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material into t:.e atmosphere, Although no accurate figures exist, it has
been variously estimated that 13 cubic miles disappeared during Krakatoa,
and from 1 to 5 cubic miles of material were ajected from the Katmai
Volcano in 1912.
Some of these volcanic eruptions lasted over a period
of days or weeks with variations in the intensity of explosions, There is
no doubt that large volcanoes eject much more total mass into the atmosphere
as compared to any man made explosion, since even megaton weapons could not
eject more than a small fraction of one cubic mile of material high into
the atmosphere. However, it may be that volcanoes are not efficient in
this matter, in that they waste a very large amount of their total output
in the lower layers of the atmosphere. It should be noted that to produce
any persistent lowering of the intensity of solar radiation reaching the
surface of the earth, volcanoes must throw out high into the atmosphere
(20 to 30 miles high) fine volcanie ash particles that will not settle
out over a period of several years. Hence a comparison of the total mass
ejected by volcanoes as compared to that ejected by Super-weapons may not
be significant, It is more important to determine the heights reached by
such particles, and if possible, the particle size distribution of the.
dust reaching such heights. There is practically no information concerning
the amount of dust that may be ejected aloft as a result of exploding
superweapons on the surface or underground, According to references (8)
and (8a), the cloud produced by 320,000 lbs, of TNT explosion weighed
approximately 46,000 lbs. and had a yolume of 1 x 10/9 cubic feet.
gives the c..ud density as 4.6 x 107°
lbs/cu.ft.
This
However, when a particles
size analysis was made, it was determined that there were very few if any
particles greater than 3 microns in the cloud sampled and 40% to 70% of
the particles collected were below 0.8 micron in size, This means that
the 46,C00 3, weight refers to the stabilized cloud and it certainly refers
to the weight of very small particles in the cloud,
Actually very little
reliable data exists on the pro “em and the whole method of measuring
particle sizes is dependent upor
and also upon the method of ana.
particle size distribution during
x2e methods used to collect the samples
3. For example, in studying the
>eration Jangle (2) it was found that.
the median particle diameter for gross samples was 0.22 micron when measured
under the electron microscope whose limit of resolution is probably two
orders of magnitude greater than the 0.5 micron resolving power of the
optical microscope, and the median particle diameter of radioactive
samples as measured by the optical microscope was 1.4 microns. Reference
(8) gives the particle concentrations for the cloug
from 1.0, 0.5
0.2 scale TNT shots as 2300 particles/cm?, 6700/cm? and
spectively,
and
2565/em re-
It is assumed from this information that particle concentration
in TNT explosion clouds is a function of the total amount of explosive used
at scaled depths. It should be noted that 1.0 scale refers to 320,000 lbs.
of TNT exploded 35 ft. underground, 0.5 scale refers to 40,000 lbs. TNT
exploded 17 ft. underground and 0,2 scale refers to 2560 lbs, exploded 7 ft.
underground,
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These charges and depths of explosion are scaled so that x
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