[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: Abstracts on impacts from 29th LPSC
Martin, You sent a reply to me instead of Peter?
Thanks
Mike
Martin Horejsi wrote:
> Hello Peter,
>
> Thank you for your posting. I do have a question. In your message, the
> following was mentioned:
>
> "Verification of the comprehensive test ban treaty (forbidding underground
> nuclear bomb tests) includes seismic detectors that could be triggered by a
> meteorite impact. 50 of these detectors, across the globe, can detect
> seismic magnitudes of 3 or 4. This has already been an issue of concern;
> in 1993, a seismic event of mag 3.6 in W. Australia occurred just north of
> ์where members of the Aum Shinrikyo terrorist cult had been trying to mine
> uranium, and carrying out tests with chemical weapons.๎ The conclusion was
> that the seismic event was probably an iron meteorite, creating a crater
> over 100 meters in diameter [no mention of discovery of such a crater].
> Ablation & deceleration in the atmosphere, frequency of iron & stony
> meteorites, water surface of the earth, and other factors were considered.
> It is concluded that meteorite impacts that could trigger the seismic
> detectors occur on a time scale of decades. The existing seismic records
> probably include meteorite impacts misidentified as earthquakes. (Chyba)"
>
> Peter, 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?
>
> 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.
>
> Any thoughts?
>
> Martin
References: