Hi Steve, At 06:12 AM 6/7/00 +1000, Steve Olney wrote: >2. I would like to try and build a vertical seismograph using some Aura >shaker transducers I have. I have tested the resonance frequency and they >appear to be around 40Hz. I intend to try and make a vertical force-balance >type which I understand is really an accelerometer. Yes, I believe that is correct. > >Question: What is the relative sensitivities and relative amplitudes of >events of horizontal versus vertical seismographs? What are the relative >pros and cons of vertical versus horizontal seismographs? Is there any >disadvantage in using accelerometer (force-balance?) types versus >displacement or velocity types of seismographs? I like running horizontals, if the sensor is in an area like mine with a lot of local ground noise from car trucks etc. Since most of the energy of the noise is in the vertical direction, a horizontal sensor will not pick up as much signal from cars and trucks going by. You can see the difference by looking at my *.LCZ (vertical), *.LCN (N-S horizontal) and *.LCE (E-W) event files. A good example is a M2.6 event 26km from me that happened last month. The event files are 000530A.LCZ, 000530A.LCN and 000530A.LCE. As you can see the event is hard to see in the vertical direction. The horizontal channels show the event very clearly. The sensor used to record this event is a three channel forced-balanced accelerometer with all channels having the same sensitivity. >3. If I wanted to send a contribution to the supporters of this email >reflector, who, where and how could I send it from here in Australia? Thanks, but given the extra cost to transfer money don't worry about it. Regards, Larry Cochrane Redwood City, PSN __________________________________________________________ Public Seismic Network Mailing List (PSN-L)
Larry Cochrane <cochrane@..............>