Including Original "Paul H. Letters" Copyright © 1996-2017 Paul V. Heinrich - All rights reserved.



Sunday, 20 November 2011

Statistically Speaking

Statistically Speaking


In "Statistically Speaking" at
http://six.pairlist.net/pipermail/meteorite-list/2011-November/081289.html
Ruben asked:

6. Q. How much in weight does the earth gain per year 
by all the meteorites that enter our atmosphere? Including 
all, from tiny grain of sand meteorites to large bunker-
busters.

Below is what I could find with a limited search.

1. Bland (2001) states:

"This, together with the number and mass distribution 
of paired meteorites in each region allows an estimate of 
the number of meteorite falls over a given mass per year: 
between 36 and 116 falls over 10 g per 1,000,000 km2/yr. 
In addition, the total mass flux to the Earth 's surface over 
the 10 g -1 kg interval is constrained to between 2900 and 
7300 kg/yr."

and

"These and other estimates of flux for cosmic dust yield 
a reasonably consistent estimate of 30-40 Gg per year."

Halliday (2001) states:

"About 4500 events per year appear to deposit at least 
a kilogram of meteorites somewhere on Earth, including 
those that land in oceans."

3. Hughes (1991) states:

"Unfortunately the only conclusion that can be drawn 
from this review is that the meteorite flux to the Earth's 
surface is still a quantity that is imperfectly known. The
parents of meteorites have masses in the range between 
1,000 and 1,000,000,000 g. The annual flux to the top of 
the atmosphere in this range is 12,400,000,000 g and 
this is made up of 870,000 individual bodies."

There is:

Meteorite Flux - Part 1 of 6
http://www7.pair.com/arthur/meteor/archive/archive9/Dec99/msg01031.html

Meteorite Flux - Part 2 of 6
http://www7.pair.com/arthur/meteor/archive/archive9/Dec99/msg01032.html

Meteorite Flux - Part 3 of 6
http://www7.pair.com/arthur/meteor/archive/archive9/Dec99/msg01033.html

Meteorite Flux - Part 4 of 6
http://www7.pair.com/arthur/meteor/archive/archive9/Dec99/msg01034.html

Meteorite Flux - Part 5 of 6
http://www7.pair.com/arthur/meteor/archive/archive9/Dec99/msg01036.html

Meteorite Flux - Part 6 of 6
http://www7.pair.com/arthur/meteor/archive/archive9/Dec99/msg01035.html

Part 6 has the type of statistic that newspaper and TV 
reporters seemingly love to throw into an piece.

"So each 18-hole golf course has about a 1 in 100,000 
chance of being hit by a meteorite every year."

References Cited:

Bland, P. A., 2001, Quantification of Meteorite Infall Rates 
from Accumulations in Deserts, and Meteorite Accumulations 
on Mars. in B, Peucker-Ehrenbrink and B. Schmitz, eds., 
pp. 267-304. Accretion of extraterrestrial matter throughout 
Earth's history. Kluwer Academic/Plenum Publishers, New 
York, New York.,

Halliday, I., 2001, The Present-day Flux of Meteorites to the 
Earth in B, Peucker-Ehrenbrink and B. Schmitz, eds., 
pp. 305-318. Accretion of extraterrestrial matter throughout 
Earth's history. Kluwer Academic/Plenum Publishers, New 
York, New York.,

Hughes, D. W., 1991, Meteroite flux. Space Science Reviews.
vol. 61, pp. 275-299,

Yours,


Paul H.

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