[email protected] said: > Related to that, are there any seismometer experts on the list? I've always > wondered why they don't augment the extremely sensitive detectors with less > sensitive detectors? Of course a really good detector will overload; so just > co-locate cheap detectors that are 40 and 80 dB less sensitive. That way you > get a clean signal no matter how close or far the epicenter is from the > detector.
I'm not a seismometer expert, but I live/worked close to the USGS Menlo Park campus. A couple days after the 1989 Loma Prieta earthquake, I wandered over there to see if there was anything interesting for people like me to see. I was in a glass enclosed walkway between two buildings. They had a long (20 ft?) seismograph printout taped up high on one side. The first foot or two had obviously saturated. There was a guy next to me who looked like he might know something, so I asked, roughly, "Don't they have stations with the amplification turned down so it doesn't saturate?" He gave me a dirty look and said "That was the low gain channel." I think there are two issues with saturation. One is the electronics and communication channel. The other is the instrument itself. There is probably a seismic-nuts list someplace. There is a lot of good work going on in that area. My favorite seismic URL is: The Yosemite Rock Fall of July 10, 1996 UC Berkeley Seismographic Station, Earthquake of the Week http://seismo.berkeley.edu/seismo/events_of_interest/yosemite/eoi_yos.html For only slightly-geeky amateur seismology, try QCN Quake-Catcher Network http://qcn.stanford.edu/ For $50 you can get a USB connected seismometer. They provide software that will plug it into their data collection setup. Here is a good note: http://qcn.stanford.edu/qcn-detects-earthquake-in-seconds Some/many modern fancy cell phones include accelerometers. There is at least one app that turns your phone into a seismometer and displays a graph. -- These are my opinions, not necessarily my employer's. I hate spam. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
