Dave, You are way out of line and very mis-informed in stating that seismologists are "rich". Over three decades I have seen amazing self sacrifice and personal investment on the part of seismologists to achieve the data quality that is required. The current new generation of broadband instruments are so expensive that often the qualified technical personnel to install and operate them have to be left out of the budget, and volunteers have to try to do the work. The only people who had adequate funding was the AFOSR (Air Force Office of Scientific Research) during the cold war for installing seismic systems for nuclear test detection. Even the current CBTB (comprehensive test ban treaty) verification instrumentation funding is very limited. But for the most part, most seismologists have to do most of the work of preparing sites and installing instruments themselves because they cannot afford commercial contractors. And after a site is established, the continuing operation is up to the scientists' dedication, like paying the postage to mail data tapes. We "rich seismologists" of course have never "dreamed of" such poor sites as a carpeted floor, because in the past 50 years someone has tried it and found the idea to be a dud compared with what their colleagues were getting from more carefully prepared (and probably more difficult) sites. Even in the 20's era of mechanical-optical- photo-recording instruments of quite low sensitivity, the quietness and isolation of a pier in a vault was desired. Our old SLM vault at St. Louis U. was installed deep under the lobby of a new gym in 1923 when a Jesuit (Fr. Macelwane) found bedrock there and twisted other Jesuit arms to get it installed for free. As for the site of a long period instrument, particularly a horizontal, I would encourage everyone to make every effort to optimize the site conditions. I don't think "easy" or "convenient" are valid criteria if you want to record more than a few large quakes per year, like todays Ms 7.2 in the Philippines, which should have been very well recorded by all the PSN instruments. The monthly-or-so M 6.0 events will be about 6% of this amplitude, and should also be clearly recorded just to keep up interest (= maintenance/adjustment). I routinely run preliminary tests of instruments in my lab on the third floor of a very sturdy building (it was designed for 8 floors that never got built because the Univ ran out of $$). Even adjacent to a 30" square pillar, my lab floor runs at about a continuous Ms 3.0 quake. The whole building tilts several micro-radians daily as the sun warms the south side. Even the test pier in the basement is swamped with the noise of the AC fans, the elevators, the streets, etc. My only "good" test site is 40 km away in a WWII munitions bunker, (black powder on the floor) but I still see the noise of the interstate about 0.5 km away. Regards, Sean-Thomas __________________________________________________________ Public Seismic Network Mailing List (PSN-L)
Larry Cochrane <cochrane@..............>