > POB 629 > Lake Geneva, WI 53147 > > > Just for fun, did a quick Altavision search on ARCON and among the hits > found the following ARCON relevant URL's: > http://www.arctime.com/ > ========================== > http://www2.exnet.com/NTP/ARC/ARC.html > This one has an article on using the clock as a time standard in > computer networks. It has C code drivers for the purpose. It would be > a very short hop, skip and jump to put this into a PC. It further more > has two RS232 output clocks from different manufacturers. The Galleon > site is selling two units designed in Germany -- however my take on it > is that they are designed for the radio transmissions from MSF out of > Rugby, England. Those transmissions although on 60 KHz also, the time > code timing and modulation are not the same thus MST time code > receivers would NOT be compatible with WWVB from Colorado in the USA > unless the the software were written to be dual mode. (see time code > references to MST, and WWVB references below.) > URL's are: > http://www.solnet.co.uk/galleon/ > http://www2.exnet.com/NTP/ARC/driver27.htm > http://www.orionsys.co.uk/galleon/galleon.htm > ====================== > Of particular interest is the last entry which is actually Galleon's > home page. They have OEM components, and among them appears to be some > suitable for USA use. I have requested information from them and if it > pans out I'll do a Geo-Monitor article on it. I pursued trying to get > information and parts on the Oregon Scientific "Time Machine". > Unfortunately the US outfit is a marketing arm. The main company is > Integrated Display of Hong Kong and their aim is high volume, consumer > goods and so basically the gentleman I talked to was nice enough, but > the final message was, "Go away, boy, you bother me!" We just don't > have the volume clout necessary. One interesting thought though is > that maybe the design really came from Galleon. Now wouldn't that be a > twist? > > A very interesting page with a bibliography of VLF receivers for MST > is: > http://www.npl.co.uk/npl/cetm/taf/msf60.html > -npl- is the National Physical Laboratory, England's equivalent of the > USA's NIST. > > Time code descriptions: > http://www.npl.co.uk/npl/cetm/taf/timecode.html > is a description of the time code for MST from NPL in England. This is > considerably different that the NIST format available at: > http://www.boulder.nist.gov/timefreq/pubs/sp432/s_appc.htm > So if your VLF clock has a embedded microprocessor to decode the > signals, it would definitely need different algorithms to handle both > services. > > Charles R. Patton > editor, Geo-Monitor > Geo-Monitor home page: http://www.iinet.com/users/patton/ > email: patton@......... > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: PSN abstract for AGU: solicitation of comments Date: Sat, 23 Aug 1997 23:36:25 -0600 PSN members- Below (also attached as a MS Word 6.0/95 document) is the rough draft of an abstract entitled "Public Seismic Network (PSN): a Model for Preparing People to use Real-time Information About Natural Hazards" that we are preparing to submit to the 1997 Fall Meeting of the American Geophysical Union (AGU) to be held in San Francisco, California, USA, on 8-12 December 1997 . The abstract will be submitted to Special Session U12: "Hazard Mitigation: Use of Real-Time Information" (see below following abstract) . The authors are myself, Ben Gardner (a USGS volunteer who was editor of the 1991 PSN Newsletter and editor and co-author of various other PSN/USGS publications), and you, the Public Seismic Network. Before submitting the abstract to AGU, I am soliciting your (PSN's) comments and criticism of the abstract at the same time I am submitting it to my office of the U.S. Geological Survey (USGS) for internal review. Though Ben and I and others, and Steve Hammond and Dorothy & Jerry Darby and other PSN members have published several PSN abstracts/articles before, this is the first time that a rough draft will be reviewed by all PSN members (courtesy of Larry Cochrane) prior to publication. Please send me your responses ASAP and before Tuesday, 26 Aug 1997, at which time I will electronically submit the revised version to AGU. Looking forward to your remarks. -Edward ************************************************************************ Public Seismic Network (PSN): a Model for Preparing People to use Real-time Information About Natural Hazards E. Cranswick and B. Gardner (U.S. Geological Survey, MS 966, Box 25046, Federal Center, Denver, CO 80225; 303-273-8609; cranswick@......... Public Seismic Network (http://psn.quake.net/, psn-l@.............. When an earthquake occurs, unlike any other natural hazard, every individual in the population at risk is aware within seconds that a dangerous event has happened. Without the aid of any technology, the consciousness of everyone affected is almost instantaneously focused on the same subject. Typically, the spatial density of this information and its distribution among those at risk is not exploited. Instead, authorities broadcast the absurdly redundant message to the populace that an earthquake has occurred. A program for monitoring natural hazards for the public good requires public participation if its observations are to be used effectively to mitigate those hazards. The Public Seismic Network (PSN), rather than relegating them to the role of sitting ducks waiting to be devastated by the unexpected, enables people to become aware that earthquakes are an expression of the normal, on-going behavior of Earth processes, i.e., just as natural as the weather. The PSN is an international group of amateur seismologists, concentrated in California, who record earthquakes with their own digital seismographs and exchange the waveform records and communicate with each other via the Internet. At present, the PSN consists of about 50 seismograph stations, about 250 subscribers to its email list server, and about 10 websites. In urban areas of high seismic risk, a grassroots organization like the PSN could form a constituency of well-informed residents who not only know how to respond to catastrophic earthquakes but also support hazard mitigation programs in the community. Rather than just building faster ambulances to mitigate the impact of heart attacks, it is more effective to modify the public habits of exercise and diet. The PSN is a model for using technology to connect human awareness to, rather than shield it from, the environment. ************************************************************************ U12 Hazard Mitigation: Use of Real-Time Information Accurate information available just before, during, or immediately after hazardous events can be used to reduce life loss and property damage and to speed response and recovery. This session will look at examples of real-time data collection and analysis, how critical information can be communicated rapidly, and how agencies, businesses, and individuals put such information to use. The emphasis will be on natural hazards such as storms, floods, earthquakes, tsunamis, volcanic eruptions, landslides, wildfires, and space weather. Conveners: Peter Ward, U.S. Geological Survey, 345 Middlefield Road, MS 977, Menlo Park, CA 94025, Phone: 415-329-4736, E-mail: ward@.................... and Lloyd Cluff, Chairman, California Seismic Safety Commission, Pacific Gas and Electric Company, P.O. Box 770000, Mail Code N4C, San Francisco, CA 94177, Phone: 415-973-2791, E-mail: lsc2@....... ************************************************************************ -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". From: Edward Cranswick Subject: Re: TREMOR site Date: Sat, 23 Aug 1997 23:55:17 -0600 Dick- I want to apologise for being a little short with you yesterday about your very prompt response to the request for TREMOR sites from John Evans, USGS Menlo Park, California, that I forwarded to PSN-L. Despite my previous protestations of ignorance, of being just a good ole Colorado country boy, I did live and work at USGS Menlo Park from 1980-1985, and I think your location is excellent and that you would be a perfect candidate for a TREMOR site. However, now I am in Colorado, and the TREMOR Project is a product of USGS Menlo Park, and they are going to make all the decisions. But nonetheless, I think your place is a natural! Thank you. -Edward Dick Morgret wrote: > > Would the Hayward hills be suitable for a TREMOR site? > I sit just off the Hayward Fault and between the East and Wesr Chabot > faults. > Dick Morgret -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: [Fwd: Sites for TREMOR prototypes] Date: Sun, 24 Aug 1997 00:48:03 -0600 Mark- Like the message from Dick Morgret to me on the same subject (see my second recent reply to him on the PSN-L), I have forwarded your message to me about the suitability of your residence as a TREMOR site to the TREMOR chief honcho, John Evans (Dick, I forgot to mention to you that I had forwarded your message to John). I think that your place in the Santa Cruz Mountains, California, would also be a perfect TREMOR site. The night of the 1989 Loma Prieta (California) Earthquake, Robert Banfill and I were in Golden, Colorado, writing PC software in preparation for our return to the Soviet Union to continue studies of the 1988 Spitak Earthquake in Armenia, but we spent the next 24 hours driving to the house of my ex-wife in East Palo Alto in the San Francisco Bay Area. We spent the subsequent fortnight in a motel in Santa Cruz, drinking too much espresso, ostensibly trying to analyze data from portable autonomous digital seismographs we had deployed across downtown Santa Cruz (what had been the Mall), and sleeping with too many PCs. I did spend one afternoon "out in the field" up in the hills, but it is all a little vague now (as it was then: the Santa Cruz effect). I didn't drive over the hill on Highway 17 until about two weeks after the mainshock; we originally drove to Santa Cruz down US 1 from Half Moon Bay and later through Watsonville where we rented our PCs. Within a couple of months, we should have some of the results of our Loma Prieta investigations out on the Web (they were published on hardcopy several years ago). I am interested in seeing what you record with your sensors; let me know. Good luck with TREMOR! -Edward Mark Halliday wrote: > > At 03:05 PM 8/22/97 -0600, you forwarded to psn mailing list: > >I NEED YOUR HELP to decide during the next three weeks where to site > >these prototypes. > >The upcoming Open House is an IDEAL place to advertise for volunteers > >to site these instruments (mostly in the garages of wood-frame homes), > >hence the urgency. > > Are you looking for volunteers? What are the site requirements? > UPS Power? > > I live in Ben Lomond which is near Scotts Valley and Loma Prieta. > My house is half was up the mountain west of Ben Lomond. Soil is > shallow ancient crumbling granite, typical of the Santa Cruz > mountains. Parts of the house perimiter wall foundation are in > contact with harder granite. (Sorry I don't know more technical terms.) > There is a built-in garage with concrete slab. I don't know > about PBMS coverage. I have been testing an SG sensor and vertical > sensor and use SDR / WinQuake. > > I was not home during the '89 quake. I was commuting on hwy 280 > near Menlo Park. The hwy had some good rolling action, difficult > to keep the car in my lane. Had to drive over a 4" dropoff crack > that went across the hwy (about 6-8 lanes at that point). > I got home the next day due to gridlock in San Jose (no power) and > mountain road closures. The house was fine except for some broken > dishes and a two week power outage. A heavy wood burning stove > had moved about a foot. > > Thank you for keeping the psn mailing list informed of usgs > activities and let me know if I can be of help. > > - Mark -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: new PSN maps Date: Sun, 24 Aug 1997 01:25:20 -0600 Dave- Your map is PBR! (pretty bloody remarkable: I figured that would get by the Yank censors). On one hand, I would like to show the revised map to my supervisor, but I know he'd say something like: "I don't want you wasting your time on PSN, when you could instead be making a map like that for my project" And I know he wouldn't like my reply: "I don't do JAVA, sir; I can only do FORTRAN". Anyway, Dave, you keep up the good work, and I'll try and focus on getting all the credit. -Edward PS. It nice to know where Montana is after all these years ... I've been wondering ... and otherwise, seeing the relationship of everyone to everyone else makes everthing alot clearer, don't you think? PPS. In terms of substantive remarks, it should be "courtesy of NEIC" not "courtsey of NEIC". David A Nelson wrote: > > Hi Ya All, > in yet another effort to alleviate the station congestion on > the single PSN map I have now started on my Promise/threat to do a major > upgrade.! > > There will be 4 clickable regions on the main world map that will bring up > zoomed in regional maps for:... North America (USA, Sthrn Canada, Bermuda) ; > California; New Zealand and the British Isles/Wstrn Europe. > > At present the Nth American and the Californian maps are active and the the > dots within those regions are inactive ie. they are a rough indication on > station location. > > Please have a look, see what you think, give me any CONSTRUCTIVE critism > or let me know of any spelling boo boos etc Don't FORGET to click on > reload to load in the latest page updates > > Notes: on the Nth Am. map the only station's home town I could not find > on any map was that of Lucas Haag...... I positioned it according to the > supplied Lat. and Long. data. > > On the Calif. map I could not find Roger's hometown of Chatsworth.... > L.A. area or Gregory's town of Altadena, also L.A. area ..... once again > used supplied Lat. and Long. > > If I am too far out please give me a better loc. TNX > > Finally Karl asked about the permanence of the station number's in the > database..... there should be NO reason for it to change > > Dave > > Co-ordinator: > New Zealand PSN > Dave A. Nelson > 24 Jensen St., > Green Is., Dunedin, > South Is.. New Zealand. > > http://psn.quake.net/dave/home.htm > > IF there indeed are other parallel universes... I can now rest in the > knowledge, that in at least one of them, I am filthy rich and drive a red > Ferrari > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: Map of my 'quakes & FTP'ing Date: Sun, 24 Aug 1997 01:42:18 -0600 Bob- Very excellent map! and very excellent effort to record and associate all those events and to work your way through the labyrinth of cobwebbed code to produce such a succinct representation of seismo-plate-tectonic truth. If I had done something like that for my thesis advisor, Dr. Lynn Sykes, when I was in graduate school, I'd be Dr. Cranswick today (instead of the "Renegade Seismologist"; the title bestowed by the former Office Chief of the former USGS OEVE) Truly a masterpiece! -Edward Robert L Barns wrote: > > Hi gang, > This is to pass along some hard-won info. Maybe everyone else knows all > this stuff but here it is anyway. > Larry said to get my map of my 'quakes on his system (see below), just > FTP it to psn.quake.net/incoming. Well, I found out that receiving FTP is > easy but sending is a special problem. > A friend told me that a special program is needed. He suggested a pkg. > called ws_ftp32.zip. This I downloaded thru Compuserve but should be > avail. at www.ipswitch.com and many other places. This contains WS_FTP > Professional which I installed it under Windows 3.1 (the 16 bit vers.) It > is a snap to use. Price is $37.50. There is also said to be a free but > limited version. > I used this to do the FTP file transfer of the map. I nearly fell out of > my chair when the prog. reported that the 16.6k .GIF file was sent in 0.3 > secs!! (with a 14.4 modem!!) However, I looked on Larry's system and it is > there! > About the map:Another friend had several old 360k floppies containing lat > and lon coordinates. These were placed in the public domain by Fred > Pospeschil and Antonio Riveria from original data from the CIA. I wrote a > BASIC-like program in DesignCAD to read a file of lat and lon and draw it > in the CAD program. I can send these data to anyone who can use them. > DesignCAD basic has some "features" like no other dialect of BASIC--these > slowed me down a lot. > Another DesignCAD-basic program then read a file of the lat and lons of > my quakes and put those on the map. This prog. also drew in the meridians. > A second version of this whole kludge drew the map which is centered on > the Pacific. DesignCAD can output a .GIF file of a drawing. This is the > one avail. on Larry's board. > I find it interesting that the 'ring of fire' and the mid-atlantic ridge > are fairly obvious with only 111 'quakes. > You can see this masterpiece by doing ftp://psn.quake.net/incoming and > then downloading > worlmapr.gif. (The r version is the one rotated to center on the > Pacific.) > Bob Barns > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Allan Bland" Subject: thanks Date: Sun, 24 Aug 1997 11:35:44 +0100 from allan bland THANKS TO ALL FOR INFO ON LEHMAN SEISMOGRAPH IAM STARTING TO BUILD NOW WILL LET YOU KNOW IF IT WORKS????. THANKS AGAIN ALLAN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson Subject: Re: new PSN maps Date: Mon, 25 Aug 1997 01:00:46 +1200 TNX Ed., I enjoy doing the mapmaking as much as I want the PSN's presence out on the web in the best way possible..... that is my burden Your's is to continue with the PSN publicity in the other ways ..... well you should know by now that supervisors have no sense of fair play..... if it doesn't make money and pay its way then don't get involved. Yes I really like the USA map ... at a glance it is far easier to pin down the stations. I dug out many large National Geographic maps, of the different states, that I have collected over the years to search for the various towns. courtesy !! yeah thanks didn't pick that one over all I'm a good speller Can't remember if that was a genuine mis-spell or a slip on the k.brd. toodles Dave At 01:25 AM 8/24/97 -0600, you wrote: >Dave- > Your map is PBR! (pretty bloody remarkable: I figured that would get by >the Yank censors). On one hand, I would like to show the revised map to my supervisor, but >I know he'd say something like: "I don't want you wasting your time on PSN, when you could instead be >making a map like that for my project" > >And I know he wouldn't like my reply: > "I don't do JAVA, sir; I can only do FORTRAN". > >Anyway, Dave, you keep up the good work, and I'll try and focus on getting all the credit. >-Edward > >PS. It nice to know where Montana is after all these years ... I've been wondering ... and otherwise, seeing the relationship of everyone to everyone else makes everthing alot clearer, don't you think? > >PPS. In terms of substantive remarks, it should be "courtesy of NEIC" >not "courtsey of NEIC". > > Co-ordinator: New Zealand PSN Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Karl Cunningham Subject: Re: Map of my 'quakes & FTP'ing Date: Sun, 24 Aug 1997 08:28:50 -0700 Bob & the gang -- For FTPing, another program -- FTP Explorer -- is freeware for home and educational use. See http://www.ftpx.com . Although I haven't used it very much, it seems to have most of the features of WS_FTP, and I find it a little easier to use. WRT the fast upload, I suspect that somewhere on your computer is a buffer for outgoing modem data. Your FTP program sent the data to the buffer in 0.3 sec and then the modem sent it out at its own pace. Karl Cunningham La Mesa, CA. PSN Station #40 karlc@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: shammon1@............. Subject: Re: thanks Date: Sun, 24 Aug 1997 09:29:31 -0700 Be sure to take a few photos as you build it. We want to see it-- Regards, Steve Hammond PSN San Jose Allan Bland wrote: > > from allan bland > THANKS TO ALL FOR INFO ON > LEHMAN SEISMOGRAPH IAM STARTING TO BUILD NOW > WILL LET YOU KNOW IF IT WORKS????. > THANKS AGAIN > ALLAN > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: PSN abstract for AGU: solicitation of comments Date: Sun, 24 Aug 1997 21:39:40 -0600 Jim- Thank you very much for your two pertinent and interesting stories. I may cite them in the presentation (the exact nature of which is not clear at present); would that be OK with you? I have CC'd a copy of your message and my reply to PSN-L because I would like all the members to be informed about this "review" process. -Edward PS. I liked your website. The picture of the farm made me envious that you had such a wonderful place to live with your family where you could also pursue your interests in seismology, astronomy and cosmic rays as well. Jim Hannon wrote: > > Edward, > > I don't have much to say except to say I completely agree with the > statements about sitting ducks and absurdly redundant messages. I have > two stories from personal experience that bring these points home. > > Around here in Iowa the most common natural disaster is a tornado. Some > time ago I belonged to the local amateur radio storm watch team. During > a storm watch the amateur coordinator sits in the county civil defense > headquarters along with the "professionals". Anyway a tornado was > spotted during our wedding rehersal dinner and the hotel sent us all to > the basement. A friend of mine had his handheld radio along and we > listened to the information flowing from the spotters and others at the > civil defense headquarters. We couldn't convince the hotel people that > the all clear had been called until it was announced on the local FM > radio station almost 20 minutes after the fact. The thing that > irritates me most about this is that in this situation the hotel > athorities expected all of us to act like victims when in fact some of > us knew more about what was going on than they did. I like to say that > during a disaster, athorities would like everyone else to "assume the > position" of a victim. > > Another story invloves a fire department. In the Navy I was stationed > in Northern Ireland. One day the mail room on the base caught on fire. > The local fire dept was called. By the time they arrived the fire had > been put out. The fire dept's only comment was: How did you do that?! > What they didn't understand was that all Navy personel get fire fighting > traning and they didn't want to loose any of there mail. > > I hope I didn't bore you too much with my stories. > -- > Jim Hannon > http://soli.inav.net/~jmhannon/ > 42,11.90N 91,39.26W > WB0TXL -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Charlie Rond Subject: Re: PSN abstract for AGU: solicitation of comments Date: Mon, 25 Aug 1997 00:53:27 -0500 Edward, >PSN members- > Below (also attached as a MS Word 6.0/95 document) is the rough draft >of an abstract entitled "Public Seismic Network (PSN): a Model for >Preparing People to use Real-time Information About Natural Hazards" >that we are preparing to submit to the 1997 Fall Meeting of the American >Geophysical Union (AGU) to be held in San Francisco, California, USA, >on 8-12 December 1997 . Very nice job! Good luck with it, and thanks for including all of us. Charlie Rond -\/\--Public Seismic Network-Memphis rond@................ (901) 360-0302 [ free BBS ] http://gandlf.ceri.memphis.edu/~rond http://gandlf.ceri.memphis.edu/~rond/psn _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: PSN abstract for AGU: solicitation of comments Date: Mon, 25 Aug 1997 00:01:21 -0600 Charlie- Do you have a summary of or other info about the Natural Hazards workshop you attended in Colorado last month? -Edward Charlie Rond wrote: > > Edward, > > >PSN members- > > Below (also attached as a MS Word 6.0/95 document) is the rough draft > >of an abstract entitled "Public Seismic Network (PSN): a Model for > >Preparing People to use Real-time Information About Natural Hazards" > >that we are preparing to submit to the 1997 Fall Meeting of the American > >Geophysical Union (AGU) to be held in San Francisco, California, USA, > >on 8-12 December 1997 . > > Very nice job! Good luck with it, and thanks for including all of us. > > Charlie Rond -\/\--Public Seismic Network-Memphis > rond@................ (901) 360-0302 [ free BBS ] > http://gandlf.ceri.memphis.edu/~rond http://gandlf.ceri.memphis.edu/~rond/psn > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Charlie Rond Subject: Re: PSN abstract for AGU: solicitation of comments Date: Mon, 25 Aug 1997 01:11:59 -0500 Edward, > Do you have a summary of or other info about the Natural Hazards >workshop you attended in Colorado last month? I do have the workshop "notebook" and other material. What do you need? Charlie Rond -\/\--Public Seismic Network-Memphis rond@................ (901) 360-0302 [ free BBS ] http://gandlf.ceri.memphis.edu/~rond http://gandlf.ceri.memphis.edu/~rond/psn _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson Subject: Re: Map of my 'quakes Date: Mon, 25 Aug 1997 18:53:40 +1200 Gidday Bob, the map of world events looks great, It will be good to see upgrades every so often as batches of new events are added I have always been interested in software that could plot Lat Long. data on a map but have never found any that could do it. Dave Co-ordinator: New Zealand PSN Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: PSN abstract for AGU: solicitation of comments Date: Mon, 25 Aug 1997 10:22:52 -0600 Karl- Thank you for your response. I think that there are many in the strong ground motion and seismic engineering business who could learn from your comment, "heightening earthquake awareness in the development of building codes and zoning ordinances". -Edward Karl Cunningham wrote: > > Edward -- > > Your abstract posted earlier today to the PSN list is very well done, in my > opinion. > > I feel that the more people are exposed to the inner workings of > earthquakes, the more people will develop a healthy respect for them rather > than an irrational fear. As is stands, the only information most people > get about earthquakes is what they hear in the news about how many people > were killed or made homeless by the latest big one from around the world. > > Education such as this will also be a big step toward heightening > earthquake awareness in the development of building codes and zoning > ordinances. > > Thanks for all of your hard work, Edward. If I can be of any help > whatsoever, please don't hesitate to ask. Good luck with your paper. > > Karl Cunningham > La Mesa, CA. > PSN Station #40 > karlc@....... > > At 11:36 PM 8/23/97 -0600, you wrote: > >PSN members- > > Below (also attached as a MS Word 6.0/95 document) is the rough draft > >of an abstract entitled "Public Seismic Network (PSN): a Model for > >Preparing People to use Real-time Information About Natural Hazards" > >that we are preparing to submit to the 1997 Fall Meeting of the American > >Geophysical Union (AGU) to be held in San Francisco, California, USA, > >on 8-12 December 1997 . > >The abstract will be submitted to Special Session U12: "Hazard > >Mitigation: Use of Real-Time Information" (see below following abstract) > >. > > The authors are myself, Ben Gardner (a USGS volunteer who was editor of > >the 1991 PSN Newsletter and editor and co-author of various other > >PSN/USGS publications), and you, the Public Seismic Network. > > Before submitting the abstract to AGU, I am soliciting your (PSN's) > >comments and criticism of the abstract at the same time I am submitting > >it to my office of the U.S. Geological Survey (USGS) for internal > >review. Though Ben and I and others, and Steve Hammond and Dorothy & > >Jerry Darby and other PSN members have published several PSN > >abstracts/articles before, this is the first time that a rough draft > >will be reviewed by all PSN members (courtesy of Larry Cochrane) prior > >to publication. Please send me your responses ASAP and before Tuesday, > >26 Aug 1997, at which time I will electronically submit the revised > >version to AGU. > > Looking forward to your remarks. > >-Edward > > -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: [Fwd: Re: Sites for TREMOR prototypes] Date: Mon, 25 Aug 1997 12:11:59 -0600 -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". From: Norman Davis WB6SHI Subject: Quake alert via pager. Date: Mon, 25 Aug 1997 07:22:47 I was wondering if anyone here knows of a system that is operating in fresno that alerts you when there is a quake. A couple of friends of mine had the pagers. The system operates through the paging system at the St Agnis Hospital there and He feeds the info out via a number that is displayed that tells the magnitude and bearing and distance. It seemed to work real slick. Norman Davis WB6SHI Email normd@............. Shingle Springs, Ca, USA it ain't local... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: PSN abstract for AGU: solicitation of comments Date: Mon, 25 Aug 1997 13:00:32 -0600 Charlie- I think that material is excellent because, for one thing, it reminds me that I am not the only one thinking about these matters even if my concerns are regarded as somewhat extraneous by my seismological colleagues in this office of the USGS. I don't need anymore of this material in the sort-term for the abstract, but if you could keep me informed of related websites and send me some hardcopy of abstracts, etc., by snail mail, we may be able to use that in our presentation in December. Thank you very much. -Edward Charlie Rond wrote: > > Edward, > > > Is there anything a' propos the abstract that you could send me via > >email? > > I think some of the material on hazard mitigation, policy, etc. might be > helpful. I don't have a scanner at the moment to digitize it. What about > copying it and sending you a packet snail mail? Or are you trying to work > it into the abstract before submitting it? > > I may be at a scanner this afternoon. If you need something SAP, let me know. > > >From the workshop program/schedule: > Plenary Session: PUTTING RESEARCH INTO PRACTICE > Moderator: Barbara Vogt, Oak Ridge Natl Lab > > "The most frequently requested topic for discussion at the annual hazards > workshop is how to put the hazards knowledge we have to work. The panel > will focus on this issue from the perspectives of users, physical and social > scientists, and engineers." > > REMOTE SENSING AND ITS APPLICATION TO ENVIRONMENTAL HAZARDS > Moderator: Michael E. Hodgson, Univ of South Carolina > (Among Discussants: - Eric Anderson, USGS) > "Discussion at last summer's workshop compelled one participant to write, > 'It was clear that there is a large disconnect between the remote sensing > scientists and the decision makers in the hazards community. I doubt if > many remote sensing scientists understand a hazard's cycle; and the use of > data in the response, planning, or mitigation, nor if many hazards managers > understand the resolution characteristics of remote sensing.' This panel > will discuss the use of remote sensing for all aspects of environmental > hazards management." > > COMMUNITY BASED ORGANIZATIONS: THEIR ROLE IN MITIGATION > Moderator: John Sorensen, Oak Ridge Natl. Lab. > (Among Discussants: Charles Rond, CERI, PSN) > "Over the past several years many community based organizations (CBOs) have > been established that focus on various aspects of hazards or emergency > management. Some groups have emerged as political or grassroots movements, > while others have been established through federal or state mandates. This > session will examine the roles and impacts of CBOs with respect to emergency > management at the local level." > > (I stated that PSN was a community based org which began as a grassgroots > movement) > > THE SOCIAL CREATION OF VULNERABILITY > Moderator: John Wiener, Univ of Colorado > Recorder: Roger Pulwarty, Univ of Colorado > "This discussion will examine how societies and cultures create > vulnerability to natural hazards. The difference between socially caused > versus physically caused exposure to risk from hazards will be explored, > with reference to how people have sought to influence policy, and how that > in turn may affecdt outcomes. Discussants will consider why there appears > to be an increasing foreign interest in incorporating vulnerability into > development planning, and they will identify lessons that may be applied in > the U.S. The purpose of the session is to help make the concept of socially > determined vulnerability useful for practitioners as well as academics." > > CONSISTENT INFORMATION FOR WARNINGS: IS IT A PROBLEM? > Moderator: Don Wernly, NOAA/Natl Weather Serv. > "widespread provision of remote sensing data to local decision makers and > the media has resulted in multiple interpretations of hazardous situations > that can result in inconsistent messages being delivered to the public. > This ambiguity can lead to public questioning of official forecast and > warning products and can undermine effective response. The panel will > discuss this situation and elicit views from the audience as to whether this > is a problem and what options are available to maintain effective public > warnings." > > (This focused on weather warnings, but one discussant was Jim Davis, CA Div > of Mines and Geology, who talked about Parkridge and other earthquake > "warnings.") > > ------------------------------------------------- > > Is this what you had in mind? There is more: e.g. THE INTERNET AND COMPUTER > TECHNOLOGY FOR DISASTER AND HAZARD MANAGEMENT: UNANSWERED QUESTIONS, etc. > > Some abstracts might be helpful. > > Let me know. > > Charlie Rond -\/\--Public Seismic Network-Memphis > rond@................ (901) 360-0302 [ free BBS ] > http://gandlf.ceri.memphis.edu/~rond http://gandlf.ceri.memphis.edu/~rond/psn -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: John Hernlund Subject: Re: Quake alert via pager. Date: Mon, 25 Aug 1997 13:14:36 -0700 (MST) On Mon, 25 Aug 1997, Norman Davis WB6SHI wrote: > I was wondering if anyone here knows of a system that is operating in > fresno that alerts you when there is a quake. A couple of friends of mine > had the pagers. The system operates through the paging system at the St > Agnis Hospital there and He feeds the info out via a number that is > displayed that tells the magnitude and bearing and distance. It seemed to > work real slick. What would be really neat is if you are not too close to the epicenter the seismographs all over the place could pick up the waves travelling out from the source and beep you BEFORE the waves arrive. Now that would be slick!!! ****************************************************************************** John Hernlund E-mail: hernlund@....... WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: [Fwd: agu abstract] Date: Mon, 25 Aug 1997 19:59:49 -0600 -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". From: DSeeber101@....... Subject: drum pen info Date: Tue, 26 Aug 1997 01:31:50 -0400 (EDT) Hi I have a friend that built a drum recording seismograph for the Discovery center of Idaho. He has a question about the pens he uses and I'd like to pass it along to PSN for comment and/or ideas. Thank you. Don Sieber dseeber101@....... ------------------------------------------------------------------------------ ------------------------------------------- Don here is the gist of the inquiry about pen systems. At the Discovery Center of Idaho we have been using Pentel's Ceramicron SMR o1 pens with good results for over two years. The $3.00, 0.1mm pens record in excess of 1500 feet of record before running out of ink. Refill of the pens is possible but the reliability is not satisfactory with the inks and techniques we have used. A pen records about twenty days of seismograph results before change is needed. We would be interested in any advice on an ink systems that might be more economical for our application. Butcher paper is used and pen travel,driven by a servo is +-1.5" at a max freq of 1Hz. Thanks for any help..... Don I appreciate your willingness to try to save DCI a buck! Bill _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Charlie Rond Subject: Re: Quake alert via pager. Date: Tue, 26 Aug 1997 05:47:22 -0500 Norman, > I was wondering if anyone here knows of a system that is operating in >fresno that alerts you when there is a quake. A couple of friends of mine >had the pagers. The system operates through the paging system at the St >Agnis Hospital there and He feeds the info out via a number that is >displayed that tells the magnitude and bearing and distance. It seemed to >work real slick. Members of the staff of CERI (Center for Earthquake Research and Information), at the University of Memphis, are paged through a national system operated by the NEIC (National Earthquake Information Center) at Golden, CO. Contact NEIC (303) 273-8500. Charlie Rond -\/\--Public Seismic Network-Memphis rond@................ (901) 360-0302 [ free BBS ] http://gandlf.ceri.memphis.edu/~rond http://gandlf.ceri.memphis.edu/~rond/psn _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Mike Stickney Subject: Re: drum pen info Date: Tue, 26 Aug 97 08:21:53 MDT Don/Bill: I run the Montana network and have 12 channels of data recorded by pen on drums (in addition to computer recording). I have always used Teledyne Brown Engineering (formerly Teledyne Geotech) equipment, including ink pens. The pen arms have a replacable, 65 mm long pen tip with a .003" ink orifice that makes a 0.3 mm ink trace. A one-ounce bottle of ink lasts 9-12 months but the writting tip of the pen typically lasts about 6-8 months before wearing away. Teledyne will re-tip pens for $35 each--new they charge $50. Please feel free to contact me if you have any additional questions. Good luck with your project. By the way, where is the Discovery Center located? -Mike Stickney Montana Bureau of Mines and Geology Butte MT (406) 496-4332 ==================================================== At 01:31 AM 8/26/97 -0400, you wrote: >Hi > >I have a friend that built a drum recording seismograph for the Discovery >center of Idaho. He has a question about the pens he uses and I'd like to >pass >it along to PSN for comment and/or ideas. > >Thank you. > >Don Sieber dseeber101@....... >------------------------------------------------------------------------------ >Don here is the gist of the inquiry about pen systems. >At the Discovery Center of Idaho we have been using Pentel's Ceramicron >SMR o1 pens with good results for over two years. The $3.00, 0.1mm pens >record in excess of 1500 feet of record before running out of ink. >Refill of the pens is possible but the reliability is not satisfactory >with the inks and techniques we have used. A pen records about twenty >days of seismograph results before change is needed. We would be >interested in any advice on an ink systems that might be more economical >for our application. Butcher paper is used and pen travel,driven by a >servo is +-1.5" at a max freq of 1Hz. Thanks for any help..... Don >I appreciate your willingness to try to save DCI a buck! > > Bill _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Charles R. Patton" Subject: Re: time-outs when mailing to PSN mail list Date: Tue, 26 Aug 1997 07:54:37 -0700 JC _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Charles R. Patton" Subject: Re: time-outs when mailing to PSN mail list Date: Tue, 26 Aug 1997 08:06:53 -0700 lahr@................. (Dr. John Lahr (USGS-GI Seismologist)) had Edward Cranswick forward his message because his mailer was timing out. Error message in part was: ----- Transcript of session follows ----- ... Deferred: Connection timed out with psn.quake.net. Will keep trying until message is 5 days old I have been having the same problem for weeks when I try and email from home to the PSN list, but never have had the problem from work. (Which is why I sometimes have had Erich Kern forward my messages on the weekends.) How many other people have had the same problem? If anybody who has would forward the full error message to me at patton@......... I will send them to my server's system administrator, and perhaps we can find a common thread to the problem. I've contacted the sysop several times, but she's not having much luck figuring it out. So maybe we can add more clues to solve this. Thanks, Charles R. Patton _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: gchantler@....... (Gary Chantler) Subject: Pullman quake Date: Tue, 26 Aug 1997 10:46:39 -0800 Hi all, Sorry to re-ask a question but is there a way to convert particle displacement to Say Richter Scale and g-forces. I recall someone sent a table that they calculated. I cant find the formula that Someone sent to me when I asked originally. Seems we had a small quake not far from Pullman. Now everyone going crazy about the reactor here on campus. Turns out that a Peak Displacment of 0.05 cm will scram (over0ride and shut-down) the reactor. Everyone is asking me what this is on the Richter scale and (o.o5 cm) and I cant find the formula in any of my books or old emails. Thanks in advance, Gary *********************************************************** ***************************************** Gary R. Chantler Instructional Tech. II Geology 101 (509) 335-5353 Webster Rm 922 gchantler@....... *#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#* _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson Subject: Re: time-outs when mailing to PSN mail list Date: Wed, 27 Aug 1997 12:37:32 +1200 I haven't yet struck it with the PSN but am more regularly getting that undelivered message when e-mailing to Nth and Central America. Dave At 08:06 AM 8/26/97 -0700, you wrote: >lahr@................. (Dr. John Lahr (USGS-GI Seismologist)) had Edward >Cranswick forward his message because his mailer was timing out. >Error message in part was: > ----- Transcript of session follows ----- > > ... Deferred: Connection timed out with psn.quake.net. > Will keep trying until message is 5 days old >I have been having the same problem for weeks when I try and email from >home to the PSN list, but never have had the problem from work. (Which >is why I sometimes have had Erich Kern forward my messages on the >weekends.) > How many other people have had the same problem? If anybody who has >would forward the full error message to me at patton@......... I will >send them to my server's system administrator, and perhaps we can find a >common thread to the problem. I've contacted the sysop several times, >but she's not having much luck figuring it out. So maybe we can add >more clues to solve this. >Thanks, >Charles R. Patton > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > Co-ordinator: New Zealand PSN Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Jacquie C. Cowe" Subject: test Date: Wed, 27 Aug 1997 09:12:53 -0700 (PDT) test 1 _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Jacquie C. Cowe" Subject: test Date: Wed, 27 Aug 1997 09:13:17 -0700 (PDT) test 1 _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Karl Cunningham Subject: Re: Pullman quake Date: Wed, 27 Aug 1997 10:39:27 -0700 Gary -- The information I have comes from a post made to this list 29 Nov 1996 by John C. Lahr, USGS. From my interpretation of this information, an earthquake 100km away that causes a displacement of 0.05cm peak would be approximately ML6.1 . This is based on the response of a Wood-Anderson Seismograph which has a natural frequency of 1.25 Hz. This is a rather rough approximation, since one should consider the bandwidth of the sensor used at the reactor, site response, and other factors. Hope this helps. Karl Cunningham La Mesa, CA. PSN station #40 karlc@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert L Barns <75612.2635@..............> Subject: Re: Map of my 'quakes Date: Wed, 27 Aug 1997 13:59:41 -0400 Dave Nelson, Most (probably all) computer aided design (CAD) programs will plot x, y= data and connect the x, y points with either a straight line or a curve. = A Mercator projection has latitude linearly proportional to y and longitude= proportional to x so it's just a matter of scaling and setting the origin= of the plot. CAD programs are wonderful tools--there are all sorts from simple ones = up to highly complex (e.g., DesignCAD and AutoCAD, $thousands). DesignCAD (for DOS, ~~$250), for example, has about 230 commands and takes a lot o= f learning although simple stuff can be done after learning only a few. It= includes a (primative) BASIC-like programming language. I used this to d= o my map since it can read data files and plot the points etc., etc. There are also 3-D CAD's which are really wild! www.download.com offers two of the 2-D programs:1. DeltaCAD 2.4 for W= in 95, 1.3 megs and 2. TurboCAD for Win 3.1, 4.8 megs., shareware. I have seen a little of TurboCAD and it looks to be powerful. I'll bet that there are mapping data (outlines of countries, etc.) an= d programs on the Internet. Some experienced web-surfer would do this list= a service by finding some of this stuff. Bob _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: gchantler@....... (Gary Chantler) Subject: Date: Wed, 27 Aug 1997 11:23:55 -0800 >He was the "Saturation Control Rod Axe Man", ie >SCRAM. He would cut the >rope quickly if things got out of hand. Bet >OSHA would love that >position today. >Lou I feel like thats my job around here sometimes. To throw myself on the reactor to save everyone else from having to deal with their mistakes. Is it Friday yet? For any of you T2 fans out there Aug. 29, 1997 is the day the Nuke war is to destroy our civilazation. Good day to watch the movie as it is a friday. Seismic stuff = = = = = = = = = = = = = Seems to me that .05cm = .5mm is quite a bit for a seismic cut-off switch, Esp. for a reactor. Our controll rods are gravity feed. If they don't go down, someone is supposed to go over the catwalk and push them down (stand on them, or what ever). As I understand it, the switch is a long (undetermined length) rod that sits between many contacts that are .1 cm apart. this is information that I just received this morning. I'm not sure with this setup that I (we) can give them the answer they are looking for. Any other thoughts out there? Thanks for the info. thus far, Gary *********************************************************** ***************************************** Gary R. Chantler Instructional Tech. II Geology 101 (509) 335-5353 Webster Rm 922 gchantler@....... *#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#* _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: [Fwd: new PCS coverage map URL] Date: Wed, 27 Aug 1997 17:08:43 -0600 -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". From: Robert L Barns <75612.2635@..............> Subject: Map of your 'quakes Date: Thu, 28 Aug 1997 20:17:15 -0400 Hi gang, I will make a world map of your 'quakes if you send me a , i.e.,= a regular DOS file (not a word processor file) of your latitudes and longitudes. The map will be a Mercator projection centered on the Pacifi= c Ocean. To see what this is like, see my map by doing = ftp://psn.quake.net/incoming and download worlmapr.gif. = The data you should send looks like this: 34.1, 145.7 -44.2, 89.2 47.8, -145.6 etc. (latitude first, then longitude) These are decimal degrees with south latitude and west longitude negative. A comma between lat and lon is required and spaces don't matte= r. 'Quakes close together (e.g., 200 clustered around Redwood City, CA) cause no problem but don't expect to see them as individuals since the do= t size is large enough to show up nicely on the world. Also send whatever you would like (which will appear at the bottom, see my map) <and> the filename you prefer. It's probably a good idea to include dates in the title. If we look at one of these 20 years from now (I'll only be 90), it will make more sense. Send this stuff to me at 75612.2635@.............. so we don't overload Larry's system. I will send your map to psn.quake.net/incoming If you don't like it= , let me know and I will re-do it. After you find your map on the system, you can post a message to the ps= n list with any explanation you like. Bob Barns _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Stephen Caruso <scaruso@......................> Subject: Eastern Mediteranean Topography Date: Thu, 28 Aug 1997 22:15:30 -0400 (EDT) Anybody know where I can find on the web a good digital eastern med. topo map? I have a hard time sleuthing thru the massive files day after day at NOAA. Any hints? Thanks! STEPHEN CARUSO CET KB8UGH _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson <dann@........> Subject: Re: Map of your 'quakes Date: Fri, 29 Aug 1997 14:50:27 +1200 Bob interesting offer, one I an sure will be taken up on....... tell me are you ably to do them of a particular area eg. Nth America, or New Zealand region only so that you see that country in a zoomed in view to give dots better spacing ?? Dave At 08:17 PM 8/28/97 -0400, you wrote: >Hi gang, > I will make a world map of your 'quakes if you send me a <text>, i.e., a >regular DOS file (not a word processor file) of your latitudes and >longitudes. The map will be a Mercator projection centered on the Pacific >Ocean. To see what this is like, see my map by doing >ftp://psn.quake.net/incoming and download worlmapr.gif. > The data you should send looks like this: > > 34.1, 145.7 >-44.2, 89.2 >47.8, -145.6 >etc. (latitude first, then longitude) > > These are decimal degrees with south latitude and west longitude >negative. A comma between lat and lon is required and spaces don't matter. > 'Quakes close together (e.g., 200 clustered around Redwood City, CA) >cause no problem but don't expect to see them as individuals since the dot >size is large enough to show up nicely on the world. > Also send whatever <title> you would like (which will appear at the >bottom, see my map) <and> the filename you prefer. It's probably a good >idea to include dates in the title. If we look at one of these 20 years >from now (I'll only be 90), it will make more sense. > Send this stuff to me at 75612.2635@.............. so we don't >overload Larry's system. > I will send your map to psn.quake.net/incoming If you don't like it, >let me know and I will re-do it. > After you find your map on the system, you can post a message to the psn >list with any explanation you like. >Bob Barns > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > Co-ordinator: New Zealand PSN Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson <dann@........> Subject: Re: Eastern Mediteranean Topography Date: Fri, 29 Aug 1997 14:53:37 +1200 are you after something like I have at http://psn.quake.net/dave/eu.htm or are you after something larger scale ?? Dave At 10:15 PM 8/28/97 -0400, you wrote: >Anybody know where I can find on the web a good digital eastern med. topo >map? I have a hard time sleuthing thru the massive files day after day at >NOAA. Any hints? Thanks! > >STEPHEN CARUSO CET >KB8UGH > > > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > Co-ordinator: New Zealand PSN Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Mustafa Erdik <erdik@.....................> Subject: Re: Eastern Mediteranean Topography Date: Fri, 29 Aug 1997 06:04:52 +0100 TRY http://atlas.geo.cornell.edu Best regards, Mustafa Erdik At 10:15 PM 8/28/97 -0400, you wrote: >Anybody know where I can find on the web a good digital eastern med. topo >map? I have a hard time sleuthing thru the massive files day after day at >NOAA. Any hints? Thanks! > >STEPHEN CARUSO CET >KB8UGH > > > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > Mustafa Erdik Professor and Chair, Department of Earthquake Engineering Kandilli Observatory and Earthquake Engineering Bogazici University 81220 Cengelkoy, Istanbul, Turkey e-mail: erdik@..................... mustafa@.................... Fax: +90.216.308.0163, +90.216.332.1711 Tel: (Bus.) +90.216.332.6560, +90.216.332.9701 (Home) +90.216.339.8633 _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick <cranswick@........> Subject: Revised PSN AGU abstract Date: Fri, 29 Aug 1997 22:33:45 -0600 PSN Members- Below and attached is the revised PSN AGU abstract that was submitted to AGU today. I am grateful to everyone for the inspiration that the PSN has provided and continues to provide. Ben Gardner and I want to thank Karl Cunningham, Jim Hannon, John Lahr, and Charlie Rond in particular, and also Art Frankel, the internal USGS reviewer, for their specific comments/criticisms of the draft version of the abstract. The abstract has been changed in response to their input. The next step is to prepare for the actual presentation at the AGU meeting in December. Other than the plan to have a real-time display of PSN websites at the presentation, it is all rather up-in-the-air otherwise, so suggestions are welcome! I will be out of the office until 8 September. Thank you again. -Edward ************************************************************************ Public Seismic Network (PSN): a Model for Preparing People to use Real-time Information About Natural Hazards Edward Cranswick and Benjamin Gardner (U.S. Geological Survey, MS 966, Box 25046, Federal Center, Denver, CO 80225, USA; 303-273-8609; cranswick@......... Public Seismic Network (http://psn.quake.net/, psn-l@.............. When an earthquake occurs, unlike any other natural hazard, every individual in the population at risk is aware within seconds that a dangerous event has happened. Without the aid of any technology, the consciousness of everyone affected is almost instantaneously focused on the same subject. Instead of soliciting that information, authorities broadcast the redundant message that an earthquake has occurred. A program of monitoring natural hazards for the public requires public participation to effectively mitigate those hazards. The Public Seismic Network (PSN), rather than relegating them to the role of sitting ducks waiting to be devastated by the unexpected, enables people to become aware that earthquakes are part of normal, on-going Earth processes. The PSN is a rapidly growing international group of amateur seismologists, concentrated in California, who record earthquakes with their own digital seismographs and exchange waveform time series and communicate with each other via the Internet. At present, the PSN consists of about 50 seismograph stations, about 250 subscribers to its email list server, and about 10 websites. In urban areas of high seismic risk, a grassroots organization like the PSN -- equipped with low-cost, mass-produced, standardized strong-motion seismographs -- could vastly increase the spatial density of sampling ground motions. This organization would form a constituency of well-informed residents who not only know how to respond to catastrophic earthquakes but also support hazard mitigation programs in the community. Rather than just building faster ambulances to mitigate the impact of heart attacks, it is more effective to modify the public habits of exercise and diet. The PSN is a model for using technology to connect human awareness to, rather than shield it from, the environment. -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". From: JIM CRISTIANO <weitech@..........> Subject: Re: Geophones Date: Sat, 30 Aug 1997 21:15:11 -0700 Doug Crice wrote: > Exploration geophones are normally damped at 0.7 (sometimes a little > less) with a resistor to get a relatively flat frequency response. > Critical damping means you don't get any oscillations. The > manufacturer's data sheets have curves for various combinations. Over > damping cuts the response at the low ends and also lowers the output > because the coil resistance (say 500 ohms) and the damping resistor make > a voltage divider. Hello, Did anyone catch the implication of Doug's comment on using a shunt resistor on a geophone to achieve critical damping? If it works on a geophone, why not a coil/magnet sensor? I looked in my GeoSpace data sheets and saw that the graphs show different damping with different values of shunt resistors. Without a shunt resistor, the graph looks like a high pass filter with a peak at the natural period. With a shunt resistor, the frequency response is flat from the natural period on up. Now... I can understand how the added resistor and coil form a voltage divider and would attenuate the output..... but I would think the frequency response would remain the same. I talked to a eng. at Geospace, hoping he could shed some light on the subject but things fell apart when he got to the BIG resistors on top of diesel locomotives. I guess the question is..... How can adding a shunt resistor to the coil dampen the mechanical natural frequency of the magnet mounted on a spring? Doug? Any ideas? Thanks, Jim cristiano@........... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Al Allworth <aallworth@........> Subject: Re: Geophones Date: Sat, 30 Aug 1997 23:48:16 -0700 At 09:15 PM 8/30/97 -0700, you wrote: >Doug Crice wrote: > >> Exploration geophones are normally damped at 0.7 (sometimes a little >> less) with a resistor to get a relatively flat frequency response. >> Critical damping means you don't get any oscillations. The >> manufacturer's data sheets have curves for various combinations. Over >> damping cuts the response at the low ends and also lowers the output >> because the coil resistance (say 500 ohms) and the damping resistor make >> a voltage divider. > > Hello, > Did anyone catch the implication of Doug's comment on using a shunt > resistor on a geophone to achieve critical damping? If it works on a > geophone, why not a coil/magnet sensor? > > I looked in my GeoSpace data sheets and saw that the graphs show > different damping with different values of shunt resistors. Without > a shunt resistor, the graph looks like a high pass filter with a peak > at the natural period. With a shunt resistor, the frequency response > is flat from the natural period on up. > > Now... I can understand how the added resistor and coil form a > voltage divider and would attenuate the output..... but I would > think the frequency response would remain the same. > > I talked to a eng. at Geospace, hoping he could shed some light on > the subject but things fell apart when he got to the BIG resistors > on top of diesel locomotives. > > I guess the question is..... How can adding a shunt resistor to the > coil dampen the mechanical natural frequency of the magnet mounted > on a spring? > > Doug? Any ideas? > > Thanks, > Jim cristiano@........... > > Hi Jim, To put it quite simply, the geophone is a generator, converting mechanical energy into electrical energy into electrical energy. The lower resistance placed across the output, the more quickly the stored energy in the mass of the of the magnet is converted into heat in the load resistor. The resistance of the coil always appears as a resistance in series with the generator and limits the damping effect. In other words even shorted out only a certain degree of damping can be achieved. The geophones are designed with the internal resistance arranged so that a useful amount of output will be available with the correct amount of damping. ____________________________________________________________________________ Al Allworth, Gold Beach, OR aallworth@........ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Tolga BEKLER <bekler@...........> Subject: Re: Eastern Mediteranean Topography Date: Sun, 31 Aug 1997 12:29:30 +0400 (MEDT) Try also NOAA Data center web page Tolga Bekler Kandilli Obs. & E/Q Res Inst On Fri, 29 Aug 1997, Mustafa Erdik wrote: > TRY http://atlas.geo.cornell.edu > > Best regards, > Mustafa Erdik > > > > At 10:15 PM 8/28/97 -0400, you wrote: > >Anybody know where I can find on the web a good digital eastern med. topo > >map? I have a hard time sleuthing thru the massive files day after day at > >NOAA. Any hints? Thanks! > > > >STEPHEN CARUSO CET > >KB8UGH > > > > > > > >_____________________________________________________________________ > > > >Public Seismic Network Mailing List (PSN-L) > > > >To leave this list email listserver@............. with the body of the > >message: leave PSN-L > > > > > Mustafa Erdik > Professor and Chair, Department of Earthquake Engineering > Kandilli Observatory and Earthquake Engineering > Bogazici University > 81220 Cengelkoy, Istanbul, Turkey > > e-mail: erdik@..................... > mustafa@.................... > > Fax: +90.216.308.0163, +90.216.332.1711 > Tel: (Bus.) +90.216.332.6560, +90.216.332.9701 > (Home) +90.216.339.8633 > > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jim Hannon <jmhannon@........> Subject: Re: Geophones Date: Sun, 31 Aug 1997 10:53:06 -0500 Al Allworth wrote: > > At 09:15 PM 8/30/97 -0700, you wrote: > >Doug Crice wrote: > > > >> Exploration geophones are normally damped at 0.7 (sometimes a little > >> less) with a resistor to get a relatively flat frequency response. > >> Critical damping means you don't get any oscillations. The > >> manufacturer's data sheets have curves for various combinations. Over > >> damping cuts the response at the low ends and also lowers the output > >> because the coil resistance (say 500 ohms) and the damping resistor make > >> a voltage divider. > > > > Hello, > > Did anyone catch the implication of Doug's comment on using a shunt > > resistor on a geophone to achieve critical damping? If it works on a > > geophone, why not a coil/magnet sensor? > > > > I looked in my GeoSpace data sheets and saw that the graphs show > > different damping with different values of shunt resistors. Without > > a shunt resistor, the graph looks like a high pass filter with a peak > > at the natural period. With a shunt resistor, the frequency response > > is flat from the natural period on up. > > > > Now... I can understand how the added resistor and coil form a > > voltage divider and would attenuate the output..... but I would > > think the frequency response would remain the same. > > > > I talked to a eng. at Geospace, hoping he could shed some light on > > the subject but things fell apart when he got to the BIG resistors > > on top of diesel locomotives. > > > > I guess the question is..... How can adding a shunt resistor to the > > coil dampen the mechanical natural frequency of the magnet mounted > > on a spring? > > > > Doug? Any ideas? > > > > Thanks, > > Jim cristiano@........... > > > > > Hi Jim, > > To put it quite simply, the geophone is a generator, converting mechanical > energy into electrical energy into electrical energy. The lower resistance > placed across the output, the more quickly the stored energy in the mass of > the of the magnet is converted into heat in the load resistor. The > resistance of the coil always appears as a resistance in series with the > generator and limits the damping effect. In other words even shorted out > only a certain degree of damping can be achieved. The geophones are designed > with the internal resistance arranged so that a useful amount of output will > be available with the correct amount of damping. > ____________________________________________________________________________ > > Al Allworth, Gold Beach, OR aallworth@........ > > _____________________________________________________________________ > > The problem with using resistive damping with the typical Lehman coil magnet sensor is that the magnetic circuit is not as efficient as in the geophone. This means that even with a short circuit it may not achieve the desired damping. -- Jim Hannon http://soli.inav.net/~jmhannon/ 42,11.90N 91,39.26W WB0TXL _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Ray <rayv@................> Subject: PCL 711 Date: Mon, 01 Sep 1997 10:34:03 -0400 I am trying to get a PCL 711 running with SDR. The SDR software wants an IRQ which it does not appear the 711 requires. Any hints on getting the 711 up and running would be helpful. thanks. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane <cochrane@..............> Subject: Re: PCL 711 Date: Mon, 01 Sep 1997 12:37:22 -0700 At 10:34 AM 9/1/97 -0400, you wrote: >I am trying to get a PCL 711 running with SDR. The SDR software wants an >IRQ which it does not appear the 711 requires. Any hints on getting the >711 up and running would be helpful. thanks. The card must generate an interrupt from the pacing circuitry on the board. Very old cards may not have this feature. Newer cards had a jumper to set the IRQ number and the current cards use software to set the IRQ number. If the card is very old and does not have the pacer stuff then it will not work with SDR. If it has interrupt IRQ jumpers then you must set it to a free interrupt on your system like IRQ5. If it is a new board with the pacer stuff but no IRQ jumpers then SDR will set/program the IRQ you selected when you first started the program. You can change/try another IRQ but deleting the SDR.INI file and restarting SDR. Hope this helps.... -Larry Cochrane Redwood City, PSN > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Stephen Caruso <scaruso@......................> Subject: 386pal laser mem config Date: Mon, 1 Sep 1997 17:17:37 -0400 (EDT) I have a 386 laser pal version I have to set dipswitches on to upgarde memory for dedicate data acq computer. Anybody familiar w/this model? Thanks for the respones on the Mediterranean topo. If any body finds it off hand can you send it to me at scaruso@...................... as an attachment? , as a tiff or gif file? STEPHEN CARUSO CET KB8UGH _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert L Barns <75612.2635@..............> Subject: Re: Map of your 'quakes Date: Tue, 2 Sep 1997 13:53:26 -0400 Dave, = Sorry, the only map I can do easily is of the whole world. Selected areas would be a lot of work but if the current offer doesn't kill me, maybe I'll try a few of those. I'll let you know when I'm ready for that exercise. Bob Barns _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Karl Cunningham <karlc@.......> Subject: Pullman quake Date: Wed, 03 Sep 1997 10:56:23 -0700 The following is a forwarded message from Dr. John Lahr -- > >Karl, > >I was away from the office last week, so didn't read the question >from Gary on magnitude until today. Thanks for your answer. > >I've put information on Richter magnitude on my web site, at: > > http://www.giseis.alaska.edu/Input/lahr/richter.html > >which Gary and others may find useful. > >Could you please forward this message to the psn (for some reason >I can receive but not send psn messages). > >Thanks, >JCLahr > >################################## John C. Lahr >################################# Seismologist >################################ U.S. Geological Survey >############################### c/o Geophysical Institute >############################## 903 Koyukuk Drive >~~~~~~~~~~~~~~ Get ~~~~~~~~~~ ############################# >########################################################### > P.O. Box 757320 ################################ > Fairbanks, AK 99775 ################################# > Phone: (907) 474-7997 ################################## > Fax: (907) 474-5618 ~~~~~~~~ the thrust? ~~~~~~~~~~~~~~ > lahr@........ #################################### > http://www.aeic.alaska.edu/Input/lahr/ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Dick Morgret <wizard@.........> Subject: U.S.G.S. location Date: Wed, 03 Sep 1997 16:59:31 -0700 To whom etc. I would like to go to the U.S.G.S. open house on the 13th but do'nt know how to get there. Can anyone give me an address and directions? I live in Hayward. Thanks, Dick Morgret _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Ray <rayv@................> Subject: Re: PCL 711 Date: Wed, 03 Sep 1997 22:07:23 -0400 my 711 is obviously one of the early ones. do you still have your three channel a/d boards? i would like to order one. would like the 16 bit version. also would like the stabilized osc and wwv circuitry if poss. thanks. ray. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Ray <rayv@................> Subject: Re: PCL 711 Date: Wed, 03 Sep 1997 22:09:08 -0400 ment to just send my last message to larry cochrane. pls ignore. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: shammon1@............. Subject: Re: U.S.G.S. location Date: Wed, 03 Sep 1997 23:13:05 -0700 Dick the USGS is on Middlefield Road in Menlo Park. Come across the bay from Hayward to Foster City and go south on 101 to University Ave. in E. Palo Alto. Go west on University to Middlefield Road. Middlefiled runs between 101 and El Camino. Go north on Middlefield and watch for the signs. The USGS is on the left side across from the fire station. The complex covers a few blocks. Regards, Steve Hammond Dick Morgret wrote: > > To whom etc. > I would like to go to the U.S.G.S. open house on the 13th but do'nt know > how to get there. Can anyone give me an address and directions? I live > in Hayward. > Thanks, > Dick Morgret > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert L Barns <75612.2635@..............> Subject: Re: PCL 711 Date: Thu, 4 Sep 1997 21:23:31 -0400 Ray V, I infer from your bellatlantic service provider that you may be nearby.= = I'm in Berkeley Heights, NJ about 20 miles due west of the Statue of Liberty. If you are in this area, we should get acquainted. People with an interest in am. seismology are scarce here--I know of only one other seismograph station in NJ. It is in Oakland. = My 'phone no. is 908-464-6785. Bob Barns = _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jean-Yves Trudel <jtrudel@.........> Subject: Test Date: Mon, 08 Sep 1997 12:48:29 -0700 test 1 -2 -3! Just to see if it works, Jean-Yves _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jean-Yves Trudel <jtrudel@.........> Subject: activity Date: Mon, 08 Sep 1997 13:13:31 -0700 Hi list! Is it possible that nobody was active on the list since 09-04-97, last post was from Robert L Barns. or maybe I had a problem with my "acica" sever. Is somebody can tell me how many post approx I have lost after Robert L Barns (21:33) Tks! Jean-Yves _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: JIM CRISTIANO <weitech@..........> Subject: Re: activity Date: Mon, 08 Sep 1997 12:35:28 -0700 Jean-Yves Trudel wrote: > Is it possible that nobody was active on the list since 09-04-97, last > post was from Robert L Barns. > > or maybe I had a problem with my "acica" sever. Is somebody can tell me > how many post approx I have lost after Robert L Barns (21:33) Jean-Yves, I think that it's the first option. Every once-in-awhile, in the great cosmic cycle of the universe, no one has anything to say! (:~}- Jim cristiano@........... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jean-Yves Trudel <jtrudel@.........> Subject: Re: activity Date: Mon, 08 Sep 1997 17:40:19 -0700 JIM CRISTIANO wrote: > > Jean-Yves Trudel wrote: > > > Is it possible that nobody was active on the list since 09-04-97, last > > post was from Robert L Barns. > > > > or maybe I had a problem with my "acica" sever. Is somebody can tell me > > how many post approx I have lost after Robert L Barns (21:33) > > Jean-Yves, > > I think that it's the first option. Every once-in-awhile, in the > great cosmic cycle of the universe, no one has anything to say! (:~}- > > Jim cristiano@........... > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L Hi Jim, that means I'm ok Tks! Jean-Yves _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Nick & Sophie Caporossi <nickcap@.............> Subject: Re: Test And retest Date: Mon, 08 Sep 1997 22:35:13 -0400 Yes It's working!!!! Maybe the ground is not shaking that much in the first part of September. Although there has been a couple of 5 Magnitudes in the PAKISTAN and SOUTHWEST INDIAN RIDGE Nick Caporossi At 12:48 PM 9/8/97 -0700, you wrote: >test 1 -2 -3! >Just to see if it works, > >Jean-Yves > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz <gbl@.......> Subject: local event Date: Mon, 08 Sep 1997 08:36:09 -0700 Hi All Just an unusual occurance to report. Between 14 & 18 UTC today I recorded 5 events that pegged my sensor. The unusual part is they are very close (40km or less). I'm at 39.23N & 121.07W. I'll sent one or two when compiled. Barry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jeff Batten <batten@...............> Subject: Test Date: Tue, 9 Sep 1997 13:25:03 -0700 (PDT) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: JIM CRISTIANO <weitech@..........> Subject: Re: Test Date: Tue, 09 Sep 1997 16:02:11 -0700 Jeff Batten wrote: > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L Yeah, the silence is deafening. Jim cristiano@........... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Dick Morgret <wizard@.........> Subject: Re: Test Date: Tue, 09 Sep 1997 17:28:53 -0700 JIM CRISTIANO wrote: > > Jeff Batten wrote: > > > > _____________________________________________________________________ > > > > Public Seismic Network Mailing List (PSN-L) > > > > To leave this list email listserver@............. with the body of the > > message: leave PSN-L > > Yeah, the silence is deafening. > > Jim cristiano@........... > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L I admire a man who speaks his mind. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Walter Williams" <dfheli@..............> Subject: Re: local event & Event Date Date: Tue, 9 Sep 1997 19:23:25 +0000 Hello Barry Lotz, I notice in your e-mail that you said 'today' and yet your e-mail was broadcast by the PSN-L list server on the 9th (at least that is the date I received the message). Your e-mail header info indicates you sent the message on the 8th? What date did your instrument register the events you mention in your posting to the PSN-L? Thank You, Walt Williams, 97.09.09 Canoga Park, California USA dfheli@.............. ==================== Forward ===================== On 8 Sep 97 at 8:36, barry lotz wrote: Date: Mon, 08 Sep 1997 08:36:09 -0700 From: barry lotz <gbl@.......> Reply-to: PSN-L Mailing List <psn-l@.............> Organization: cel To: psn-l@............. Subject: local event Hi All Just an unusual occurance to report. Between 14 & 18 UTC today I recorded 5 events that pegged my sensor. The unusual part is they are very close (40km or less). I'm at 39.23N & 121.07W. I'll sent one or two when compiled. Barry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jeff Batten <batten@...............> Subject: Need a interface for a laptop to CMG-40T Date: Wed, 10 Sep 1997 09:24:32 -0700 (PDT) Hello, I need to display the signal from a broadband seismometer (CMG-40T) on my laptop computer (Toshiba Tecra 586) without any processing delay. I have tried to use Quanterra's software that plots the data from a Q4128 as the packets of data are transmitted. The problem is that there is a delay of up to a minute before the signal is displayed. This makes it difficult to establish cause and effect. For the TriNet project I am trying to locate the CMG-40T in urban environments that are very noisy. People walking around near the sensor, cars driving by on nearby roads, etc. I need to be able to set down the CM-40T at different places, look at the signal (trace on the screen), and try to find the best location in a building, or site. The signal need to be displayed without delay. I would also like to log the data to the hard disk. The output from the sensor is +-10 Volts, differential output. 3 axis. I am looking at purchasing a interface form National Instruments, that uses their Lab view software. The interface plugs into the PCMIA slot. 16 bits. I do need the ability to do some digital filtering of the signal. If anyone knows of any other companies that have a similar interface and software that could do the job, please let me know. Or any recommendations, or comments about LabView. Thanks _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jim Hannon <jmhannon@........> Subject: Re: Need a interface for a laptop to CMG-40T Date: Wed, 10 Sep 1997 12:43:21 -0500 Jeff Batten wrote: > > Hello, > > I need to display the signal from a broadband seismometer (CMG-40T) on my > laptop computer (Toshiba Tecra 586) without any processing delay. I have > tried to use Quanterra's software that plots the data from a Q4128 as the > packets of data are transmitted. The problem is that there is a delay of up > to a minute before the signal is displayed. This makes it difficult to > establish cause and effect. > > For the TriNet project I am trying to locate the CMG-40T in urban > environments that are very noisy. People walking around near the sensor, > cars driving by on nearby roads, etc. > > I need to be able to set down the CM-40T at different places, look at the > signal (trace on the screen), and try to find the best location in a > building, or site. The signal need to be displayed without delay. > I would also like to log the data to the hard disk. > > The output from the sensor is +-10 Volts, differential output. 3 axis. > > I am looking at purchasing a interface form National Instruments, that uses > their Lab view software. > The interface plugs into the PCMIA slot. 16 bits. > > I do need the ability to do some digital filtering of the signal. > > If anyone knows of any other companies that have a similar interface and > software that could do the job, please let me know. Or any recommendations, > or comments about LabView. > > Thanks > Jeff, We use LabView at work with a variety of National Instruments cards. It works quite well for our automated factory test stations. the only reservation I have is that the cards and software tend to be more expensive than I think they should be. -- Jim Hannon http://soli.inav.net/~jmhannon/ 42,11.90N 91,39.26W WB0TXL _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick <cranswick@........> Subject: Re: Need a interface for a laptop to CMG-40T Date: Wed, 10 Sep 1997 11:46:21 -0600 Jeff- In 1994, I got a slick little A/D that output directly into the parallel port and a slick little piece of software that did a realtime display. The company, Dataq Instruments, Inc., provided this as a little demo package for $50. I left the A/D with Steve Hammond of the San Jose PSN for a PSN/USGS project with the local schools that we were thinking of doing then. The company website is http://www.dataq.com/ , and I am sure that they must have some new products that might work. Also I forwarded your email to Robert Banfill <r_banfill@..........> of RefTek Instruments because he has written a slick piece of code for realtime display on a PC of data recorded to a DAS, but you need a DAS to use it. However, you probably can get a DAS for your TriNet site investigations (IRIS PASSCAL also has some similar software for DASs but it requires a UNIX/LINUX platform). Let us know. Good luck! -Edward Jeff Batten wrote: > > Hello, > > I need to display the signal from a broadband seismometer (CMG-40T) on my > laptop computer (Toshiba Tecra 586) without any processing delay. I have > tried to use Quanterra's software that plots the data from a Q4128 as the > packets of data are transmitted. The problem is that there is a delay of up > to a minute before the signal is displayed. This makes it difficult to > establish cause and effect. > > For the TriNet project I am trying to locate the CMG-40T in urban > environments that are very noisy. People walking around near the sensor, > cars driving by on nearby roads, etc. > > I need to be able to set down the CM-40T at different places, look at the > signal (trace on the screen), and try to find the best location in a > building, or site. The signal need to be displayed without delay. > I would also like to log the data to the hard disk. > > The output from the sensor is +-10 Volts, differential output. 3 axis. > > I am looking at purchasing a interface form National Instruments, that uses > their Lab view software. > The interface plugs into the PCMIA slot. 16 bits. > > I do need the ability to do some digital filtering of the signal. > > If anyone knows of any other companies that have a similar interface and > software that could do the job, please let me know. Or any recommendations, > or comments about LabView. > > Thanks > > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz <gbl@.......> Subject: Re: Need a interface for a laptop to CMG-40T Date: Wed, 10 Sep 1997 07:32:43 -0700 Jeff I build several data acquisition systems using info written by Jan Axelson (Micro Computer Journal), but this involves hardware construction. Her info is very helpful to understand the parallel & serial port configuration. I also have a catalogue from ComputerBoards,Inc ( info@.................. )which has a 16 channel single ended or 8 channel differential input 16 bit(100KHz) PCMCIA card for $500. I was considering getting this for work.I don't know anything about it but the price is right. Barry Jeff Batten wrote: > > Hello, > > I need to display the signal from a broadband seismometer (CMG-40T) on my > laptop computer (Toshiba Tecra 586) without any processing delay. I have > tried to use Quanterra's software that plots the data from a Q4128 as the > packets of data are transmitted. The problem is that there is a delay of up > to a minute before the signal is displayed. This makes it difficult to > establish cause and effect. > > For the TriNet project I am trying to locate the CMG-40T in urban > environments that are very noisy. People walking around near the sensor, > cars driving by on nearby roads, etc. > > I need to be able to set down the CM-40T at different places, look at the > signal (trace on the screen), and try to find the best location in a > building, or site. The signal need to be displayed without delay. > I would also like to log the data to the hard disk. > > The output from the sensor is +-10 Volts, differential output. 3 axis. > > I am looking at purchasing a interface form National Instruments, that uses > their Lab view software. > The interface plugs into the PCMIA slot. 16 bits. > > I do need the ability to do some digital filtering of the signal. > > If anyone knows of any other companies that have a similar interface and > software that could do the job, please let me know. Or any recommendations, > or comments about LabView. > > Thanks > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick <cranswick@........> Subject: [Fwd: Sites for TREMOR prototypes--decision time] Date: Thu, 11 Sep 1997 11:39:58 -0600 -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". From: barry lotz <gbl@.......> Subject: local events Date: Thu, 11 Sep 1997 07:32:29 -0700 Hi All Well in the last 12 hours I got 48+ additional atypical local events. I have included two of the typical ones. Barry From: Edward Cranswick <cranswick@........> Subject: Re: local events Date: Thu, 11 Sep 1997 21:38:05 -0600 Barry- Have you've been having any thunderstorms near you. -Edward barry lotz wrote: > > Hi All > Well in the last 12 hours I got 48+ additional atypical local events. > I have included two of the typical ones. -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick <cranswick@........> Subject: Sites for TREMOR prototypes & USGS Open House Date: Thu, 11 Sep 1997 22:06:27 -0600 PSN Members in the San Francisco Bay Area- Below is an included email message I received from John Evans, USGS Menlo Park, about plans for his TREMOR project (see the second included email message from him on the same subject that I forwarded to the PSN-L earlier today). If you are interested in participating in the TREMOR project, please contact him via email <evans@....................> and/or go to the USGS Open House this Saturday & Sunday (13-14 September) at Menlo Park <http://online.wr.usgs.gov/openhouse/> and see his presentation and talk to him in person. At the bottom, I have also included Steve Hammond's (San Jose PSN) email that gives directions on how to get to the USGS Menlo Park. Have a good time! -Edward %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Subject: Re: [Fwd: Sites for TREMOR prototypes--decision time] Date: Thu, 11 Sep 97 11:38:53 PDT From: evans@.................... (John Evans) To: "Edward Cranswick, Lakewood, CO "<cranswick@..................> CC: evans@.................... Edward, I'll be e-mailing something to PSN, but probably next week--just TOO wild out here this week. You might pass on now, in addition to the geography that is already out there: Need a grade-level slab out of the weather with one power plug (~16 Watts). Should not be adjacent to a washing machine or other large motor. A garage is usually ideal. Will use about 18" by 30" by 18" high area, plus a small transmitter up in the rafters. Duration indefinite (i.e., as long as they will have us!). Start time is about one month hence. With thanks, John John Evans wrote: %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Subject: Sites for TREMOR prototypes--decision time Date: Thu, 11 Sep 97 10:06:49 PDT From: evans@.................... (John Evans) To: spudich@.................... ellswrth@.................... oppen@.................... lahr@.................. cranswick@................... dboore@.................... joyner@.................. boat@.................. ward@.................... celebi@.................. jfletcher@.................. CC: evans@..................... jandrews@.................. Y'all, Discussions with various of you and finding out what K2-class instruments will be available has led to the following tentative site choice for the TREMOR prototypes: A two-dimensional array augmenting four of Joe Fletcher's new PG&E FBA-23/RefTeks in the region between his sites at Lexington Reservoir, Stevens Creek Reservoir, deep bay mud in Palo Alto, and moderately deep bay mud in Sunnyvale (Marion's house, in fact). This quadrilatteral includes my own home in unincorporated Cupertino on Pleistocene seds on the hanging wall about one block south of the Cascade Fault ... Two TREMOR prototypes will be cosited with RefTeks and the other four will fill in the quadrilatteral. A 2-D array allows us to make maps with these data--one of the goals for TREMOR-class instruments. Unless there is objection, I will advertise for volunteers from that region at the Open House. My long-term goal for TREMOR/SOS (>>10^3 sites) would require use of private homes and schools in some mix--the same mix we will be hosting in the next three days. Though we might be able to fill out the prototype array with other USGS employees' homes, I think it would be valuable to get relevant real-world maintenance experience as well as the public exposure it might bring. Many thanks for your input, John %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Subject: Re: U.S.G.S. location Date: Wed, 03 Sep 1997 23:13:05 -0700 From: shammon1@............. Reply-To: PSN-L Mailing List <psn-l@.............> To: PSN-L Mailing List <psn-l@.............> References: 1 Dick the USGS is on Middlefield Road in Menlo Park. Come across the bay from Hayward to Foster City and go south on 101 to University Ave. in E. Palo Alto. Go west on University to Middlefield Road. Middlefiled runs between 101 and El Camino. Go north on Middlefield and watch for the signs. The USGS is on the left side across from the fire station. The complex covers a few blocks. Regards, Steve Hammond Dick Morgret wrote: > > To whom etc. > I would like to go to the U.S.G.S. open house on the 13th but do'nt know > how to get there. Can anyone give me an address and directions? I live > in Hayward. > Thanks, > Dick Morgret > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: gchantler@....... (Gary Chantler) Subject: Re: local events Date: Fri, 12 Sep 1997 09:52:33 -0800 >Hi All > Well in the last 12 hours I got 48+ additional atypical local events. >I have included two of the typical ones. > Barry > Do you have gravel pits in your area. They're blasting like crazy up here! Looks pretty similar on the seismogram too. GRC *********************************************************** ***************************************** Gary R. Chantler Instructional Tech. II Geology 101 (509) 335-5353 Webster Rm 922 gchantler@....... *#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#* _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jeff Batten <batten@...............> Subject: Re: Need a interface for a laptop to CMG-40T Date: Fri, 12 Sep 1997 10:48:35 -0700 (PDT) At 12:43 PM 9/10/97 -0500, you wrote: >Jeff Batten wrote: >> >> Hello, >> >> I need to display the signal from a broadband seismometer (CMG-40T) on my >> laptop computer (Toshiba Tecra 586) without any processing delay. I have >> tried to use Quanterra's software that plots the data from a Q4128 as the >> packets of data are transmitted. The problem is that there is a delay of up >> to a minute before the signal is displayed. This makes it difficult to >> establish cause and effect. >> >> For the TriNet project I am trying to locate the CMG-40T in urban >> environments that are very noisy. People walking around near the sensor, >> cars driving by on nearby roads, etc. >> >> I need to be able to set down the CM-40T at different places, look at the >> signal (trace on the screen), and try to find the best location in a >> building, or site. The signal need to be displayed without delay. >> I would also like to log the data to the hard disk. >> >> The output from the sensor is +-10 Volts, differential output. 3 axis. >> >> I am looking at purchasing a interface form National Instruments, that uses >> their Lab view software. >> The interface plugs into the PCMIA slot. 16 bits. >> >> I do need the ability to do some digital filtering of the signal. >> >> If anyone knows of any other companies that have a similar interface and >> software that could do the job, please let me know. Or any recommendations, >> or comments about LabView. >> >> Thanks >> >Jeff, > >We use LabView at work with a variety of National Instruments cards. It >works quite well for our automated factory test stations. the only >reservation I have is that the cards and software tend to be more >expensive than I think they should be. > >-- >Jim Hannon >http://soli.inav.net/~jmhannon/ >42,11.90N 91,39.26W >WB0TXL > > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > Jim, thanks for the info. I am going to go with Labview. Thanks _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jeff Batten <batten@...............> Subject: Re: Need a interface for a laptop to CMG-40T Date: Fri, 12 Sep 1997 10:50:34 -0700 (PDT) At 07:32 AM 9/10/97 -0700, you wrote: >Jeff > I build several data acquisition systems using info written by Jan >Axelson (Micro Computer Journal), but this involves hardware >construction. Her info is very helpful to understand the parallel & >serial port configuration. I also have a catalogue from >ComputerBoards,Inc ( info@.................. )which has a 16 channel >single ended or 8 channel differential input 16 bit(100KHz) PCMCIA card >for $500. I was considering getting this for work.I don't know anything >about it but the price is right. > Barry Barry, Thanks for the info. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane <cochrane@..............> Subject: Re: local events Date: Fri, 12 Sep 1997 11:46:53 -0700 Hi Barry, Please don't send attachments to the list. Messages with attachments take up too much bandwidth. Event files should be sent to event@............. so that they get archived. Thanks. -Larry At 07:32 AM 9/11/97 -0700, you wrote: >Hi All > Well in the last 12 hours I got 48+ additional atypical local events. >I have included two of the typical ones. > Barry > >Attachment Converted: "C:\NET\NEW\970911K.BL" > >Attachment Converted: "C:\NET\NEW\970911M.BL" > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz <gbl@.......> Subject: Re: local events Date: Fri, 12 Sep 1997 06:38:25 -0700 Gary There are quarries in the foothills but I am not aware of any blasting. I agree that the source is probably not geologic. There were suspiciously no events recorded after dark. There has been some logging about 1 mile from my house. Maybe trees falling in the forest do make sounds. :-} Barry BTW - Where is your location? I asume near WSU. Gary Chantler wrote: > > >Hi All > > Well in the last 12 hours I got 48+ additional atypical local events. > >I have included two of the typical ones. > > Barry > > > > Do you have gravel pits in your area. They're blasting like crazy up here! > Looks pretty similar on the seismogram too. > GRC > > *********************************************************** > ***************************************** > Gary R. Chantler > Instructional Tech. II > Geology 101 > (509) 335-5353 Webster Rm 922 > gchantler@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz <gbl@.......> Subject: Re: local events Date: Fri, 12 Sep 1997 06:41:19 -0700 Ed I do record lightning spikes here but they are usually only one or two cycles in length. I do believe they are probably not geologic in origin. Barry Edward Cranswick wrote: > > Barry- > Have you've been having any thunderstorms near you. > -Edward > > barry lotz wrote: > > > > Hi All > > Well in the last 12 hours I got 48+ additional atypical local events. > > I have included two of the typical ones. > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick <cranswick@........> Subject: [Fwd: Re: TREMOR/SOS Prototype Site] Date: Tue, 16 Sep 1997 12:31:35 -0600 -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". From: Larry Cochrane <cochrane@..............> Subject: SG sensor testing and SG Electronics board Date: Tue, 16 Sep 1997 16:23:00 -0700 Hi There, Well I finally got around to doing something I have always wanted to do. That was to test the frequency response of the SG (Shackleford-Gundersen) seismometer. I wanted to check if the integrator, used to make the short period sensor look like a long period one, compensates correctly for the natural decrease in response to lower frequencies of a 10 inch pendulum. To do this test I needed to make a shake table. The heart of my shake table is a 25000 step per rev. stepping motor. By using a stepping motor I could control the speed by simple putting in a square wave signal at 25000 times the frequency I wanted. Another words, if I put in a 25000 hz signal into the stepping motor's control box I would get 1 rev per second. On the motor's shaft I super-glued a washer that was offset a little to act as a cam. The sensor was placed on two rods that acted as rollers. A lever was made to push against the cam on the motor end and the sensor on the other end. I used two springs, that where connected to the sensor and base of the shake table, to keep the lever against the cam and sensor. When the motor rotated it would move the sensor in a sine-wave motion. For this test I made a light framed SG sensor with a 10 inch pendulum. I was not interested in sensitivity, only frequency response, so I never actually measured the distance the sensor was moving. From eye balling it I would say I was moving the sensor 1 or 2 mm. Despite this small movement I needed to reduce the gain of the electronics by a factor of 20 so it would not saturate the electronics. After some playing around with the shake table and sensor aliment a little I was able to get a pretty good looking sine-wave out of it. The first freq. response run was with a 130 second (4.4 uf cap & 4.7 meg feedback resistor) integrator that I have been using with my two SG sensors I have online. The original SG sensor article, in the September 1975 Scientific American Magazine, used a 62 second integrator. I'm not sure why I was running mine at the longer time constant. It was quite obvious that the 130 second integration was way too much. So I started to deduce the integration until I got a freq. response curve that was relatively flat (+- 3 db) between 50 seconds and around .5 seconds. Above .5 seconds I ran into another problem that was related to the dampening of the pendulum, but more about that later. To get the flat response out of the sensor I had to reduce the integration down to 6.2 seconds (1 uf cap & 1 meg resistor). This is 1/10 the amount that the original SG article uses. I have now changed the integration for all of my SG sensors to the 6.2 second value. I am now waiting for a teleseismic event so I can test to see how this change effects the seismograms compared to my Lehman and the Berkeley broadband sensor I like to use for comparison. This table also allowed me to do another test I have always wanted to do. That was to test the freq. response of a sensor and change the dampening to see how it effects the response curve. As I said above, my SG testing showed an increase in sensitivity above .5 and peeking at the natural freq. of the pendulum. Before the testing I thought I had set the dampening to ..700. I was surprised to see so much increase in sensitivity. So, to get a flatter response curve I set the freq. of the shake table so it was moving at the period of the pendulum and then I started to add dampening until I reduced the sensitivity of the sensor to the point where I was getting the same amount of signal that I got below .5 hz. After making the dampening change I was able to get the sensor to have a flat (~3 db) response from ~50 seconds to ~3 hz! But to get the this flat response I really need to increase the dampening by quite a lot. All of this testing was done to finalize the design of a new board I am adding to my product line. This board implements all of the electronics needed to build an SG sensor. I have started a web page for the board at http://psn.quake.net/sgboard.html. There you will see a photo of the board and a short write up on what the boards does, cost etc. Regards, Larry Cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick <cranswick@........> Subject: Re: SG sensor testing and SG Electronics board Date: Tue, 16 Sep 1997 22:02:55 -0600 Larry- I was impressed by your thorough and readable description of your SG calibration procedure. However, it is not clear to me what is meant by a 6.2 s value for integration. Do you now know, in fact, what the value of your damping is? Also, what limits the flatness of your response above 3 Hz? It sounds as if you are aiming for some precise measurements of absolute ground motion. I am glad that you are concerned about calibration. -Edward -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Giovanni Rotta" <rottag@..........> Subject: Low seismic activity Date: Wed, 17 Sep 1997 07:10:37 +0200 HI all ! There is a very low seismic activity here in Europe. What is the situation in the other sites ? Greetings, Giovanni Giovanni Rotta rottag@.......... Via F. Pizzigoni, 10 33010 Resia (Udine) Italy Lat. 46.22N Long. 13.18E _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "James M Hannon"<jmhannon@........................> Subject: RE: SGSensor testing Date: Wed, 17 Sep 1997 08:20:24 -0500 Larry, I read with great interest you description of calibrating a SG sensor. I have a general question. The mechanical arrangment you described would produce a constant displacment of the instrument vs frequency. But the SG sensor is really an accelorometer. So did you make the acceleration output of the sensor flat with frequency or the equivalent displacment output? A general question -- What would be the best to record acceleration, velocity or displacment? Jim Hannon _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Karl Cunningham <karlc@.......> Subject: Re: SG sensor testing and SG elect Date: Wed, 17 Sep 1997 08:17:21 -0700 Larry -- Your shaker table work is great! I've dreamed of making one for a long time. This is a big step toward being able to use our data for analytical work. One observation: From your description, I assume the shaker table's movement is constant *displacement* regardless of frequency. This means your SG's frequency response is also flat with constant-displacement shaking. From my [somewhat meager] knowledge of seismology, the *velocity* of earth movement from earthquakes is sort-of flat as a function of frequency. Because displacement is the integral of velocity, the SG's output should be more sensitive to low-frequency velocity signals and therefore be more sensitive to teleseismic events and less sensitive to local events. As a related item, I have been using the *acceleration* output of my force-balance instrument for local events. I find it is *much* more sensitive than the velocity output -- but only for local events (<250km). So much so that an event producting a small bit of signal superimposed on the 6-second background noise of the velocity output produces a very clean signal (10:1 SNR or better) from the acceleration output. Karl Cunningham La Mesa, CA. PSN station #40 karlc@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: gchantler@....... (Gary Chantler) Subject: Re: local events Date: Wed, 17 Sep 1997 09:45:05 -0800 Hi all, (Barry) Sorry my reply was not more prompt. My wife and I were having a baby. Girl (Heather) 8.75 lbs. I have some/many blasts and should probably send some to you for comparison. Tree falling could be and explaination as well. The blasting around here (WSU - Physical Science Bld.) takes place at least 2 miles from the machine - but doesn't produce anywhere near the amplitude of your trace...???HMMM. GRC *********************************************************** ***************************************** Gary R. Chantler Instructional Tech. II Geology 101 (509) 335-5353 Webster Rm 922 gchantler@....... *#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#* _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane <cochrane@..............> Subject: Re: SG sensor testing and SG Electronics board Date: Wed, 17 Sep 1997 13:28:57 -0700 Hi Edward and PSN'ers, At 10:02 PM 9/16/97 -0600, you wrote: >Larry- > I was impressed by your thorough and readable description of your SG >calibration procedure. However, it is not clear to me what is meant by >a 6.2 s value for integration. The integrator is an op-amp setup as an inverting amplifier with a cap in the feedback loop of the op-amp. The cap is placed in parallel (you can see the schematic of the board at http://psn.quake.net/sg-schm.gif) with the feedback resistor. This RC combination sets up the corner freq. of the integrator. This can be calculated using the following formula: fc = 1 / ( pi * R * C). >Do you now know, in fact, what the value >of your damping is? No, but it needs to be very stiff to get the flat response. I'm wondering if I'm also dampening out the overall structure of the sensor, and, that's why it needs to be so stiff? >Also, what limits the flatness of your response >above 3 Hz? The integrator. It keeps cutting into the higher frequencies above the period of the pendulum. >It sounds as if you are aiming for some precise >measurements of absolute ground motion. That's the next thing to do... I want to get an overall sensitivity of the device, but I first needed/wanted to get a flat response out of the thing so I wouldn't have to worry about specifying a frequency for the sensitivity. Another words if it has a flat response, say from 50 sec. to 3 hz., then when I do the sensitivity testing I won't have to worry about specifying at what freq., as long as the testing was done somewhere in the 50 sec. 3 hz. range. It would seem to me that if the sensors did not have a flat response then specifying the sensitivity becomes more complex. One would have to say that the sensor has a sensitivity of X at one freq. and another sensitivity at a different freq. If I'm missing something here PLEASE let me know... My question to others who may know more about these things and has worked with broadband sensors like the Streckeisen STS-1 Seismometer is; If I where to do the same freq. response test with this type of sensors would I get a flat response out of it??? Regards, Larry Cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jean-Jacques HUNSINGER <jjh@............> Subject: Re: Low seismic activity Date: Wed, 17 Sep 1997 23:42:54 +0200 Hi Giovanni it's the same status here in France... Giovanni Rotta wrote: > > HI all ! > There is a very low seismic activity here in Europe. > What is the situation in the other sites ? > Greetings, > > Giovanni > > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick <cranswick@........> Subject: Re: [Fwd: Re: TREMOR/SOS Prototype Site] Date: Wed, 17 Sep 1997 20:25:12 -0600 Barry- Thank you very much for your response to the TREMOR message I forwarded to the PSN-L from John Evans, USGS Menlo Park. However, as I have said before, John is the one in charge of the project and is the one calling the shots on where the stations are to be deployed, and I am just acting as a connection between the PSN and the USGS. Therefore, you should direct any specific questions about TREMOR site possibilities to John Evans <evans@....................>, though I would like the PSN-L to be CC'd just to keep in touch with what is going on with respect to this important development of potential direct USGS/public cooperation. So where is this particular "goo valley"? Many, if not most, valleys can be described in terms of that rheology. -Edward barry lotz wrote: > > Edward > If you are interested on a station across the valley "goo canyon" > let me know. > Barry > Edward Cranswick wrote: > > In the best of all worlds, we hope for sites every 1 km, or even every few hundred meters. (Shaking varies a LOT over re markably short distances, and we need to be able to direct Emergency Services to individual small neighborhoods with urgent nee ds. -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: watson@................ (Charles Watson) Subject: [Fwd: Re: seismic monitoring networks] Date: Thu, 18 Sep 1997 14:49:18 -0700 This conversation is currently circulating on the Western States Seismic Policy Council listserve. Perhaps you may want to comment? -- ---/---- Charles P. Watson, Consulting Geologist Advanced Geologic Exploration Seismo-Watch / Earthquake Information Services Voice: 702-852-0992 / Fax: 702-852-3226 Office Location: 39.43N 119.71W mailto:watson@................ http://www.seismo-watch.com WSSPC Discussion Group: As Mike mentioned the USGS has been deploying a state of the art network of broadband stations during the last several years. I too would like to see full implementation of the network at the planned level. However, I am uncertain that these resources have been deployed in a cost effective manner, or that the sites selected for the USNSN stations to date are the best available. When one looks at the existing USNSN stations shown on a map versus actual downloadable earthquake data--the percentage of stations recording data is among the lowest of any network with which I am familar. In addition, a satellite failure shut down the network during early '97 and late '96. Some sites appear to have never collected data (e.g. Yellowstone). This is especially dissapointing when considering a single USNSN station costs more than some entire networks. Unfortunately the pattern seems to be continuing. A planned site in northern Arizona near active mines, on young volcanics and outside an internet connection should help leave the USNSN track record intact. Before WSSPC pushes for full implementation, we should first review the cost-benefit of the USNSN and its role in reducing earthquake hazards in the U.S. Doug Bausch Arizona Earthquake Information Center On Sun, 14 Sep 1997, Mike Stickney wrote: > Dear WSSPC discussion group: > As the operator of a small regional seismic network in the Northern > Rocky Mountains, I would like to confirm that there is a dearth of modern > instrumentation in this region. The US National Seismograph Network > (USNSN), operated by the USGS, has never been completed as planned in the > western US. Apparently, the first five years of funding for the USNSN > program came from the Nuclear Regulatory Commission and was used to design > and develop standard instruments and deploy them in the eastern US, where > most nuclear power plants are located. The program to operate the network > and deploy instruments in the western US was handed to the USGS without the > benefit of additional funding from Congress. (I hope somebody with more > knowledge on this history will set the record straight if I have mis-stated > the facts here). A number of educational institutions with strong > seismology programs have established cooperative stations with the USNSN, > but other parts of the western US remain pooly covered by the existing > network. The Northern Rocky Mountain region remains the most seismically > active region in the lower 48 states outside California and Nevada but there > are no broadband seismographs located here. > > I would like to see WSSPC push for full implementation of the USNSN > at the originally planned level. > > Mike Stickney > Montana Bureau of Mines and Geology > Montana Tech of the University of Montana > Butte MT 59701 > > voice 406 496-4332 > fax 406 496-4451 > email mike@................. > =========================================== > At 02:38 PM 9/9/97 -0700, Steven Ganz wrote: > >We would like to hear your comments on the following motion adopted by the > >WSSPC Board of Directors. The WSSPC membership will vote on this policy > >recommendation at the WSSPC Annual Conference in November. > >******************** > > > >WSSPC PR97-4: Seismic Monitoring Networks > > > >Because seismic monitoring networks are vital for earthquake hazard > >characterization and because there is an insufficiency in available data, > >WSSPC encourages the continuation and expansion of seismic monitoring > >networks, including strong motion instruments. > >********************* > > From: Larry Cochrane <cochrane@..............> Subject: RE: SG Sensor testing Date: Thu, 18 Sep 1997 15:22:50 -0700 At 08:20 AM 9/17/97 -0500, Jim Hannon wrote: >Larry, >I read with great interest you description of calibrating a SG sensor. I >have a general question. The mechanical arrangment you described would >produce a constant displacment of the instrument vs frequency. But the SG >sensor is really an accelorometer. I don't think so... The sensor has active dampening, that may make it look like an accelerometer, but the dampening loop is AC coupled and I think an accelerometer has a DC loop. I think the sensor would behave the same if the dampening was oil or magnetic (copper plate in a strong magnetic field) like we use for our Lehman's. > So did you make the acceleration output >of the sensor flat with frequency or the equivalent displacment output? I think the output is velocity. The low freq. port signal goes though several stages. The signal starts as displacement because of the receiving antennas and the summing amp. The output of the summing amp is DC and is proportional to the placement (displacement?) of the pendulum. The output of the summing amp feeds the dampening circuit and also feeds a 60 sec. high-pass filter. After the high-pass filter the signal becomes a velocity signal. The low freq. port signal then goes into the integrator that converts it back to displacement. The output of the integrator then goes into another 60 sec. high-pass filter that converts it back to velocity. The output of the second high-pass filter then goes info a 5-hz low-pass filter and then out to the A/D card. The high freq. port bypasses the integrator and is also a velocity signal because it goes though a high-pass filter and then into a low-pass filter and then out to the A/D card. As usual, if I have missed something here please correct me. I'm not a electromechanical engineer so I'm a little out of my field when dealing with this type of stuff. -Larry Cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Greg Lyzenga <lyzenga@.................> Subject: RE: SG Sensor testing Date: Thu, 18 Sep 1997 16:53:12 -0700 >> So did you make the acceleration output >>of the sensor flat with frequency or the equivalent displacment output? > >I think the output is velocity. The low freq. port signal goes though >several stages. The signal starts as displacement because of the receiving >antennas and the summing amp. The output of the summing amp is DC and is > > ... stuff omitted > >As usual, if I have missed something here please correct me. I'm not a >electromechanical engineer so I'm a little out of my field when dealing >with this type of stuff. > >-Larry Cochrane >Redwood City, PSN > I think the question was (if I understood it correctly!), what was it that was held constant in your shake table tests as you swept through frequencies? Was it the amplitude of the shake displacement, or the amplitude of the velocity (or something else)? And when you say that the output is "flat" over some frequency range, does that mean flat with respect to these shake tests, or have you applied some other conversions before interpreting the results? Sorry if I've misunderstood either the original question, or Larry's answer to it... - Greg Gregory A. Lyzenga, Dept. of Physics, Harvey Mudd College -> lyzenga@................. <- _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane <cochrane@..............> Subject: RE: SG Sensor testing Date: Thu, 18 Sep 1997 17:00:27 -0700 At 04:53 PM 9/18/97 -0700, Greg wrote: >I think the question was (if I understood it correctly!), what was it that >was held constant in your shake table tests as you swept through >frequencies? Was it the amplitude of the shake displacement, or the >amplitude of the velocity (or something else)? The table, do to the way it is mechanically setup, would give an equal displacement amplitude, independent of frequency. I'm not sure how I would construct it any other way??? >And when you say that the >output is "flat" over some frequency range, does that mean flat with >respect to these shake tests, or have you applied some other conversions >before interpreting the results? No conversions, I used the peek to peek output voltage of the low freq. output port. What I did was use a period of 10 seconds as a center point and adjusted the overall gain of the system so that I got a ~1.3 peek to peek output voltage. I then adjust the integrator, at the low end, and the dampening, at the high end, so I got approximately the same output voltage between 50 sec. and 3 hz. To make my measurements I used an oscilloscope and SDR. -Larry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane <cochrane@..............> Subject: Re: response Date: Thu, 18 Sep 1997 18:07:34 -0700 I'm forwarding this from John Lahr, At 05:18 PM 9/18/97 -0800, Dr. John C. Lahr wrote: >Hi Larry, > >I can't write to the PSN, so I'll just send this to you. > >Then, to finish beating a dead horse, the calibration amplitude >you measured on your computer's screen in counts with SDR, when all >is said and done, is constant over the range 3 Hz to 50 s. > >If so, it is "flat to amplitude" over this range. > >JCLahr That's what I thought... Now for the 64K $ question. Given that WinQuake can calculate ML and Ms (and someday Mb) magnitudes isn't that what we want? I'm not sure why John, and apparently others, are having problems posting to the list. Since John can send email to cochrane@.............. I an testing sending email to the list using PSN-L@............... Since the domains psn.quake.net and webtronics.com come to the same system, both addresses (PSN-L@.............. and PSN-L@.............. should work. John, can you send a test message (or answer the 64K $ question <G>) too the PSN-L@.............. address? -Larry Cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: lahr@................. (Dr. John Lahr (USGS-GI Seismologist)) Subject: A test to PSN-L@.............. Date: Thu, 18 Sep 1997 18:44:17 -0800 Just a test. The issue is how to optomize the dynamic range of the recording system, given the spectrum of the signal that you expect to record. As the dynamic range increases, the shape of the response becomes less of an issue. I'll leave the rest of the answer to Ed! JCLahr _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz <gbl@.......> Subject: Re: SG sensor testing and SG Electronics board Date: Thu, 18 Sep 1997 08:39:46 -0700 Hi Larry Your testing was very interesting.Where did you find a stepper motor with that many positions? A while back I experimented with a shaking table design. I used two horizontal parallel plates separated by flexible spring steel strips (restraining the movement to mostly one direction). The lower plate was fixed to the ground and the upper plate was the base for the sensor. The upper plate was excited by two peizoelectric disks attached to the upper plate and vertical extension of the lower plate. A sine wave voltage was applied to the peizo disk and the sensor response was noted. I had plans to put a LVDT at the peizo or the table to measure the small displacements of the the table but haven't got that far. The few merits I see to this design is one can measure sensor response at actual gains, change magnitude and frequency at desired intervals, and have basicly no moving mechanical parts that may induce vibrations. The LVDT would provide the calibration link to reality. Barry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Giovanni Rotta" <rottag@..........> Subject: Event in Europe Date: Fri, 19 Sep 1997 15:36:34 +0200 Hi all ! At last, a nice event here in Europe: 12:01 UTC ml 5.0, probably located on the Greece - Albania border. Did someone chek it ? Regards, Giovanni Giovanni Rotta rottag@.......... Via F. Pizzigoni, 10 33010 Resia (Udine) Italy Lat. 46.22N Long. 13.18E _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson <dann@........> Subject: Re: Event in Europe Date: Sat, 20 Sep 1997 13:06:38 +1200 gidday Giovanni, here is the USGS data 97/09/19 12:00:28 40.06N 21.04E 10.0 4.8Mb GREECE Dave At 03:36 PM 9/19/97 +0200, you wrote: >Hi all ! >At last, a nice event here in Europe: 12:01 UTC ml 5.0, probably located on >the Greece - Albania border. >Did someone chek it ? >Regards, >Giovanni > >Giovanni Rotta >rottag@.......... >Via F. Pizzigoni, 10 >33010 Resia (Udine) Italy >Lat. 46.22N Long. 13.18E > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > Co-ordinator: New Zealand Public Seismic Network Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane <cochrane@..............> Subject: More on SG sensor testing. Date: Sun, 21 Sep 1997 17:19:31 -0700 Greetings, The 6.9Ms Kermadec Is. event yesterday allowed me to see how the changes I made to the SG electronics effected the signal out of the sensor. In a word the results are "mixed". The seismogram from my SG sensor still look similar to the Berkeley broadband sensor I am using as a reference. But there seems to be more high frequence info in the seismogram that is not in the broadband seismogram. What's interesting is the seismogram that is produced when you take the SG sensor and integrate the data. After doing the integration the seismogram almost looks identical to the Berkeley broadband sensor. The following files can be downloaded: ftp://psn.quake.net/quakes/9709/970920a.bkn This is a PSN format event file from the Berkeley broadband N-S sensor. I created it by downloading a SAC binary event file I made using a program on the Berkeley system. This program allows you to extract data from there continuous recorded data for the broadband sensor they are monitoring. It's similar to doing a replay in SDR. I then used WinQuake to convert it to PSN format. Since the SAC binary data is in 24 bit format I had to divide the data by 10 so that it would fit into the +- 32K (16bits) short data array used in the PSN event files. I also have the raw SAC binary files in my /incoming dilatory at ftp://psn.quake.net. ftp://psn.quake.net/quakes/9709/970920a.lc1 This event file is from my N-S Lehman. ftp://psn.quake.net/quakes/9709/970920a.lc3 This event file is from my SG sensor under test. For those of you who can't run WinQuake I have made the following screen shots of the event window and converted them to gif format. Each is around 40k in length. http://psn.quake.net/info/bkntest.gif The Berkeley sensor. http://psn.quake.net/info/lc1test.gif My Lehman sensor. http://psn.quake.net/info/lc3test.gif My SG sensor. http://psn.quake.net/info/lc3itest.gif My SG sensor, integrated view. One interesting point is the overall sensitivity of the SG sensor when compared to the broadband sensor. The surface waves produced a +- max count of around 26700 counts (or +-2670 counts on the PSN format BKN file do to the divide by 10). The SG sensor produced a ~ +- 4860 min/max count. This means, I think, that the broadband sensor is about 5.5 times more sensitive to the ~17 second period surface wave used to for the min/max counts. The problem with this 5.5 X number is what effect does the different location of the two sensors have on the sensitivity? Does anyone have a feeling on how much amplification or attenuation the local ground can have on the low frequency surface waves? It would be great if I could place a SG sensor next to a broadband sensor somewhere. This would remove one variable... -Larry Cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: DSeeber101@....... Subject: hypocenters Date: Mon, 22 Sep 1997 18:23:16 -0400 (EDT) From: Don Sieber 97-09-22 16:14 mdt dseeber101@....... I have a question about making a determination of the depth of the hypocenter. Is there a simple way it can be done with only one receiving station? I understand that a pP wave can be used, (The one traveling from the hypocenter to surface) but I don't believe I've ever identified one. Thanks. Don _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane <cochrane@..............> Subject: Files sent to event@............. and the NewEvent mailing Date: Tue, 23 Sep 1997 01:31:07 -0700 Stephen, It looks like you shouldn't be a member of the NewEvent mailing list. When PSN stations want to upload event files for archiving on my system they send then, as attachments, to the event@............. address. The same email message, along with the attachment, is forwarded to the NewEvent@......... mailing list so others can receive the event files directly. Frank's file was a bit larger then normal, and, I have asked him to cut down on the file size by reducing the sample rate. But on an active day you can expect a lot of event files will over the 650k. As far as unsolicited files... didn't you subscribe to the NewEvent list? If not I will remove you. -Larry Cochrane Redwood City, PSN At 01:01 AM 9/23/97 -0700, Stephen Paul wrote: > >Welcome to the club! However I'm sure I speak for many of us here when I ask that you and others -=refrain=- from uploading >!645KB! unsolicited files into our mailboxes. Please in the future respect the fact that an attachment which may seem >important to you is hardly worth that kind of d/l time clogging our pop servers. > >In fact may I submit to the entire group that the sending of attachments either be limited to 10-15K at *most* or, better yet, >done through request of the individual(s) wanting to bother decoding and receiving them, and therefore clogging only his/her >mailboxes, thereby encouraging the original exchange of -ideas- which attracted me to this list in the first place, rather >than the current mania for attaching large octets. > >Thank you all, >-- >Stephen :^) > > >FCooper242@....... wrote: > >> Hi, >> The Kermadec is included in the attachment. I'm about a second off on the >> timing. This is my first effort in sharing with PSN. >> Thanks, >> Frank Cooper, Friendswood, Texas >> >> ------------------------------------------------------------------------ >> >> Name: 970920I.FC1 >> 970920I.FC1 Type: unspecified type (application/octet-stream) >> Encoding: base64 > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson <dann@........> Subject: Re: Files sent to event@............. and the NewEvent mailing Date: Tue, 23 Sep 1997 23:13:17 +1200 Larry, I have been working with Frank over the last couple of days about the operations of winquake and also on the file size I had also said to him about cutting down the sample rate to 12.5 or 25 sps Stephen was definately a bit harsh.... as it was Franks first posting and everyone is allowed a few mistakes until they learn to get a handle on SDR and Winquake. as I said to Frank in private mail Keep up the good work experiment with the sample rate, and the different WQ tools and we hope to see more postings Dave N. At 01:31 AM 9/23/97 -0700, you wrote: >Stephen, > >It looks like you shouldn't be a member of the NewEvent mailing list. When >PSN stations want to upload event files for archiving on my system they >send then, as attachments, to the event@............. address. The same >email message, along with the attachment, is forwarded to the >NewEvent@......... mailing list so others can receive the event files >directly. > >Frank's file was a bit larger then normal, and, I have asked him to cut >down on the file size by reducing the sample rate. But on an active day you >can expect a lot of event files will over the 650k. > >As far as unsolicited files... didn't you subscribe to the NewEvent list? >If not I will remove you. > >-Larry Cochrane >Redwood City, PSN > Co-ordinator: New Zealand Public Seismic Network Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson <dann@........> Subject: better loc's for Calif. stns Date: Tue, 23 Sep 1997 23:37:36 +1200 Hi ya all, I am going to bug all you Calif. guys again, I am after better locations for you all WHY!!!! you ask Well Erich Kern in Murrieta, 50 odd miles nth of San Deigo, kindly, and out of the blue, sent me by snail mail some very good maps of Calif. which include closeups of the main cities... ( if felt quite weird seeing all the street names (particurlarly in LA) that I feel I know so well after hearing them so often in films, TV progs., and news clips, almost felt like I had been there (well maybe when I win Lotto) I'm picking the best way is to correspond with each individual personally (e-mail) giving a few a few major road/street names from the maps, in your area, to see if we can narrow you down. I hope you don't mind indulging my sideline interest will be in touch with you all soon Dave Co-ordinator: New Zealand Public Seismic Network Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: GeE777@....... Subject: Using Geophone sensors Date: Tue, 23 Sep 1997 15:17:47 -0400 (EDT) Hello, I am new so bear with me. There is a lot I need to learn. Here is my background and interests. After many years, I have retired from working in the business of explorat= ion geophysics. ( I still do consulting ) My specific field is seismic acquisition for oil and gas exploration. We used geophones for sensors a= nd I have a few that I got as surplus since my seismic lab in the research division of an oil company was shut down when I retired. As you may know= , the seismic explorationist makes their own seismic signal with either explosives or mechanical devices. Geophones are not very sensitive to lo= w frequency seismic signals thus are not well suited for recording very low natural seismic signals. However, several times, I have seen seismic sig= nals from natural events on the multi-channel seismic systems used in seismic exploration. Some of these events were several hundreds of miles away. =20 I have a three component geophone in a shallow hole beside my house. Rig= ht now, I am recording only the vertical component by using an amplifier and anti-aliasing filter into an A/D converter attached to a PC. I have reco= rded several local events here in Southern California in the last few weeks. = I record only events that are strong enough to trigger the recorder. My sa= mple rate is 8 MS and I record for 120 Seconds. ( Maximum samples the softwar= e permits ) My goal is to improve recording seismic events and use all three componen= ts of the geophone. E/W, N/S, and V. I would like to record data prior to = the triggering level. ( I used to do this in the seismic lab using a digital oscilloscope ) I need to record time, such as a WWV signal. And, of cou= rse, one is always fighting for better signal to noise ratio. =20 I would like to know if any of you would be interested in the results of = my efforts. I would like feedback from those interested. You may E-Mail me directly so we don=92t clog up the system. In a recent e-mail, Larry Cochrane explained how he tried to determine th= e sensitivity of a seismometer system. I don=92t know if this will help hi= m but I have found a way to determine the sensitivity and frequenxy response of= the recording system that uses a geophone sensor by recording the system step function response. George Erich GeE777@....... Phone (562) 868-6013 Norwalk, CA=20 _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Steve Hammond <shammond@...........> Subject: Re: better loc's for Calif. stns Date: Tue, 23 Sep 1997 13:48:55 -0700 David A Nelson wrote: > Hi ya all, > I am going to bug all you Calif. guys again, I am > after > better locations for you all > Dave, I think I have a helpful way to do this. Let me introduce you to http://www.mapquest.com/ which is a detailed map service in the USA and soon worldwide. Go to the web site and click on "Find a Place" and lets get you within a few block of my house as a test. (For security reasons I'll not post the numbers.) For the street enter- Calpine & Herlong Town- San Jose State- CA.If this works as well for you as it did for me, you should see I am in the south end of San Jose between Lean and Cottle near the 85 Freeway. BTW, the light rail commuter trail I talk about from time to time runs along the 85 Freeway. My thought is that people could help you locate their site by providing the Street & Cross_street, Town, State inputs after checking the data out. Regards, Steve Hammond PS: at some point, Mapquest will have the data for worldwide searches. Checkout the NZ maps that are already there. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson <dann@........> Subject: Re: Using Geophone sensors Date: Wed, 24 Sep 1997 11:27:05 +1200 Hi there George , welcome to the group, I have been using 4.5Hz geophones here in New Zealand for some 10 years on a standard drum recorder they work very well for regional events and large events up to 2-3000km this morning I posted to the new events file on Larry C's system a double event that was around 1150 km away foreshock~M5.7 and Main shk ~M6.2 Last December I fired up one of Larry's A to D boards and software see his home pages http://psn.quake.net it has multi channel, wwv timing ability, various sample rates, and many other good features. there are a large number of us around the world using this system so file swapping of recorded events amongst ourselves is no problem. The system runs 24hrs a day seven days a week using ~4.9Mb of HDD space per channel per day when using the 12 bit adc chip in a few words DON'T hesitate buy one now you won't regret it........ Chow Dave At 03:17 PM 9/23/97 -0400, you wrote: >Hello, > >I am new so bear with me. There is a lot I need to learn. Here is my >background and interests. > >After many years, I have retired from working in the business of exploration >geophysics. ( I still do consulting ) My specific field is seismic >acquisition for oil and gas exploration. We used geophones for sensors and I >have a few that I got as surplus since my seismic lab in the research >division of an oil company was shut down when I retired. As you may know, >the seismic explorationist makes their own seismic signal with either >explosives or mechanical devices. Geophones are not very sensitive to low >frequency seismic signals thus are not well suited for recording very low >natural seismic signals. However, several times, I have seen seismic signals >from natural events on the multi-channel seismic systems used in seismic >exploration. Some of these events were several hundreds of miles away. > >I have a three component geophone in a shallow hole beside my house. Right >now, I am recording only the vertical component by using an amplifier and >anti-aliasing filter into an A/D converter attached to a PC. I have recorded >several local events here in Southern California in the last few weeks. I >record only events that are strong enough to trigger the recorder. My sample >rate is 8 MS and I record for 120 Seconds. ( Maximum samples the software >permits ) > >My goal is to improve recording seismic events and use all three components >of the geophone. E/W, N/S, and V. I would like to record data prior to the >triggering level. ( I used to do this in the seismic lab using a digital >oscilloscope ) I need to record time, such as a WWV signal. And, of course, >one is always fighting for better signal to noise ratio. > >I would like to know if any of you would be interested in the results of my >efforts. I would like feedback from those interested. You may E-Mail me >directly so we don't clog up the system. > >In a recent e-mail, Larry Cochrane explained how he tried to determine the >sensitivity of a seismometer system. I don't know if this will help him but >I have found a way to determine the sensitivity and frequenxy response of the >recording system that uses a geophone sensor by recording the system step >function response. > >George Erich >GeE777@....... > >Phone (562) 868-6013 >Norwalk, CA Co-ordinator: New Zealand Public Seismic Network Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson <dann@........> Subject: Re: better loc's for Calif. stns Date: Wed, 24 Sep 1997 12:18:29 +1200 Steve, that is excellent, maybe a lot of the other group members don't know about that site either. many thanks. If the others want to send me street addresses plus the two closest major intersecting roads (in private e-mail) this could be a lot of fun..... thank heavens I have unlimited web access for a fixed price, so as to spend the time searching TNX again Steve Dave >Dave, I think I have a helpful way to do this. Let me introduce you to >http://www.mapquest.com/ which is a detailed map service in the USA >and soon worldwide. Go to the web site and click on "Find a Place" and >lets get you within a few block of my house as a test. (For security >reasons I'll not post the numbers.) For the street enter- Calpine & >Herlong Town- San Jose State- CA.If this works as well for you >as it did for me, you should see I am in the south end of San Jose >between Lean and Cottle near the 85 Freeway. BTW, the light rail >commuter trail I talk about from time to time runs along the 85 >Freeway. My thought is that people could help you locate their site by >providing the Street & Cross_street, Town, State inputs after checking >the data out. >Regards, Steve Hammond > >PS: at some point, Mapquest will have the data for worldwide searches. >Checkout the NZ maps that are already there. Co-ordinator: New Zealand Public Seismic Network Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz <gbl@.......> Subject: microseisms Date: Tue, 23 Sep 1997 09:33:49 -0700 Hi All Has anyone seen a marked increase in ~ 0.13 hz microseisms within the last day or so? I suspect it is storm/ocean related. Though the weather is like summer I have had to reduce my gain by 2. Barry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Karl Cunningham <karlc@.......> Subject: Re: microseisms Date: Tue, 23 Sep 1997 23:46:45 -0700 Barry -- Background noise has been up for the last four days for me. My threshold is 3x the normal setting right now, and I'll have to reduce it even further soon. Hurricane Nora, I think. Karl Cunningham La Mesa, CA. PSN Station #40 karlc@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert L Barns <75612.2635@..............> Subject: More on SG sensor testing. Date: Wed, 24 Sep 1997 09:10:17 -0400 Larry, I'm reading the e-mail which accumulated during a vacation in Los Alam= os where my daughter is doing a post-doc in microbiology at the labs. (If y= ou want to read some weird stuff, try her web page = www-ls.lanl.gov/~sbarns/crenarchaeota.html The www-ls is correct but was= something new to me.) Had a fine time-rode the narrow-gage train from Durango to Silverton (CO) again, a trip I can recommend. I found your shake table work and the subsequent messages very interesting. The use of a stepping motor was a slick idea. A few commen= ts about your comparison of the SG and Berkeley broadband seismograms:You compare them on the basis of peak-to-peak counts. I suggest that the comparison would be more meaningful if it was in terms of actual velocities, e. g., nanometers/sec. This is what I did in my write-up on the meter-movement calibrator for the Lehman. Your question about sensitivity differences due to local ground conditions is certainly important. There is a good discussion of this factor in Bolt "Earthquakes and Geological Discovery" esp. pp 164-179 and= chapter 9. That discussion is mostly about surface waves so it should apply to the teleseismic recordings. I want to build another sensor and the coming availability of your electronics package for the SG may make my choice of what to build much easier. Bob Barns _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Dennis Leatart <ASTROSEEK@.........> Subject: Re: microseisms Date: Wed, 24 Sep 1997 06:28:41 -0700 Hi Barry! There hasdefinitely been an increase in microseisms on my seismo here in Moorpark California over the last day or so-- Hurricane Nora??? -- _____ __ | \.-----.-----.-----.|__|.-----. | -- | -__| | || ||__ --| |_____/|_____|__|__|__|__||__||_____| _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Greg Lyzenga <lyzenga@.................> Subject: Re: microseisms Date: Wed, 24 Sep 1997 08:54:29 -0700 >Hi All > Has anyone seen a marked increase in ~ 0.13 hz microseisms within the >last day or so? I suspect it is storm/ocean related. Though the weather >is like summer I have had to reduce my gain by 2. > Barry Yes! The tropical storm activity off Baja Californis this past month has correlated perfectly with my recording of "6-second" microseisms. They are stronger than ever this morning. Check out http://photon.physics.hmc.edu/research/geo/last_hour6.gif for an example! - Greg Gregory A. Lyzenga, Dept. of Physics, Harvey Mudd College -> lyzenga@................. <- _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: dean sevold <dsevold@..............> Subject: Event S.Vancouver Island Date: Wed, 24 Sep 97 09:25:37 PDT There was a tremor last night felt in the Brentwood Bay area, about 10:05= pm pst. Anyone else feel it, or record? Dean Sevold _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick <cranswick@........> Subject: HAM interested in earthquake prediction Date: Wed, 24 Sep 1997 13:16:16 -0600 Dorothy- I am turning this email over to Lary who can type with all fingers. Hope you are well. Best regards to you and Jerry. -Edward hello, I have been detecting earthquakes for fifteen years by hearing rumbles in my head !!!. These rumbles have correlated perfectly with a major earthquake seven days later. While traveling out west, I've stopped in and finally found this wonderful person named Ed. I am also an EXTRA class ham operator and would like to find a way to correlate all this information into some sort of network. Personally I am not on line yet and live on my sailboat ( which happens to be in port in San Diego at present). I will contact you again via some boat friends who are at the dock and have a land connection with the internet. I will be sailing across the Pacific in about one to two years and would be happy to do research and contribute if it is possible from a large sailboat. My "local" mail drop is : Lary Wasserman, 757 Emory Street (#129), Imperial Beach, California 91932. I'll also be up on 20 meters HAM band once I get back to the sailboat. For PSN: There are over 100 people in the HUMAN prediction group who have known physiologic effects before an earthquake. I'd like to find some way in which we can tie all this together to predict earthquakes. -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick <cranswick@........> Subject: Re: HAM interested in earthquake prediction Date: Wed, 24 Sep 1997 16:10:41 -0600 PSN- I did not mean to encourage earthquake predictors by connecting Lary Wasserman to the PSN, but rather to show Lary how he could connect to the various websites (he does not have internet access at present) that contained earthquake catalogs which he himself could use to make his own evaluations of his observations about earthquakes. I wanted him to be able to determine whether there was any correlation between his observations and the global record of earthquake occurrence. -Edward Edward Cranswick wrote: > > Dorothy- > I am turning this email over to Lary who can type with all fingers. > Hope you are well. Best regards to you and Jerry. > -Edward > > hello, I have been detecting earthquakes for fifteen years by hearing > rumbles in my head !!!. These rumbles have correlated perfectly with a > major earthquake seven days later. While traveling out west, I've > stopped in and finally found this wonderful person named Ed. I am also > an EXTRA class ham operator and would like to find a way to correlate > all this information into some sort of network. Personally I am not on > line yet and live on my sailboat ( which happens to be in port in San > Diego at present). I will contact you again via some boat friends who > are at the dock and have a land connection with the internet. I will be > sailing across the Pacific in about one to two years and would be happy > to do research and contribute if it is possible from a large sailboat. > > My "local" mail drop is : Lary Wasserman, 757 Emory Street (#129), > Imperial Beach, California 91932. I'll also be up on 20 meters HAM > band once I get back to the sailboat. > > For PSN: There are over 100 people in the HUMAN prediction group who > have known physiologic effects before an earthquake. I'd like to find > some way in which we can tie all this together to predict earthquakes. > -- > Edward Cranswick Tel: 303-273-8609 > US Geological Survey, MS 966 Fax: 303-273-8600 > PO Box 25046, Federal Center cranswick@........ > Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Rev. Bob Shannon" <rshannon@.......> Subject: Re: HAM interested in earthquake prediction Date: Wed, 24 Sep 1997 15:25:15 -0700 (PDT) Because I deal so much with alternate ways of prediction, I sent the information you gave on the list to a few others who are also interested in prediction methods -- some science -- some not... A person can combine the love of geology, earthquakes and ultr-theory into one..It is fun for sure! Bob http://iea.com/~rshannon/new.html Rev. Robert Shannon Sr. Hon. DD Theology Pinpoint Newsletter "The web existed before spiders. The web existed before the net... We are all a part of the web and whatever we do to part - we do to the whole" ------------------------------------------------------------------ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson <dann@........> Subject: Re: Event S.Vancouver Island Date: Thu, 25 Sep 1997 12:21:51 +1200 Dean, Yep there sure was USGS/NEIC 97/09/24 06:10:21 48.61N 123.02W 15.0 3.5Md VANCOUVER ISLAND REGION DAve N. At 09:25 AM 9/24/97 PDT, you wrote: >There was a tremor last night felt in the Brentwood Bay area, about 10:05 pm pst. Anyone else feel it, or record? > >Dean Sevold Co-ordinator: New Zealand Public Seismic Network Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Lucas Haag <lhaag@..............> Subject: Re: Using Geophone sensors Date: Wed, 24 Sep 97 21:31:21 CDT WELCOME GEORGE!! I am curious about your setup. Many others of the group have sent me circuts for an amp and I am curious about what you are using. Thanks & Welcome Lucas At 03:17 PM 9/23/97 -0400, you wrote: >Hello, > >I am new so bear with me. There is a lot I need to learn. Here is my >background and interests. > >After many years, I have retired from working in the business of exploration >geophysics. ( I still do consulting ) My specific field is seismic >acquisition for oil and gas exploration. We used geophones for sensors and I >have a few that I got as surplus since my seismic lab in the research >division of an oil company was shut down when I retired. As you may know, >the seismic explorationist makes their own seismic signal with either >explosives or mechanical devices. Geophones are not very sensitive to low >frequency seismic signals thus are not well suited for recording very low >natural seismic signals. However, several times, I have seen seismic signals >from natural events on the multi-channel seismic systems used in seismic >exploration. Some of these events were several hundreds of miles away. > >I have a three component geophone in a shallow hole beside my house. Right >now, I am recording only the vertical component by using an amplifier and >anti-aliasing filter into an A/D converter attached to a PC. I have recorded >several local events here in Southern California in the last few weeks. I >record only events that are strong enough to trigger the recorder. My sample >rate is 8 MS and I record for 120 Seconds. ( Maximum samples the software >permits ) > >My goal is to improve recording seismic events and use all three components >of the geophone. E/W, N/S, and V. I would like to record data prior to the >triggering level. ( I used to do this in the seismic lab using a digital >oscilloscope ) I need to record time, such as a WWV signal. And, of course, >one is always fighting for better signal to noise ratio. > >I would like to know if any of you would be interested in the results of my >efforts. I would like feedback from those interested. You may E-Mail me >directly so we don't clog up the system. > >In a recent e-mail, Larry Cochrane explained how he tried to determine the >sensitivity of a seismometer system. I don't know if this will help him but >I have found a way to determine the sensitivity and frequenxy response of the >recording system that uses a geophone sensor by recording the system step >function response. > >George Erich >GeE777@....... > >Phone (562) 868-6013 >Norwalk, CA > > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > ************************************************ Lucas Haag HCR 66 Box 25A Bartley, Nebraska 69020-9717 Email: lhaag@.............. World Wide Web: http://www.swnebr.net/~lhaag KC0BJB, Amateur Radio Tecnician Class License ************************************************ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick <cranswick@........> Subject: Armwaving explanation: Acceleration vs. Displacement Date: Wed, 24 Sep 1997 22:07:48 -0600 Dear PSN- In response to the flurry of email last week on the subject of the response of various kinds damped harmonic oscillators to ground motions, I talked to Larry Cochrane at length late last Thursday night. Here is a summary of some of the cosmic truth that emerged. First of all, I know it is very easy to get lost in the forest of the electrical, electronic, and digital components of a seismograph system, because I have become lost there myself many times, with increasing frequency during the last decade. For that reason, I am going to direct my talk to the single "tree" consisting of a simple pendulum. Get a ruler with a hole at one end. Put a suitable pivot, such as a pen or straightened paper clip, through that hole to suspend the ruler so that it is free to swing. Hold the pivot with your hand, which will constitute the "frame" assumed to be fixed to the Earth. Displacements of the pendulum with respect to the Earth, i.e., the output of the system, will be measured in terms of the offset of the bottom of the ruler with respect to the hand. In other words, with respect to an imaginary line that is fixed to the hand and that initially passes vertically through the hand along the axis of the ruler. Turning and shaking movements of the hand correspond to tilting and translational movements of the Earth. Observe the natural period (1 / frequency) and the damping of the pendulum by holding the pivot fixed in the right hand and giving the pendulum a push with the left hand, i.e., comparable to exciting the pendulum with a calibration coil. Note that the pendulum swings back and forth many times, albeit with diminishing amplitude, which indicates that it is very underdamped. Test the short-period (high-frequency) response of the pendulum by shaking the pendulum, moving your right hand back and forth, much more rapidly than the natural period. Note that the motion of the bottom of the pendulum is equal and opposite to the motion of the top. The amplitude response or offset, i.e., motion of the bottom relative to the top of the pendulum, is proportional to the distance the hand moves, and the phase response or the fraction of a complete cycle that the pendulum lags behind the hand is 180 degrees. In other words, at short periods (high frequencies), the displacement output of the pendulum is proportional to the displacement input, and it exhibits a phase lag of 180 degrees. Test the long-period (low-frequency) response by shaking the pendulum much more slowly than the natural period. Note that motion of the bottom of the pendulum is almost the same as that at the top. There is very little offset of the pendulum (most of the motion is probably caused by a high-frequency tremor of the hand; at least, in my case), and that offset is roughly independent of the distance that you move your hand. Only a small offset is produced, and it exhibits a small phase lag, e.g. only a few degrees at most. Keeping the distance that you move your hand, i.e., the input displacement, constant, slowly increase the speed at which you move your hand, i.e., decrease the period of shaking. The offset will increase with the rate of shaking (frequency) as long as the period of shaking is less than the natural period. I will claim here, without going into the mathematics, that the offset is proportional to the acceleration. Next, consider the response of the pendulum to tilt. Turn the right hand along the axis of the pivot. The pendulum will continue to hang down vertically, but there will have been an offset created because the reference frame, the hand, will have rotated relative to the pendulum. For small tilts or rotation angles, the resulting offset will be proportional to the acceleration due to gravity. If we could horizontally accelerate ourselves at a constant rate while holding the pivot that supports the pendulum, we would observe a constant offset. As an alternate to this fixed horizontal acceleration, apply an equivalent constant force to the pendulum by blowing horizontally against the bottom of it. Note that the pendulum displays a corresponding constant offset that is proportional to how hard you blow, i.e., to the applied force. In this paragraph, we have described the response of the pendulum to what are effectively infinitely long-period (zero frequency) motions. In other words, at long periods (low frequencies), the displacement output of the pendulum is proportional to the acceleration input, and it exhibits a phase lag that approaches zero degrees. So, to summarize in the form of a mantra: In terms of the displacement output, a mechanical harmonic oscillator, e.g., a pendulum or mass on a spring, measures input acceleration at periods longer than the natural period and measures displacement at shorter periods. Or equivalently: In terms of the displacement output, a mechanical harmonic oscillator e.g., a pendulum or mass on a spring, measures input acceleration at frequencies lower than the natural frequency and measures displacement at higher frequencies. Other perspectives on mechanical damped harmonic oscillators: (D) The displacement output, i.e., response, to input displacement is flat above the natural frequency and rolls-off (decays) at 12 dB (2 significant bits) per octave at frequencies below the natural frequency. (V) The velocity output, i.e., response, to input velocity is flat above the natural frequency and rolls-off (decays) at 12 dB (2 significant bits) per octave at frequencies below the natural frequency. (A) The acceleration output, i.e., response, to input acceleration is flat above the natural frequency and rolls-off (decays) at 12 dB (2 significant bits) per octave at frequencies below the natural frequency. Since we customarily sense or measure the velocity of pendulums, i.e., the velocity output, using a magnet and a coil (the voltage induced in the coil is proportional to the velocity of the coil with respect to the magnetic field, i.e., the magnet), we are generally concerned with the case (V) above. Therefore, in order to get the widest band of flat response, i.e., velocity response, we try to use harmonic oscillators with low natural frequencies (long natural periods). Hence, the advantage of 20-s (0.05 Hz) Lehman seismometers with respect to 4.5 Hz (0.2 s) geophones. However, the SG sensor consists of a pendulum with a high natural frequency (nominally higher than the highest frequency of interest), and it is the displacement of the pendulum that is sensed (via capacitance plates often, or in Larry's device, using miniature transmit/receive antennae). The resulting voltage is proportional to pendulum displacement output and is therefore proportional to input (ground) acceleration, and this acceleration signal is then electronically integrated to velocity. Thus the SG sensor has a flat response to ground velocity at frequencies below the natural frequency of the pendulum. In my next attempt to elucidate some of these mysteries of the seismological priesthood, I hope to employ some figures and mathematics. Until then, keep the faith. -Edward -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Karl Cunningham <karlc@.......> Subject: Re: Armwaving explanation: Acceleration vs. Displacement Date: Thu, 25 Sep 1997 08:55:57 -0700 Edward -- Thank you for the very thorough discussion of the pendulum dynamics. Your use of a ruler as a demonstration prop helped a lot. I'm not sure about one of the statements you made: Toward the end you wrote: > (D) The displacement output, i.e., response, to the input displacement is flat >above the natural frequency and rolls-off (decays) at 12 db (2 significant bits) per >octave at frequencies below the natural frequency. > (V) The velocity output, i.e., response, to the input frequency is flat above >the natural frequency and rolls-off (decays) at 12 db (2 significant bits) per octave at >frequencies below the natural frequency. > (A) The acceleration output, i.e., response, to the input acceleration is flat >above the natural frequency and rolls-off (decays) at 12 db (2 significant bits) per >octave at frequencies below the natural frequency. I agree with (D), take issue with (A), and am not sure about (V). I think (A) should be flat BELOW the natural frequency and roll off at 12db/octave ABOVE the natural frequency. For (V), my guess is that response to a constant-frequency stimulus will roll off at 6db/octave both below and above the natural frequency. Thanks again for you detailed explanation. Karl Cunningham La Mesa, CA. PSN station #40 karlc@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: GeE777@....... Subject: Another Armwave Date: Thu, 25 Sep 1997 14:23:33 -0400 (EDT) Dear PSN Geophone: The instrument used to transform seismic energy into an electr= ical voltage; a seismometer, a jug or pickup. Most land geophones are the moving-coil type. A coil is suspended by springs in a magnetic field ( t= he magnet often is integral with the case of the instrument ). A seismic wa= ve moves the case and the magnet but the coil remains relatively stationary because of its inertia. The movement of the magnetic field with respect = to the coil generates a voltage across the coil which is proportional to the difference between the velocity of the coil and the magnet. Thus. over a region which is above the natural frequency, the voltage output is proporational to the velocity of the seismic wave motion and relative insensitive to frequency. At frequencies below the natural frequency of = the geophone, the output ( for input of constant velocity of magnetic moti= on ) is proportional to frequency and hence to the acceleration involved in th= e seismic wave. R. E. Sheriff =91=92 Encyclopedic Dictionary of Explorati= on Geophysics =91=92 p.98 Also see '' Seismic Prospectiog Instruments '' , = By Berlin, Gebruder Borntoeger ( The Doodlebugger's Bible ) George Erich GeE777@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: lahr@................. (Dr. John Lahr (USGS-GI Seismologist)) Subject: response curves Date: Thu, 25 Sep 1997 15:37:35 -0800 > From GeE777@....... Thu Sep 25 10:23:49 1997 > Date: Thu, 25 Sep 1997 14:23:33 -0400 (EDT) > Subject: Another Armwave > > Dear PSN > > Geophone: .... > ... At frequencies below the natural frequency of the > geophone, the output ( for input of constant velocity of magnetic motion ) > is proportional to frequency and hence to the acceleration involved in the > seismic wave. R. E. Sheriff, Encyclopedic Dictionary of Exploration > Geophysics, p.98 Also see '' Seismic Prospectiog Instruments '' , By > Berlin, Gebruder Borntoeger ( The Doodlebugger's Bible ) > > George Erich > GeE777@....... I disagree with this last part. I'll try some Email graphs, which may or may not help! Starting with Ed's discussion of a simple pendulum, we know that the displacement of the pendulum is proportional to the displacement of the ground above the natural frequency of the pendulum and proportional to the acceleration below this frequency (fo). Below is a graph of the ratio of the displacement of the pendulum bob divided by the displacement of the ground as a function of frequency. This plot could be generated by a shake table on which the pendulum was mounted. The shake table would be vibrated back and forth at a constant amplitude at "frequency 1" and the amplitude of the pendulum motion would be measured. Then the frequency would be changed to "frequency 2," and the pendulum amplitude measured again. This would be continued for all frequencies of interest, always keeping the amplitude of the shake table motion constant. If for each frequency, the ratio of the pendulum amplitude to the shake table amplitude were measured, the following plot could be generated: (1) | | | ___________________ Displacement of Pendulum | / ________________________ | / | / Displacement of Ground | / f**2 | / | / | / _______________________________________ "flat to displacement" fo FREQUENCY From this one plot, all other response plots for simple pendulums can be generated if one keeps in mind the relationship between displacement, velocity, and acceleration. If the displacement, D, is given by D = A sin (2 pi f t), where f is the frequency, t is time, and A is a constant, then velocity = 2 pi f A cos(2 pi f t) Note that the amplitude of the velocity increases as f. acceleration = -4 pi**2 f**2 sin(2 pi f t) Note that the acceleration increases as f squared (f**2). So, consider what the curve above would look like if the velocity of the pendulum were measured rather than the amplitude. This would add a factor of f to the numerator because the derivative of the displacement is the velocity: (2) | f _ | _ - | - Velocity of Pendulum | / ________________________ | | / Displacement of Ground | f**3 | / | | / _______________________________________ fo FREQUENCY Next consider the velocity of the pendulum with respect to the velocity of the ground. Since the velocity of the ground is the derivative of the displacement of the ground, this adds a factor of f to the denominator and the curve becomes: (3) | | | ___________________ Velocity of Pendulum | / ________________________ | / | / Velocity of Ground | / f**2 | / | / | / _______________________________________ "flat to velocity" fo FREQUENCY One can further take the derivative of the velocity of the ground to get the velocity response to acceleration: (4) | | | . Velocity of Pendulum | - - ______________________ | - - - - Acceleration of ground - | f 1/f - | | | _______________________________________ fo FREQUENCY The next curve, displacement versus acceleration, can be thought of as the result of integrating the numerator in the velocity versus acceleration curve just above, causing the ratio to be divided by f, or as the result of starting with the displacement versus displacement curve (Curve 1) and taking the second derivative of the denominator, which causes that ratio to be divided by f**2. In either case the result is the same: (5) | | | ___________ Displacement of Pendulum | \ ________________________ | \ | \ Acceleration of ground | \ 1/f**2 | \ | \ | \ _____________________________ "flat to acceleration" fo FREQUENCY Since there are three ways one could measure the pendulum motion (displacement, velocity, or acceleration) and three ways to view the ground motion (displacement, velocity, or acceleration) there are nine ways to plot the response of a simple pendulum. Contrary to the Encyclopedia article, for f < fo the output of a velocity transducer is proportional to the derivative of the acceleration, not the acceleration. JCLahr ################################## John C. Lahr ################################# Seismologist ################################ U.S. Geological Survey ############################### c/o Geophysical Institute ############################## 903 Koyukuk Drive ~~~~~~~~~~~~~~ Get ~~~~~~~~~~ ############################# ########################################################### P.O. Box 757320 ################################ Fairbanks, AK 99775 ################################# Phone: (907) 474-7997 ################################## Fax: (907) 474-5618 ~~~~~~~~ the thrust? ~~~~~~~~~~~~~~ lahr@........ #################################### http://www.aeic.alaska.edu/Input/lahr/ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Doug Crice <dcrice@............> Subject: Re: response curves Date: Thu, 25 Sep 1997 18:23:06 -0700 >Contrary to the Encyclopedia article, for f < fo the output of a >velocity transducer is proportional to the derivative of the >acceleration, not the acceleration. >JCLahr That's pretty insightful. I can't wait till I see Bob Sheriff in November at the Society of Exploration Geophysicists meeting to tell him he messed up. Another more simplistic way is to look at the response curves. If the geophone is flat (relative to ground velocity) above the natural frequency and rolls off at 12 db/octave below the corner (as opposed to 6 db/octave), it must be a second order system and be proportional to the second derivative (jerk) not the first derivative (acceleration). Doug Crice _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Francesco" <donjuan@......> Subject: MEDIUM QUAKE IN CENTRAL ITALY Date: Fri, 26 Sep 1997 04:03:36 +0200 have someone registred medium quake occorred 1 hour ago in central italy? Primary response by ING: 5,2 Ms Best regards Francesco Nucera - Ancona - Italy _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson <dann@........> Subject: Re: MEDIUM QUAKE IN CENTRAL ITALY Date: Fri, 26 Sep 1997 16:03:37 +1200 Francesco, the USGS/NEIC report... 97/09/26 00:33:11 42.81N 12.58E 10.0 5.5Ms CENTRAL ITALY Ms 5.5 a respectable event in countries like yours with a lot of old stone work buildings a quake of this size can be disasterous. Dave PS lets hear from our two Itilian PSN members with recording gear...... have you files to upload for all to see At 04:03 AM 9/26/97 +0200, you wrote: >have someone registred medium quake occorred 1 hour ago in central italy? >Primary response by ING: 5,2 Ms >Best regards >Francesco Nucera - Ancona - Italy Co-ordinator: New Zealand Public Seismic Network Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson <dann@........> Subject: Re: response curves Date: Fri, 26 Sep 1997 16:07:11 +1200 At 06:23 PM 9/25/97 -0700, you wrote: >Another more simplistic way is to look at the response curves. If the >geophone is flat (relative to ground velocity) above the natural >frequency and rolls off at 12 db/octave below the corner (as opposed to >6 db/octave), it must be a second order system and be proportional to >the second derivative (jerk) not the first derivative (acceleration). > >Doug Crice Doug and Co, excuse my ignorance please confirm when you say e.g. 12dB/ octave do you mean 12dB/ every 8Hz seen the expression so often over the years just want to confirm that I have the correct meaning Dave Co-ordinator: New Zealand Public Seismic Network Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: GeE777@....... Subject: Re: response curves Date: Fri, 26 Sep 1997 01:25:34 -0400 (EDT) Hello PSN In a message dated 97-09-25 21:31:38 EDT, Doug writes: << I can't wait till I see Bob Sheriff in November at the Society of Exploration Geophysicists meeting to tell him he messed up. >> Sheriff was quoting Evenden, Stone and Anstey Some of my tests-- I used a DC voltage to offset the coil of a geophone from it's normal at rest position. When this voltage is removed, a spike is generated by the collapsing EMF. Following the spike, is a wavelet caused by the coil moving through the magnetic field to its at rest position. This wavelet is the geophone step function response. ( I have built a switch that allows this wavelet to be recorded but not the DC voltage or the spike. ) When the second derivative of this wavelet is ploted, it fits with the plots of the frequency response curves provided by the geophone manufactures. OUTPUT (V/in/sec) vs frequency Coil/case displacement limit is usually provided with geophone specifications. A typical geophone would have .06 in. (.15 cm ) When enough voltage is applied to the coil to offset it to the maximum displacement position, .03 in. in the typical geophone, the resultant step function response can be used to determine the sensitivity of the geophone. Discussion encouraged George Erich GeE777@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick <cranswick@........> Subject: Re: response curves Date: Fri, 26 Sep 1997 00:05:21 -0600 John- Thank you for the graphics and the math! -Edward Dr. John Lahr (USGS-GI Seismologist) wrote: .... > I disagree with this last part. I'll try some Email graphs, which may or > may not help! > > Starting with Ed's discussion of a simple pendulum, .... -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 PO Box 25046, Federal Center cranswick@........ Denver, CO 80225-0046 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane <cochrane@..............> Subject: Re: 12db/octave Date: Thu, 25 Sep 1997 22:12:53 -0700 At 04:07 PM 9/26/97 +1200, Dave Nelson wrote: > Doug and Co, > excuse my ignorance please confirm when you >say e.g. 12dB/ octave > > do you mean 12dB/ every 8Hz seen the expression so often over the >years just want to confirm that I have the correct meaning > An octave is simply the doubling of frequency. A 200 hz signal is one octave higher then 100hz. So... if you have a 1 volt peek to peek (vpp) signal at say 10 hz then at 20 hz the signal will be down to 0.250 vpp, if the filter (or pendulum, whatever) has a 12 db/octave attenuation. Another way of putting it is the voltage will be 4 times less (or more if we are dealing with gain and not attenuation) per octave. At 6 db/octave the voltage is 2 times more/less and at 3 db/octave the voltage change will be ..707. -Larry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Dott. Roberto E. Pozzo" <repnizza@...........> Subject: Re: MEDIUM QUAKE IN CENTRAL ITALY Date: Fri, 26 Sep 1997 11:52:34 +0200 Francesco wrote: > > have someone registred medium quake occorred 1 hour ago in central italy? > > Primary response by ING: 5,2 Ms > > Best regards > > Francesco Nucera - Ancona - Italy > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L Here in Piedmont , the main shock from Central Italy has saturated 4-5 minutes of my long T recording ! M. 5.5 VIII M.C.S. Only for information : by now 2 victims (buried by their old house ), many structural damages in regions of Marche and Umbria , in Rome also, some very little damage reported. roberto Nizza Monferrato - Italy - P.S.N _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Giovanni Rotta" <rottag@..........> Subject: Central Italy quake at 13.30 UTC Ml 4.6 Date: Fri, 26 Sep 1997 16:01:48 +0200 Hi all ! one quake more in Central Italy, 13:30 UTC, Ml. 4.6, 441 Km. from my station. Someone chek it ? Giovanni Giovanni Rotta rottag@.......... Via F. Pizzigoni, 10 33010 Resia (Udine) Italy Lat. 46.22N Long. 13.18E _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson <dann@........> Subject: Re: Central Italy quake at 13.30 UTC Ml 4.6 Date: Sat, 27 Sep 1997 02:17:20 +1200 Giovanni, how about uploading somefiles of the events for us to look at in winquake Dave At 04:01 PM 9/26/97 +0200, you wrote: >Hi all ! >one quake more in Central Italy, 13:30 UTC, Ml. 4.6, 441 Km. from my >station. >Someone chek it ? >Giovanni > >Giovanni Rotta >rottag@.......... >Via F. Pizzigoni, 10 >33010 Resia (Udine) Italy >Lat. 46.22N Long. 13.18E > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > Co-ordinator: New Zealand Public Seismic Network Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson <dann@........> Subject: Italy quakes Date: Sat, 27 Sep 1997 03:32:57 +1200 the second event even bigger than the first USGS/NEIC 97/09/26 09:40:25 42.97N 12.84E 10.0 5.9Ms CENTRAL ITALY Dave Co-ordinator: New Zealand Public Seismic Network Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Doug Crice <dcrice@............> Subject: Re: response curves Date: Fri, 26 Sep 1997 08:43:51 -0700 Dave: Octave is music talk. There are 8 notes on a music staff from A to G then the cycle repeats. So, say you have an "A" which is 440 Hz. The next "A" is 880 and then again at 1760 Hz. So, an "octave" change is frequency is either double or half the original. The electronics folks adopted the term to mean the same thing. Signal amplitude changes can be measured in volts or decibels (dB). The equation is 20*log10 (v2/v1). Since log10 of 2 or 1/2 is .3 or -.3, the double of half the original amplitude is +6 or -6 db. Frequency dependent attenuation or amplification depends on what the electrical engineers call active elements (capacitors and inductors). The physicists use things like pendulums to make mechanical systems with frequency dependent characteristics. Mathematicians use integrals and derivatives to represent the same thing. Every "active element" will change the slope of the frequency response by some multiple of 6 dB/octave (e.g. 12, 18, 24), but then you knew all that. There are no in-between slopes except around the resonant frequencies, so you can't make a slope of -9 dB/octave. Doug _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Kees Verbeek <kverb@........> Subject: Re: Central Italy quake at 13.30 UTC Ml 4.6 Date: Fri, 26 Sep 1997 17:53:26 +0200 (MET DST) >Someone chek it ? >Giovanni > Giovanni, Got them over here in holland, Hope the damage isn't to big The damage in my recorder is that i lost my pen on them , so that's not so much of a problem!!!!!! It are "good" quakes to adjust and tune my instrument ,although that's a strange story with so much damage over there. My timeclock isn,t alright i had it just before 13.31.18. greetings, (Europe is talking) Kees Verbeek. Holland _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson <dann@........> Subject: Re: response curves Date: Sat, 27 Sep 1997 04:21:45 +1200 Doug, Thanks for your response, between yours and Larry's I managed to sort that out. Music.... yes that is where I was first introduced to the term octave.... played cornet in a brass band for 10 years but not for some years now. I was going to also query the comment about 6dB being double the gain.... thinking no that is wrong 3dB is x2 6dB is x4 until I remembered we are talking about voltage gain(loss) not power. As a radio tech. I work with power gain when working with transmitter and antenna gain when the above applies 3 = x2, 6 =x4 .... 10dB =x10, 20dB = x100 etc it is a trap, when one have been exposed to one field of electronics for so many years, one can be quite ignorant of formula and theories (sometimes very basic concepts) in another field. TNX again Dave At 08:43 AM 9/26/97 -0700, you wrote: >Dave: > >Octave is music talk. There are 8 notes on a music staff from A to G >then the cycle repeats. So, say you have an "A" which is 440 Hz. The >next "A" is 880 and then again at 1760 Hz. So, an "octave" change is >frequency is either double or half the original. The electronics folks >adopted the term to mean the same thing. > >Signal amplitude changes can be measured in volts or decibels (dB). The >equation is 20*log10 (v2/v1). Since log10 of 2 or 1/2 is .3 or -.3, the >double of half the original amplitude is +6 or -6 db. > >Frequency dependent attenuation or amplification depends on what the >electrical engineers call active elements (capacitors and inductors). >The physicists use things like pendulums to make mechanical systems with >frequency dependent characteristics. Mathematicians use integrals and >derivatives to represent the same thing. > >Every "active element" will change the slope of the frequency response >by some multiple of 6 dB/octave (e.g. 12, 18, 24), but then you knew all >that. There are no in-between slopes except around the resonant >frequencies, so you can't make a slope of -9 dB/octave. > >Doug Co-ordinator: New Zealand Public Seismic Network Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson <dann@........> Subject: Aurora Alert Date: Sat, 27 Sep 1997 04:27:46 +1200 ok you bods in the western Hemis. particurlarly the USA and mid to High latitude its 0400 local time 27 sept (1600utc 26Sept.) I have only 3 hrs of dark left and the auroral storming has yet to start it is not too far away as soon as it is dark in your region keep an eye out to the north I ain't going to bed till the sun rises (no I'm not a vampire) I just love viewing and photographing aurora Cheers Dave Co-ordinator: New Zealand Public Seismic Network Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Lloyd Verhage" <verhage@.............> Subject: Re: Aurora Alert Date: Fri, 26 Sep 1997 11:41:44 CST6CDT I'm not certain, but I may have seen one last night. This is from northern Kansas. > ok you bods in the western Hemis. particurlarly the USA and mid to High > latitude > > its 0400 local time 27 sept (1600utc 26Sept.) I have only 3 hrs of dark > left and the auroral storming has yet to start it is not too far away as > soon as it is dark in your region keep an eye out to the north _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: lahr@................. (Dr. John Lahr (USGS-GI Seismologist)) Subject: Here's the focal mechanis for the event in Italy Date: Fri, 26 Sep 1997 10:08:46 -0800 This indicates normal faulting on a NW-striking plane for the first of today's two Italian quakes. JCLahr ################################## John C. Lahr ################################# Seismologist ################################ U.S. Geological Survey ############################### c/o Geophysical Institute ############################## 903 Koyukuk Drive ~~~~~~~~~~~~~~ Get ~~~~~~~~~~ ############################# ########################################################### P.O. Box 757320 ################################ Fairbanks, AK 99775 ################################# Phone: (907) 474-7997 ################################## Fax: (907) 474-5618 ~~~~~~~~ the thrust? ~~~~~~~~~~~~~~ lahr@........ #################################### http://www.aeic.alaska.edu/Input/lahr/ > From autocmt@........................ Thu Sep 25 19:28:57 1997 > Date: Fri, 26 Sep 97 11:51:48 JST > From: autocmt <autocmt@........................> > To: globalCMT@........................ > Subject: ERI AUTOCMT 9/26 CENTRAL ITALY (ms 5.5) > > * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * > * Following is a CMT solution automatically determined using a method very * > * similar to that developed by the Harvard group. * > * The solution is not checked by anyone at ERI and when the variance * > * reduction is below 10% or the station coverage is bad, it is often * > * unreliable. * > * * > * If you have any question or complaint, please contact * > * hitosi@................. * > * Hitoshi Kawakatsu * > * Earthquake Research Institute * > * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * > ------------------------- ERI automatic CMT inversion ------------------------- > CENTRAL ITALY (ms 5.5) > 1997-09-26 00:33:11.8 (QED) Mo=5.16**24(dyne-cm) Mw=5.7 > lat: 42.80 lon: 12.60 dep: 10.0 (QED) > Data: bodywave [10,12,20,22mHz] ############ > coverage: 0- 60- 120- 180- 240- 300- ------############## > z-comp: 0 0 0 1 1 0 --------------############ > r-comp: 0 0 0 1 1 0 #------------------########### > t-comp: 0 0 0 1 1 0 ##--------------------########## > Variance Reduction 27.2% of 6 records ###----------- --------######### > CMT solution: unit in 1e+24 (dyne-cm) #####---------- P ---------######### > lat: 43.22 lon: 12.58 dep: 25.2 (CMT) #####---------- ----------######## > Mrr: -4.98 +- 1.34 Mrt: -0.64 +- 1.59 #######----------------------####### > Mtt: 2.16 +- 2.31 Mrf: -0.50 +- 0.95 ########---------------------####### > Mff: 2.82 +- 1.12 Mtf: -2.70 +- 0.57 #########--------------------##### > T-axis Val= 5.21 Plg= 0.3 Azm = 228.4 # #######-----------------#### > N-axis Val= -0.09 Plg= 9.4 Azm = 138.4 T ##########-------------#### > P-axis Val= -5.11 Plg= 80.6 Azm = 320.3 #################-------- > Best Double Couple: Mo=5.16**24 Mw=5.7 #################### > nodal planes (strike/dip/slip): ############ > 327.8/ 45.5/-76.7 129.2/ 46.1/-103.1 Fit is GOOD (27% of 6 records) > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: lahr@................. (Dr. John Lahr (USGS-GI Seismologist)) Subject: Second Italian Shock Date: Fri, 26 Sep 1997 10:19:38 -0800 This shock, which I hope is the main shock, has a very similar mechanism to the first one -- normal faulting on a NW-trending fault. JCLahr ################################## John C. Lahr ################################# Seismologist ################################ U.S. Geological Survey ############################### c/o Geophysical Institute ############################## 903 Koyukuk Drive ~~~~~~~~~~~~~~ Get ~~~~~~~~~~ ############################# ########################################################### P.O. Box 757320 ################################ Fairbanks, AK 99775 ################################# Phone: (907) 474-7997 ################################## Fax: (907) 474-5618 ~~~~~~~~ the thrust? ~~~~~~~~~~~~~~ lahr@........ #################################### http://www.aeic.alaska.edu/Input/lahr/ > From autocmt@........................ Fri Sep 26 04:52:48 1997 > Date: Fri, 26 Sep 97 21:16:33 JST > From: autocmt <autocmt@........................> > To: globalCMT@........................ > Subject: ERI AUTOCMT 9/26 CENTRAL ITALY (ms 5.9) > > * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * > * Following is a CMT solution automatically determined using a method very * > * similar to that developed by the Harvard group. * > * The solution is not checked by anyone at ERI and when the variance * > * reduction is below 10% or the station coverage is bad, it is often * > * unreliable. * > * * > * If you have any question or complaint, please contact * > * hitosi@................. * > * Hitoshi Kawakatsu * > * Earthquake Research Institute * > * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * > ------------------------- ERI automatic CMT inversion ------------------------- > CENTRAL ITALY (ms 5.9) > 1997-09-26 09:40:25.3 (QED) Mo=8.07**24(dyne-cm) Mw=5.9 > lat: 43.00 lon: 12.80 dep: 10.0 (QED) > Data: bodywave [10,12,20,22mHz] ############ > coverage: 0- 60- 120- 180- 240- 300- #################### > z-comp: 2 0 0 4 1 0 ##----------############## > r-comp: 2 0 0 4 1 0 ###---------------############ > t-comp: 2 0 0 4 1 0 ####------------------########## > Variance Reduction 18.0% of 21 records #####---------------------######## > CMT solution: unit in 1e+24 (dyne-cm) #######---------- --------######## > lat: 42.89 lon: 13.09 dep: 10.0 (CMT) #######---------- P ----------###### > Mrr: -7.59 +- 0.59 Mrt: 0.04 +- 0.32 ########--------- -----------##### > Mtt: 3.20 +- 0.32 Mrf: 0.94 +- 0.41 #########----------------------##### > Mff: 4.39 +- 0.62 Mtf: -4.59 +- 0.58 ##########---------------------### > T-axis Val= 8.45 Plg= 2.4 Azm = 228.9 # #######-------------------## > N-axis Val= -0.77 Plg= 5.4 Azm = 319.1 T #########-----------------# > P-axis Val= -7.68 Plg= 84.0 Azm = 114.9 ############------------- > Best Double Couple: Mo=8.07**24 Mw=5.9 #################--- > nodal planes (strike/dip/slip): ############ > 313.2/ 42.8/-98.0 144.1/ 47.7/-82.6 Fit is REASONABLE (18% of 21 records) > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Kees Verbeek <kverb@........> Subject: Re: Central Italy quake at 13.30 UTC Ml 4.6 Date: Fri, 26 Sep 1997 20:26:06 +0200 (MET DST) Hi all, I've just seen some images on t.v. from Italie , That where some real Quakes ,a lot off damage and disaster over there. Something to think about when our instruments are "peaking"!!!!!! greetings, Kees Verbeek _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: DSeeber101@....... Subject: Re: response curves Date: Fri, 26 Sep 1997 18:48:19 -0400 (EDT) Actually Doug, there are 12 notes in a musical octave, if you count the sharps & flats. (black keys) The freq of each note on the so called even tempered scale is the 12th root of 2 times higher than the previous note. That makes up the octave after 12 notes. Sorry to get so far afield. Don Sieber dseeber101@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jim Hannon <jmhannon@........> Subject: Re: response curves Date: Fri, 26 Sep 1997 18:23:22 -0500 DSeeber101@....... wrote: > > Actually Doug, there are 12 notes in a musical octave, if you > count the sharps & flats. (black keys) The freq of each note on the > so called even tempered scale is the 12th root of 2 times higher than > the previous note. That makes up the octave after 12 notes. > Sorry to get so far afield. > > Don Sieber > dseeber101@....... > -- This could go on forever :) I am not a music theory expert but there are lots of instruments that only play 8 notes per octave and when you play a scale you play 8 notes per ocatve. The key of the scale determining which notes are played. The 12th root of two being only an approximation to the correct spacing of each note in the scales. Jim Hannon http://soli.inav.net/~jmhannon/ 42,11.90N 91,39.26W WB0TXL _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Al Allworth <aallworth@........> Subject: Re: response curves Date: Fri, 26 Sep 1997 21:00:20 -0700 (PDT) At 08:43 AM 9/26/97 -0700, you wrote: >Dave: > >Octave is music talk. There are 8 notes on a music staff from A to G >then the cycle repeats. So, say you have an "A" which is 440 Hz. The >next "A" is 880 and then again at 1760 Hz. So, an "octave" change is >frequency is either double or half the original. The electronics folks >adopted the term to mean the same thing. > >Signal amplitude changes can be measured in volts or decibels (dB). The >equation is 20*log10 (v2/v1). Since log10 of 2 or 1/2 is .3 or -.3, the >double of half the original amplitude is +6 or -6 db. > >Frequency dependent attenuation or amplification depends on what the >electrical engineers call active elements (capacitors and inductors). >The physicists use things like pendulums to make mechanical systems with >frequency dependent characteristics. Mathematicians use integrals and >derivatives to represent the same thing. > Should this be: reactive elements? Active elements are like transistors, IC's etc. All others are passive and can be reactive or ohmic (resistors). Not so???????? >Every "active element" will change the slope of the frequency response >by some multiple of 6 dB/octave (e.g. 12, 18, 24), but then you knew all >that. There are no in-between slopes except around the resonant >frequencies, so you can't make a slope of -9 dB/octave. > >Doug > > > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > ____________________________________________________________________________ Al Allworth, Gold Beach, OR aallworth@........ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson <dann@........> Subject: still waiting!!! Date: Sun, 28 Sep 1997 00:18:37 +1200 hi all, well still waiting for this shockwave to hit earth, it has now turned into what they call a tardy event. unfortunately it is not the very clear nite like last nite a lot of scattered cloud. But I'm still living in hope of seeing the arrival. 5MHz WWV is still quite fluttery with radio aurora. chow Dave Co-ordinator: New Zealand Public Seismic Network Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz <gbl@.......> Subject: Re: response curves Date: Fri, 26 Sep 1997 18:15:13 -0700 All One thing I may add to John's excellent discussion is that damping modifys the curve shape around the natural frequency. Ideally ,at about 70% critical there is a smooth but abrupt rollover at the natural frequency. For larger damping the curve transition is more sweeping and gradual. With less damping you begin to develop a peak whose amplitude goes to "infinity" as the damping approaches zero. Without adjusting circuitry, one then tries to stay in the flat or constant amplitude range with their sensor. I think that the integrator in the SG sensor flattens out the low frequency dropoff in the displacement curve, increasing the sensors low frequency range; however , a low freq amplitude ceiling is set by a coupling DC coupling cap in the circuit. Barry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Erich F. Kern" <ekern@.........> Subject: Re: still waiting!!! Date: Sat, 27 Sep 1997 11:07:06 -0700 Hi Dave, At 1030 local time (1730 UTC) 9/27/97 my magnetometer is showing a higher peak in activity than we had here 21 hours ago yesterday, so there'll be another chance at aurora. Did you get the 3 maps alright? Whadda you think of the Humphrey accelerometers? If you think we're wasting our time I can accept an honest opinion! Regards, Erich *************************************************************** Please visit our web site at: http://www.dconn.com/FatQuartersSoftware Thank you *************************************************************** ---------- > From: David A Nelson <dann@........> > To: psn-l@............. > Subject: still waiting!!! > Date: Saturday, September 27, 1997 05:18 > > hi all, > well still waiting for this shockwave to hit earth, it has now > turned into what they call a tardy event. unfortunately it is not the very > clear nite like last nite a lot of scattered cloud. But I'm still living > in hope of seeing the arrival. 5MHz WWV is still quite fluttery with radio > aurora. > > chow > Dave > > Co-ordinator: > New Zealand > Public Seismic Network > Dave A. Nelson > 24 Jensen St., > Green Is., Dunedin, > South Is.. New Zealand. > > http://psn.quake.net/dave/home.htm > > IF there indeed are other parallel universes... I can now rest in the > knowledge, that in at least one of them, I am filthy rich and drive a red > Ferrari > > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Stephen Paul <spaul@............> Subject: Re: Files sent to event@............. and the NewEvent mailing Date: Sun, 28 Sep 1997 02:59:16 -0700 David A Nelson wrote: > Larry, > I have been working with Frank over the last couple of days > about the operations of winquake and also on the file size I had also said > to him about cutting down the sample rate to 12.5 or 25 sps > > Stephen was definately a bit harsh.... as it was Franks first posting and > everyone is allowed a few mistakes until they learn to get a handle on SDR > and Winquake. > > as I said to Frank in private mail Keep up the good work experiment > with the sample rate, and the different WQ tools and we hope to see more > postings > > Dave N. > > At 01:31 AM 9/23/97 -0700, you wrote: > >Stephen, > > > >It looks like you shouldn't be a member of the NewEvent mailing list. When > >PSN stations want to upload event files for archiving on my system they > >send then, as attachments, to the event@............. address. The same > >email message, along with the attachment, is forwarded to the > >NewEvent@......... mailing list so others can receive the event files > >directly. > > > >Frank's file was a bit larger then normal, and, I have asked him to cut > >down on the file size by reducing the sample rate. But on an active day you > >can expect a lot of event files will over the 650k. > > > >As far as unsolicited files... didn't you subscribe to the NewEvent list? > >If not I will remove you. > > > >-Larry Cochrane > >Redwood City, PSN > > > > Co-ordinator: > New Zealand > Public Seismic Network > Dave A. Nelson > 24 Jensen St., > Green Is., Dunedin, > South Is.. New Zealand. > > http://psn.quake.net/dave/home.htm > > IF there indeed are other parallel universes... I can now rest in the > knowledge, that in at least one of them, I am filthy rich and drive a red > Ferrari > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L Dave I tried to be welcoming and understanding, I'm sorry if I seemed harsh. I apologize to all who thought my comments out of line. I was just tired of leaving for a few days and having to take 40 min. to get my mail, that's all. This used to be more of a discussion group, and a reporting group. It seems many of us have stopped conversing, and must stick large attachments on a lot of the mail. I didn't know that this was unreasonable. However, without my asking, Larry has evidentally seen to it that I shall trouble you no further, as he treated my request as an unsubscribe. So be it. Sorry. -- Stephen :^) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Stephen Paul <spaul@............> Subject: Reply Date: Sun, 28 Sep 1997 03:15:26 -0700 Larry, I signed up for this list, and avidly followed it before these enormous d/ls began, and it was mostly people discussing their hobbies, not putting files this size in my mailbox! When I d/l 57 messages, I'm sorry, but I think there should be something separate for he big files. I got another one tonight that took ten minutes until I could retrieve the rest of my mail. I do think that it's excessive, and is not like the earlier days. If you must remove me, and you feel this is justified on the basis of defending these sizable chunks of mail, and I stand alone, then so be it. One of us want to participate in the hobby in different ways. Myself as a forum for advancing people's home-brews etc. NOT as a venue for crippling downloads that were -not- a part of what was a most enjoyable list. It seems some proportion has gone out of the whole thing, and people hover around like vultures waiting for that next big shock to cal their Lehmans. Living in LA I can tell you it is well to keep in mind that there are -people- living (or were) in some of those places, and while I comprehend the enthusiasm, and have enjoyed a few really good ones myself, and am most interested in keeping tabs on the situation, I do feel it has become indecorous at times as everyone focuses on the event, sometimes forgetting that something really terrible might've happened to some of their fellow humans. Sorry if I offend. But Once More I say, it would be nice to return to the old days, not encourage this logjam of the new. If that is your position, then yes, regretfully, since there is apparently no more room for a slightly more casual reader, then by all means, remove me. Thank you, -- Stephen Paul _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Stephen Paul <spaul@............> Subject: Reply on D/L s Date: Sun, 28 Sep 1997 03:16:40 -0700 Dave I tried to be welcoming and understanding, I'm sorry if I seemed harsh. I apologize to all who thought my comments out of line. I was just tired of leaving for a few days and having to take 40 min. to get my mail, that's all. This used to be more of a discussion group, and a reporting group. It seems many of us have stopped conversing, and must stick large attachments on a lot of the mail. I didn't know that this was unreasonable. However, without my asking, Larry has evidentally seen to it that I shall trouble you no further, as he treated my request as an unsubscribe. So be it. Sorry. - Stephen :^) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz <gbl@.......> Subject: Re: Reply Date: Sat, 27 Sep 1997 21:38:28 -0700 All Just a thought on file size again. If one runs a FFT on their file and determines the maximum frequency with any magnitude. Setting the sample rate to 3-4 times that frequency will give at least 3-4 pts/cycle on the highest frequency of concern. On the other comment Stephen made, I have thought often about people killed or injured by quakes I/we have recorded. The thought of the distruction that an event can bring saddens me. I am an an engineer and way I rationalize (when I feel the need to) my interest in seismology is to say ,as others have said, that in the majority of cases that I can think of "structures kill people not earthquakes". I consider earthquakes part of the heartbeat of the planet. We have stethoscopes. Barry Stephen Paul wrote: >.... NOT as a venue for crippling downloads that > were -not- > a part of what was a most enjoyable list. > > It seems some proportion has gone out of the whole thing, and people > hover > around like vultures waiting for that next big shock to cal their > Lehmans. > Living in LA I can tell you it is well to keep in mind that there are > -people- > living (or were) in some of those places, and while I comprehend the > enthusiasm, > and have enjoyed a few really good ones myself, and am most interested > in > keeping tabs on the situation, I do feel it has become indecorous at > times as > everyone focuses on the event, sometimes forgetting that something > really > terrible might've happened to some of their fellow humans. > > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Stephen Paul <spaul@............> Subject: Re: Reply Date: Sun, 28 Sep 1997 12:47:59 -0700 barry lotz wrote: > All > Just a thought on file size again. If one runs a FFT on their file > and determines the maximum frequency with any magnitude. Setting the > sample rate to 3-4 times that frequency will give at least 3-4 pts/cycle > on the highest frequency of concern. > On the other comment Stephen made, I have thought often about > people killed or injured by quakes I/we have recorded. The thought of > the distruction that an event can bring saddens me. I am an an engineer > and way I rationalize (when I feel the need to) my interest in > seismology is to say ,as others have said, that in the majority of cases > that I can think of "structures kill people not earthquakes". I consider > earthquakes part of the heartbeat of the planet. We have stethoscopes. > > Barry > > Stephen Paul wrote: > >.... NOT as a venue for crippling downloads that > > were -not- > > a part of what was a most enjoyable list. > > > > It seems some proportion has gone out of the whole thing, and people > > hover > > around like vultures waiting for that next big shock to cal their > > Lehmans. > > Living in LA I can tell you it is well to keep in mind that there are > > -people- > > living (or were) in some of those places, and while I comprehend the > > enthusiasm, > > and have enjoyed a few really good ones myself, and am most interested > > in > > keeping tabs on the situation, I do feel it has become indecorous at > > times as > > everyone focuses on the event, sometimes forgetting that something > > really > > terrible might've happened to some of their fellow humans. > > > > > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L Dear Barry: I appreciate your thoughts on the FFT question, I do understand the problem there, as regardless of your window, -or- the number of bins or their dynamic range, Nyquist is truly insufficient to acuire accurate data as we near the highest boundary frequency of interest. Thus things can get large, even if zipped, though I do not know if that is a common practice as it is in other transfer situations. I think the real problem, as explained to me by both Dave and Barry (Lotz), is that unbeknownst to me, (I'm pretty sure I only registered for the chat list) somehow I was receiving from the event server. My suggestion would be, as I really would love to have a copy of Winquake and d/l those event files and learn from them, is that if it was packaged as a newsgroup, I could d/l my mail when I'm in a hurry, and then choose at my leisure to get the big stuff. That would solve the problem for me. I don't know if that's feasible or desireable to anyone else, but it sure would fix my problem. If it is practical, then it would certainly do a lot more good to explain the two lists to me, and try to work something out that's a win-win rather than just terminating my subscription to PSN when I never asked for that to be the answer. If I knew it was not possible or too expensive or whatever to do it as a newsgroup, well, I know of no other way to separate it from my mail... And as I have said before, I never, ever meant to hurt Frank's feelings or any of that. I welcomed him before I said anything. I also know I'm not the first to mention the jamup, but those people (?) person (?) have been strangely silent through all of this. I am glad that you do think of the result as something other than a blip on the screen. I live in LA, and when we have a major event here, well, it's not real pretty. I look at a condemned building every day that was an apartment bldg. before our last shaker, and I look at it out the window of my office. There but for the Grace of God went we. And until those stethoscopes can get people out in time, (which day must surely come, and that is exactly why these lists have my full support), I do think it is important to remember that a good calibration may be bought at the expense of lives and homes. Again, thanks for the thoughts, and to all those who have written me privately, thank-you for your understanding. Keep up the good work, and maybe one day, no one need die, even if they lose their home. Sincerely, -- Stephen :^) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: John Hernlund <hernlund@.......> Subject: New station soon Date: Sun, 28 Sep 1997 15:20:26 -0700 (MST) Hello All, Very soon (within the next couple of weeks) I will have a new station up and running at Arizona State University in Tempe, AZ. The station will consist of a NW-SE Geotech (Lehman type) and a vertical Geotech (boom and spring type). They used to run an ink and paper unit here and were able to pick up some very nice readings in the past. I am going to upload event files w/comments to our web server (I'll post the address when it is set up). I will also be playing with a second horizontal component some time in the near future for experimenting and would like to find some good references on building a force-balance unit. If anyone has any good references on this topic, please e-mail me at the address below. ****************************************************************************** John Hernlund E-mail: hernlund@....... WWW: http://www.mc.maricopa.edu/academic/phy_sci/Geology/hernlund/ ****************************************************************************** _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane <cochrane@..............> Subject: Re: More on SG sensor testing. Date: Sun, 28 Sep 1997 16:09:09 -0700 At 09:10 AM 9/24/97 -0400, you wrote: >Larry, > I'm reading the e-mail which accumulated during a vacation in Los Alamos >where my daughter is doing a post-doc in microbiology at the labs. (If you >want to read some weird stuff, try her web page >www-ls.lanl.gov/~sbarns/crenarchaeota.html The www-ls is correct but was >something new to me.) Had a fine time-rode the narrow-gage train from >Durango to Silverton (CO) again, a trip I can recommend. Your daughters research looks very interesting.... > I found your shake table work and the subsequent messages very >interesting. The use of a stepping motor was a slick idea. A few comments >about your comparison of the SG and Berkeley broadband seismograms:You >compare them on the basis of peak-to-peak counts. I suggest that the >comparison would be more meaningful if it was in terms of actual >velocities, e. g., nanometers/sec. This is what I did in my write-up on >the meter-movement calibrator for the Lehman. The biggest problem with my test was I didn't know how much the table was moving. Since I was interested in freq. I didn't think it mattered, and, I don't have the equipment to accurately measure the small movement. For the Berkeley seismometer I have the following response information: # # ======== CHANNEL RESPONSE DATA ======== B050F03 Station: BKS B050F16 Network: BK B052F04 Channel: BHN B052F22 Start date: 1993,348,00:00 B052F23 End date: No Ending Time # ======================================= # + +--------------------------------------------+ + # + | Response (Poles & Zeros), BKS ch BHN | + # + +--------------------------------------------+ + # B053F03 Transfer function type: A [Laplace Transform (Rad/sec)] B053F04 Stage sequence number: 1 B053F05 Response in units lookup: M/S - Velocity in Meters Per Second B053F06 Response out units lookup: V - Volts B053F07 A0 normalization factor: 987.14 B053F08 Normalization frequency: 0.02 B053F09 Number of zeroes: 2 B053F14 Number of poles: 4 # Complex zeroes: # i real imag real_error imag_error B053F10-13 0 0.000000E+00 0.000000E+00 0.000000E+00 0.000000E+00 B053F10-13 1 0.000000E+00 0.000000E+00 0.000000E+00 0.000000E+00 # Complex poles: # i real imag real_error imag_error B053F15-18 0 -1.234120E-02 1.234150E-02 0.000000E+00 0.000000E+00 B053F15-18 1 -1.234120E-02 -1.234150E-02 0.000000E+00 0.000000E+00 B053F15-18 2 -1.958780E+01 2.456170E+01 0.000000E+00 0.000000E+00 B053F15-18 3 -1.958780E+01 -2.456170E+01 0.000000E+00 0.000000E+00 # # + +-------------------------------------------+ + # + | Response (Coefficients), BKS ch BHN | + # + +-------------------------------------------+ + # B054F03 Transfer function type: D B054F04 Stage sequence number: 2 B054F05 Response in units lookup: V - Volts B054F06 Response out units lookup: COUNTS - Digital Counts B054F07 Number of numerators: 51 B054F10 Number of denominators: 0 # Numerator coefficients: # i, coefficient, error B054F08-09 0 -3.777910E-08 -7.555820E-10 B054F08-09 1 -4.148830E-07 -8.297660E-09 B054F08-09 2 9.445450E-06 1.889090E-07 B054F08-09 3 3.370620E-05 6.741250E-07 B054F08-09 4 -2.429500E-05 -4.859010E-07 B054F08-09 5 1.960520E-05 3.921050E-07 B054F08-09 6 1.544480E-06 3.088960E-08 B054F08-09 7 -2.150600E-05 -4.301210E-07 B054F08-09 8 2.705530E-05 5.411070E-07 B054F08-09 9 -1.676900E-05 -3.353810E-07 B054F08-09 10 5.124170E-03 1.024830E-04 B054F08-09 11 1.779800E-03 3.559600E-05 B054F08-09 12 -4.332210E-03 -8.664430E-05 B054F08-09 13 7.430310E-03 1.486060E-04 B054F08-09 14 -1.039340E-02 -2.078670E-04 B054F08-09 15 1.183280E-02 2.366560E-04 B054F08-09 16 -1.055880E-02 -2.111760E-04 B054F08-09 17 6.859030E-03 1.371810E-04 B054F08-09 18 1.163370E-02 2.326740E-04 B054F08-09 19 -2.604490E-02 -5.208970E-04 B054F08-09 20 4.648550E-02 9.297090E-04 B054F08-09 21 -7.015840E-02 -1.403170E-03 B054F08-09 22 9.522160E-02 1.904430E-03 B054F08-09 23 -1.275080E-01 -2.550170E-03 B054F08-09 24 1.436970E-01 2.873940E-03 B054F08-09 25 8.778300E-01 1.755660E-02 B054F08-09 26 8.819290E-02 1.763860E-03 B054F08-09 27 -1.059150E-01 -2.118300E-03 B054F08-09 28 8.731180E-02 1.746240E-03 B054F08-09 29 -6.899650E-02 -1.379930E-03 B054F08-09 30 4.899210E-02 9.798410E-04 B054F08-09 31 -3.020580E-02 -6.041160E-04 B054F08-09 32 1.640370E-02 3.280730E-04 B054F08-09 33 2.733980E-03 5.467960E-05 B054F08-09 34 -7.899160E-03 -1.579830E-04 B054F08-09 35 1.036420E-02 2.072840E-04 B054F08-09 36 -9.902790E-03 -1.980560E-04 B054F08-09 37 7.607170E-03 1.521430E-04 B054F08-09 38 -4.881500E-03 -9.763010E-05 B054F08-09 39 2.557260E-03 5.114520E-05 B054F08-09 40 4.751230E-03 9.502450E-05 B054F08-09 41 -8.744070E-05 -1.748810E-06 B054F08-09 42 3.545030E-05 7.090060E-07 B054F08-09 43 -3.244920E-05 -6.489850E-07 B054F08-09 44 9.078710E-06 1.815740E-07 B054F08-09 45 1.395880E-05 2.791750E-07 B054F08-09 46 -2.044260E-05 -4.088520E-07 B054F08-09 47 3.442010E-05 6.884020E-07 B054F08-09 48 7.743230E-06 1.548650E-07 B054F08-09 49 -3.925280E-07 -7.850560E-09 B054F08-09 50 -2.914360E-08 -5.828710E-10 # # + +---------------------------------------+ + # + | Channel Sensitivity, BKS ch BHN | + # + +---------------------------------------+ + # B058F03 Stage sequence number: 0 B058F04 Sensitivity: 1.047200E+09 B058F05 Frequency of sensitivity: 2.000000E-02 HZ B058F06 Number of calibrations: 0 # Unfortunately I have no idea on how to read this... If someone does, please let me know. -Larry _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Karl Cunningham <karlc@.......> Subject: Re: Reply Date: Sun, 28 Sep 1997 20:34:06 -0700 Stephen -- You could try downloading event files from the PSN web site at: http://psn.quake.net/cgi-dos/event.exe The page is available whenever the urge strikes you to look at event files, and you wont get any at other times. Just a thought. Karl Cunningham La Mesa, CA. PSN Station #40 karlc@....... At 12:47 PM 9/28/97 -0700, you wrote: >My suggestion would be, as I really would love to have a copy of Winquake >and d/l those event files and learn from them, is that if it was packaged as >a newsgroup, I could d/l my mail when I'm in a hurry, and then choose at my >leisure to get the big stuff. That would solve the problem for me. I don't >know if that's feasible or desireable to anyone else, but it sure would fix >my problem. Karl Cunningham La Mesa, CA. PSN Station #40 karlc@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Al Allworth <aallworth@........> Subject: Re: Reply Date: Sun, 28 Sep 1997 21:10:44 -0700 (PDT) At 03:15 AM 9/28/97 -0700, you wrote: <<Clip>> >regretfully, since there is apparently no more room for a slightly more >casual >reader, then by all means, remove me. > >Thank you, > >-- >Stephen Paul Stephen, I am a little comfused about your complaints. Are you subscribed to more than one list?? I have been on this list for around 2 years years and also another list (not seismic in nature) and have never received any files like you describe. I typically download both list postings in less than a minute - - NO LARGE FILES> ____________________________________________________________________________ Al Allworth, Gold Beach, OR aallworth@........ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Stephen Paul <spaul@............> Subject: Re: Reply Date: Mon, 29 Sep 1997 02:20:25 -0700 Karl Cunningham wrote: > Stephen -- > > You could try downloading event files from the PSN web site at: > > http://psn.quake.net/cgi-dos/event.exe > > The page is available whenever the urge strikes you to look at event files, > and you wont get any at other times. > > Just a thought. > > Karl Cunningham > La Mesa, CA. > PSN Station #40 > karlc@....... > > At 12:47 PM 9/28/97 -0700, you wrote: > >My suggestion would be, as I really would love to have a copy of Winquake > >and d/l those event files and learn from them, is that if it was packaged as > >a newsgroup, I could d/l my mail when I'm in a hurry, and then choose at my > >leisure to get the big stuff. That would solve the problem for me. I don't > >know if that's feasible or desireable to anyone else, but it sure would fix > >my problem. > > Karl Cunningham > La Mesa, CA. > PSN Station #40 > karlc@....... > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L Good idea Karl, I'll try that. Thanks. Didn't know I could. -- Stephen :^) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Stephen Paul <spaul@............> Subject: Re: Reply Date: Mon, 29 Sep 1997 02:21:35 -0700 Al Allworth wrote: > At 03:15 AM 9/28/97 -0700, you wrote: > <<Clip>> > >regretfully, since there is apparently no more room for a slightly more > >casual > >reader, then by all means, remove me. > > > >Thank you, > > > >-- > >Stephen Paul > > Stephen, > I am a little comfused about your complaints. Are you subscribed to more > than one list?? I have been on this list for around 2 years years and also > another list > (not seismic in nature) and have never received any files like you describe. > I typically download both list postings in less than a minute - - NO LARGE > FILES> > ____________________________________________________________________________ > > Al Allworth, Gold Beach, OR aallworth@........ > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L Oh, they were there alright. I don't think anyone disputed >that!<g>... -- Stephen :^) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Norman Davis WB6SHI <normd@.............> Subject: Decoding with sound card. Date: Mon, 29 Sep 1997 07:12:07 I was wondering if anyone Thought of decoding the tones from the remote SN with a sound card. It has been a while since I have done any programing but if someone points me in the right direction I would be willing to give it a stabe. I know this is kind of the horses out of the barn thing as they are going digital but I work for the government and it goes as fast as my end does it may be years before they get it done. Norman Davis WB6SHI Email normd@............. Shingle Springs, Ca, USA it ain't local... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "James M Hannon"<jmhannon@........................> Subject: Re: Decoding with sound card. Date: Mon, 29 Sep 1997 10:16:04 -0500 Norman, It is certanly possible. I have seen a number of programs for receiving RTTY, FAX ,SSTV and Morse code using a sound card. I can't tell you right now exactly where but if you dig in the ham software collections you maybe even able to find some source code. As I remember the sensors FM modulate an audio subcarrier with the information. This is very similar to the FAX or SSTV modulation without the sync pulses. Jim Hannon WB0TXL normd@............. on 09/29/97 02:12:07 AM Please respond to psn-l@............. To: psn-l@............. cc: (bcc: James M Hannon/CedarRapids/Collins/Rockwell) Subject: Decoding with sound card. I was wondering if anyone Thought of decoding the tones from the remote SN with a sound card. It has been a while since I have done any programing but if someone points me in the right direction I would be willing to give it a stabe. I know this is kind of the horses out of the barn thing as they are going digital but I work for the government and it goes as fast as my end does it may be years before they get it done. Norman Davis WB6SHI Email normd@............. Shingle Springs, Ca, USA it ain't local... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: barry lotz <gbl@.......> Subject: Re: Decoding with sound card. Date: Mon, 29 Sep 1997 07:02:19 -0700 Norman I don't know but am interested. Would it be thru the mic input? I think it may be 16 bit but I'm not up on sound card techonology. Barry Norman Davis WB6SHI wrote: > > I was wondering if anyone Thought of decoding the tones from the remote SN > with a sound card. It has been a while since I have done any programing but > if someone points me in the right direction I would be willing to give it a > stabe. I know this is kind of the horses out of the barn thing as they are > going digital but I work for the government and it goes as fast as my end > does it may be years before they get it done. > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Norman Davis WB6SHI <normd@.............> Subject: Re: Decoding with sound card. Date: Mon, 29 Sep 1997 19:52:05 At 07:02 AM 9/29/97 -0700, you wrote: >Norman > I don't know but am interested. Would it be thru the mic input? I >think it may be 16 bit but I'm not up on sound card techonology. Yep but as soon as I went out to look at the signal I found it was gone. So much for that. Norman Davis WB6SHI Email normd@............. Shingle Springs, Ca, USA it ain't local... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson <dann@........> Subject: Re: Decoding with sound card. Date: Tue, 30 Sep 1997 16:20:12 +1200 the problem with sound card and assoc. software logging is that the sample rate is extremely high (1k sps +++) and cannot be lowered to a very low rate for seismic work. As a result the length of sampling time is very short less that a minute or so (rate and ram space dependant) and it produces very large sized files Dave At 07:52 PM 9/29/97, you wrote: >At 07:02 AM 9/29/97 -0700, you wrote: >>Norman >> I don't know but am interested. Would it be thru the mic input? I >>think it may be 16 bit but I'm not up on sound card techonology. > > > Yep but as soon as I went out to look at the signal I found it was gone. > So much for that. > > >Norman Davis WB6SHI >Email normd@............. > > >Shingle Springs, Ca, USA it ain't local... > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > Co-ordinator: New Zealand Public Seismic Network Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Al Allworth <aallworth@........> Subject: Re: Reply Date: Mon, 29 Sep 1997 21:30:19 -0700 (PDT) At 02:21 AM 9/29/97 -0700, you wrote: > >Oh, they were there alright. I don't think anyone disputed >that!<g>... >-- >Stephen :^) > I certainly don't understand this one. I have never received any large files from PSN. I do occasionally on the other list and on a NASA list I'm on, I only get large files but only once every week or so. I guess I must be having good luck or something. ____________________________________________________________________________ Al Allworth, Gold Beach, OR aallworth@........ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Pete <alarm@...........> Subject: Re: Decoding with sound card. Date: Mon, 29 Sep 1997 22:35:06 -0700 David A Nelson wrote: > > the problem with sound card and assoc. software logging is that the sample > rate is extremely high (1k sps +++) and cannot be lowered to a very low > rate for seismic work. > As a result the length of sampling time is very short less that a minute > or so (rate and ram space dependant) and it produces very large sized files > > Dave > > At 07:52 PM 9/29/97, you wrote: > >At 07:02 AM 9/29/97 -0700, you wrote: > >>Norman > >> I don't know but am interested. Would it be thru the mic input? I > >>think it may be 16 bit but I'm not up on sound card techonology. > > > > > > Yep but as soon as I went out to look at the signal I found it was gone. > > So much for that. > > > > > >Norman Davis WB6SHI > >Email normd@............. > > > > > >Shingle Springs, Ca, USA it ain't local... > > > >_____________________________________________________________________ > > > >Public Seismic Network Mailing List (PSN-L) > > > >To leave this list email listserver@............. with the body of the > >message: leave PSN-L > > > > > > Co-ordinator: > New Zealand > Public Seismic Network > Dave A. Nelson > 24 Jensen St., > Green Is., Dunedin, > South Is.. New Zealand. > > http://psn.quake.net/dave/home.htm > > IF there indeed are other parallel universes... I can now rest in the > knowledge, that in at least one of them, I am filthy rich and drive a red > Ferrari > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L I was thinking about making an earthquake alarm using the remote SN. I plan to use a frequency to voltage converter and set the alarm to trigger when there is a pre-set voltage difference. Does anyone have any thoughts on this? If distant enough, it may be used as a warning! Thanks, Peter Fleming alarm@........... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane <cochrane@..............> Subject: New NewFile mailing list & summary of mailing lists Date: Mon, 29 Sep 1997 21:45:12 -0700 Greetings, There has been some discussions about the NewEvent mailing list and the sending of large attachments to the members of that list. There is nothing I can do about that because that is what is exactly what it is meant to do. So that people can be notified of new event files sent to event@.............. but without the attached file(s) themselves, I have created a new mailing list called NewFile. It is similar to the NewEvent list except you will not get the attached file(s). What you get is something like this: Date: Mon, 29 Sep 1997 19:45:46 Pacific Daylight Time From: event@............. Subject: New event files To: cochrane@.............. X-Mailer: <WinNT's Blat ver 1.2> Submitted By: pgianni@......... ----------------------------------------------------------- The following event files have been uploaded to the PSN Archive System: ftp:\\psn.quake.net\quakes\9709\970930a.cmb ftp:\\psn.quake.net\quakes\9709\970930a.sfz ftp:\\psn.quake.net\quakes\9709\970930a.sfn ftp:\\psn.quake.net\quakes\9709\970930b.cmb The original message, sent in by Phil Gianni, did not contain a subject or any text. If he had, the subject line would be appended to the "Subject: New event files" line and the text part of the message would show up between Submitted By: line and the line of "-------". If you submit event files please add a subject line (maybe the location?) and any special information, in the text part of the message, about the event or equipment etc... Unfortunately my archive system will loose the subject and text info, but I expect a lot of people will join the NewFile list now that the message does not contain the attached event files. So any info about the event file will be helpful. If you would like to subscribe to the NewFile list you can use the following Web page form at http://psn.quake.net/maillist.html. You can also send an email message to: listserv@............. or listserv@.............. In the body of the message (not the subject line) place on the first line: subscribe NewFile Here is a summary of the mailing lists I currently have: ------------------------------------- PSN-L@............. or PSN-L@............... Note: you do not need to use the cap letters PSN-L. I do it because people sometimes us a 1 (one) for the L. This list. It is used of the general discussions of making and running of seismometers etc... Please DO NOT send attachments over a few 1000 bytes to this list. Commands (subscribe, unsubscribe etc) for this list should be sent to: listserv@............. ----------------------------------- NewFile@............. or NewFile@............... This is the new list I just created. It is used to notify the list members of new event files sent to event@............. (or event@............... but without the attached event(s). Since this list is for notification of new event files sent to my system, there is no reason to post messages to this list directly. Commands for this list should be sent to: listserv@............. ----------------------------------- The following two list reside on another system, drnet.com, that I have access too. I do not own this system so I have little control over it. It is connected to a T1 so I like using it for the list below because of the larger bandwidth needed to send out the attachments. I don't want to move the PSN-L and the new NewFile list over too it because I could lose access to it at any time. If that where to happen I would then drop the NewEvent list and move the SDRUSER list over to the psn.quake.net (or webtronics.com is the same computer) but not send out attachments. ------------------------------------- NewEvent@.......... This list is like the NewFile list above but it also contains the attached event file(s) that where sent to the event@.... email address. Since this list is for notification of new event files sent to my system there is no reason to post messages to this list directly. Commands should be sent to listserv@......... or NewEvent-request@.......... ------------------------------------- SDRUSER@.......... I use this list to send out new release of my SDR (Seismic Data Recorder) software program that works with my 12/16 bit A/D card or a 12 bit PC-Labs 711s (or compatible) A/D card. It can also be used as a general discussion forum related to the software/hardware. Commands should be sent to sdruser-request@.......... Hope this helps. -Larry Cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson <dann@........> Subject: Re: Decoding with sound card. Date: Wed, 01 Oct 1997 00:06:46 +1200 Peter, Larry's SDR data logging system already has a built in alarm system and can be set to any chosen input level it works very well as a lot of us on this mail list will testify. It has dragged me out of bed often in the middle of the nite to witness a big event coming in, or even when I'm sitting at the computer on the net etc.... the alarm will suddenly go off on the digital seismograph behind me. Dave > >I was thinking about making an earthquake alarm using the remote SN. >I plan to use a frequency to voltage converter and set the alarm to >trigger when there is a pre-set voltage difference. Does anyone have any >thoughts on this? If distant enough, it may be used as a warning! > >Thanks, >Peter Fleming >alarm@........... > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > Co-ordinator: New Zealand Public Seismic Network Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm IF there indeed are other parallel universes... I can now rest in the knowledge, that in at least one of them, I am filthy rich and drive a red Ferrari _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Phil Giannini" <phil_giannini@...........> Subject: Decoding Date: 30 Sep 1997 09:23:48 -0800 REGARDING Decoding Hi To Everyone, All this discussion about decoding through a sound card sparks a question for me as well. Some time back I found a location on the internet where there was a recording of the Landers quake sped up many times so you could hear the sound of the quake. It was quite interesting and kind of fun. The file was in ..AU format therefore readable with a sound card and sound software. My question is, does anybody know if there is a way to take a PSN file recorded on SDR and turn it into a file that can be read by a sound card in the same manner as the Landers quake was. As a side note, I have been using one of Larry's demodulator cards for some time now, and works like gang busters. I built it into a portable recording unit that I brought along on my vacation to Mammoth, and to a remote location near the geysers. Each site had a different telemetery tone frequency and the unit locked up every time to the different tones. It just sat there and worked in some pretty hostile conditions like high ambient temperatures and battery power which changed as the batteries depleated. If telemetery recording is what you want to do, I can certainly recommend Larry's card. I plan to post a little summary and some pictures of my remote recording unit in the near future. Thanks for any input and for listening. Regards, Phil SFN & SFZ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: mbruenje@........ (Fred Bruenjes) Subject: Re: Decoding Date: Tue, 30 Sep 1997 10:26:49 -0700 >My >question is, does anybody know if there is a way to take a PSN file recorded >on SDR and turn it into a file that can be read by a sound card in the same >manner as the Landers quake was. I did this for the Nazca, Peru 7.3 quake of November 12, 1996 and put the results on my website (http://ieng9.ucsd.edu/~mbruenje/seismo/quakes.html). It's a really funky sound - kind of like a "KERwhunk". I couldn't find a program anywhere that could do the conversion for me, so I had to do it myself, in two steps: First, I wrote a little C program to load the PSN file, scale the data from 12 bits down to 8 bits, and save it as raw data (no header info). Then I opened the raw file in WHAM (Waveform Hold and Modify, a shareware audio editor), selected the playback rate, and saved it to WAV and AU versions. If I had the file specifications for the WAV or AU formats the C program could have gone straight from the PSN file to an audio file. So, there is a way to do the conversion, but it is not for the faint of heart. It would be a neat feature to add this capability to WinQuake - some sort of a radio button or checkbox on the file save screen to select PSN or audio file format. Fred -------------------------------- Fred Bruenjes mbruenje@........ http://ieng9.ucsd.edu/~mbruenje/ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L)