[meteorite-list] Estimating meteorite annual fall rates

From: Matson, Robert <ROBERT.D.MATSON_at_meteoritecentral.com>
Date: Thu Apr 22 09:42:00 2004
Message-ID: <AF564D2B9D91D411B9FE00508BF1C8692C5E58_at_US-Torrance.mail.saic.com>

Hi Kelly and list,

Kelly wrote:

> In my post to the List about calculating the frequency of meteorite
> infall from the data for targets that they strike, I wrote: "The data
> for U.S. automobiles is 250% of expectation, suggesting a flux of 59,825
> meteorites per year..."

> That was based on four hits on U.S. automobiles per century. This
> incident, if verified, would raise that to five hits per century (two of
> them within four years!) or three times the number expected from an
> infall of roughly 24,000 meteorites per year, which implies about 72,000
> meteorites per year actually fall.

> For the decade of the 1990's, taken separately, two hits is more
> than five times the chance expectation for the "official" rate of 24,000
> meteorites per year, which would translate to an equivalent rate of
> 125,000 meteorites per year!

I recently performed an independent analysis and calculation of
global annual fall rates based on southern California meteorite
finds from a number of Meteorite Recovery Foundation (MRF) study
areas. This calculation involved search surface areas, visual
detection range vs. search velocity, total field manhours per
study area, and a variety of assumptions about surface age,
deflation and weathering.

Using the most pessimistic assumptions, the global annual rate
computed to ~160,000 for meteorites 10 grams or larger. The
actual value is probably several times higher than this.

--Rob
Received on Tue 16 Jan 2001 05:52:20 PM PST