[meteorite-list] Annual fall rate revisited

[Matson, Robert]

Hi Göran, Sterling and List,

Summarizing Sterling's recent detailed post of annual meteorite
fall statistics:

Nininger estimate:    500/year on land (2000/year entire earth)
                      100g - 10kg

Canada MORP:          23930/year (radar detection of fireballs)

Phil Bland '96 study: 18000 - 84000/year
                      (based on find rate vs. weathering rate of
                      find locale)

Sterling Webb study:  59825/year
                      (based on hit rate for houses/ships/cars/trucks)
                      60000-100000/year to account for underreporting
                      and/or undetected or misattributed damage

Matson '03 estimate:  120000-150000/year based on Mojave Desert
                      unpaired field recovery rate of ~1 met/km^2.

There is a lot of uncertainty in my 120k-150k estimate due to the
unknown terrestrial lifetimes of the finds.  It is doubtful that
any of the finds that went into my statistics are older than
15,000 years, and most are quite a bit younger than this.  Of the
50+ unpaired finds making up the statistics, a dozen are W2, and
five are W1.  I doubt any one of these 17 is older than 1000 years,
and a few may be younger than a decade, suggesting that the 120-150k
is conservative.  --Rob