[meteorite-list] Whats the average Strewn Field size for meteoritefall and could size predict Strewn Field size?

From: Matson, Robert D. <ROBERT.D.MATSON_at_meteoritecentral.com>
Date: Wed, 31 Mar 2010 14:32:33 -0700
Message-ID: <7C640E28081AEE4B952F008D1E913F1703128D72_at_0461-its-exmb04.us.saic.com>

Hi Shawn,

Years ago, I remember reading that the median number of stones produced in
a witnessed fall is 5. (The average is certainly much more than this since
some falls have produced thousands of meteorites, and there have only been
about 1100 falls.)

The size (i.e. length) of any strewn field is most directly related to
the entry angle of the original meteoroid, and the local wind velocity
profile at the fall location. For steep entry angles, local wind speed
may be the dominant factor in strewn field length and orientation (as
will be the case with the Lorton fall if a second stone is found).

The total number of stones produced in any fall will be quite unpredictable
since it critically depends on several unknown factors: bulk porosity of
the meteoroid, its initial shape and mass, etc. Often we don't even know
the entry angle or entry velocity of a fall, both of which influence the
amount of fragmentation.

If you have only one meteorite sample from which to draw conclusions
about the possible total number of meteorites in a fall, mass is probably
not a very good indicator. Better indicators might be friability or the
presence of a secondary fusion crust.

Cheers,
Rob

-----Original Message-----
From: meteorite-list-bounces at meteoritecentral.com [mailto:meteorite-list-bounces at meteoritecentral.com] On Behalf Of Shawn Alan
Sent: Wednesday, March 31, 2010 2:00 PM
To: meteorite-list at meteoritecentral.com
Subject: [meteorite-list] Whats the average Strewn Field size for meteoritefall and could size predict Strewn Field size?

Hello Listers
?
I have a good question about the average size of a Strewn Fields. A good example would be the Ash Creek fall in 2009. Whats the size of that Strewn Field and the collected amount of?weight so far from that fall? Why I ask is because?there could be a pattern with size of meteorites, the amount of meteorites recovered, or the lack there of, and?one might be able to predict the size of the Strewn Field even if?there is only one or two meteorite pieces recovered. This average could be applied to the Lorton Fall a few months ago in Virgina, which to this date only one individual pieces has been recovered at 318g. One could suggest?that?this piece could be the main?mass and calculate the mean average of the suggested?strewn field that could result from this weight. By doing this?and also cross?referencing with other falls that have?a?mean average weight from the main mass and?TKW recovered could this?predict the average size of the strewn field as long as the class of the meteorites falls are?in the same category
?
?
Shawn Alan
Received on Wed 31 Mar 2010 05:32:33 PM PDT