[meteorite-list] Seismic Data search for 6JUL09 meteor

[Chris Peterson]

Impacts don't create seismic events (unless they are hypervelocity, in which 
case they are easily located by the resulting crater!). The seismic events 
sometimes recorded are produced by atmospheric shock waves created by the 
fireball. And like video records, they only help establish a location for a 
segment of the path, and not the final position of any strewn field (which 
can be substantially in front of, behind, or to the side of the terminal 
explosion location).

Chris

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Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com


----- Original Message ----- 
From: "Kelly Beatty" <jkellybeatty at comcast.net>
To: <meteorite-list at meteoritecentral.com>
Sent: Thursday, July 09, 2009 12:08 PM
Subject: Re: [meteorite-list] Seismic Data search for 6JUL09 meteor


folks...

my take: this putative fall is unlikely to generate a seismic signal if
pieces hit the ground at terminal free-fall velocity (several hundred mph
for really large chunks, much less for smaller ones).

meanwhile, I've analyzed Mike Hankey's photo. assuming the bolide was 1:10
am local time and "falling from the sky", as reports indicate, then the
meteor segment in the image he took was centered at AZ 73°, AL 63½°, and had
a bearing toward the east-northeast horizon.


clear skies,
Kelly

****************
J. Kelly Beatty
Senior Contributing Editor
SKY & TELESCOPE
617-416-9991
SkyandTelescope.com