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Nininger Moment #12
A Classification of the Meteoritic Additions to the Earth
It is evident that the materials composing a meteorite are widely
distributive during the process of its fall to Earth. Some of the
material is reduced to the finest powder and probably a considerable
portion is transformed into gases. Certainly some of this
disintegration begins in some cases, as high up as one hundred miles
above sea level and apparently continues within a few miles of the
soil. The distribution of the surviving fragments may be considered
both from the standpoint of the area over which they are scattered,
and from a standpoint of the depths to which they penetrate the
ground. So far as is known to this writer, no attempt has been made
to deal systematically with the penetrative distribution of
meteorites. It is only fair to state that in this writers opinion,
our knowledge in this field is too meager for any attempt at final
conclusion.
A study of 102 witnessed falls reveals the fact that from these
falls 50 individuals were recovered from below plough depth. The
average weight of these 50 stones and irons were 84..7 lbs. (38.5
kilos) The average depth buried was 22 inches (55 cm) Thirty two of
the fifty had weights of less than 50 lbs (22.7 kg) and an average
weight for these were 20.3 lbs. (9.2kg) The average depth of burial
for these 32 were 20.3 inches (50.8 cm)
Six individuals weighed between 50 lbs and 100 lbs (22.7 and 45.4
kg) with and average weight of 63 lbs. (28.6 kg) for these the
average depth of burial was 32 inches or (80 cm) Seven individuals
weighed between 100 lbs and 200 lbs. or (45.4 kg and 90.8 kg) with
and average weight of 139 lbs (63.2 kg) for these the average depth
of burial was 43 inches or ( 107.5 cm) Two individuals weighed
between 200 and 400 lbs. (90.8 and 181.6 kg) and the average weight
for these was 230 lbs. (104.5 kg) and the average depth of burial
was 48 inches (120 cm) Three individuals weighed more than 400 lbs
(181.6 kg) each; and these were buried at an average depth of 122
inches (305 cm)
Generally speaking it may be said that the depth of burial increases
with the diameter of the meteorite, though of course there are
several factors which greatly modify this relationship. The shape
and specific gravity, the angle and velocity at which it falls, and
the nature of the soil (soft/hard etc.) As far as we know the
majority of stony meteorites of less than 300 grams do not bury
themselves completely in the soil. Many stones as massive as one
kilogram (2.2 lbs) have been found freshly fallen on the surface of
the soil and in some cases as heavy as five or six kilograms (11 to
13.2 lbs) have come to rest on ordinary soil without sinking into it
even half their own diameter. Irons have buried themselves usually
about 50 percent deeper than stones. In a few rare instances as in
the Lumpkin stone weighing 12.5 Oz (354 g) buried itself rather
deeply in hard ground at a depth of 10
inches (25 cm)
Source: The Published Papers Of H.H. Nininger
By the Center for Meteorite Studies Arizona State University, Tempe,
AZ
Published originally in Popular Astronomy 1935
The Nininger Moments are articles or books written originally by
Harvey Nininger and put into a consolidated form by Al Mitterling.
Some of the items written in the moments might be old out dated
material and the reader is advised to keep this in mind.
--AL Mitterling
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