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Chyba, Impacts & Test Ban Treaty

Re: abstract from LPSC on impacts.
The texts I was working with are just two page abstracts, with little
detail provided.

>if an iron meteorite fell causing a 3.6 shock, wouldn't it be
>possible to use the recordings of three seismic stations, and triangulate
>the information to find the crater?

I don't know, but there is a lot of activity at that low seismic level,
little or none of which is studied.  I think that was the author's point
when he said, "The existing seismic records probably include meteorite
impacts misidentified as earthquakes." 
I believe that location is possible with limited accuracy, but very
complicated by propagation through faults, echo off boundaries, etc.

>It is also my understanding that two measures are provided by the
>seismographs, the earth-surface location of the movement, and the depth of
>the mechanics causing the movement. Since most earthquakes originate many
>kilometers below the surface, there should be a clear, or at least
>reasonable distinction between an impact seismic fingerprint and that of an
>earthquake.

I imagine that an impact does have a quite different signature than fault
lines in motion, at least when it is initiated.  They might not be as
easily distinguishable after bouncing around inside the earth.
______________________________________
Peter Abrahams, telscope@europa.com