[meteorite-list] Statistically Speaking
From: Paul H. <oxytropidoceras_at_meteoritecentral.com>
Date: Sun, 20 Nov 2011 8:34:56 -0600 Message-ID: <20111120093456.GWHMX.66796.imail_at_eastrmwml105> 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. Received on Sun 20 Nov 2011 09:34:56 AM PST |
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