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vaporized cloud matter fron the surface of the earth. The radtonucleides
produeed by the explosion say be deposited on or incorporated inte thia
material depending upon whether or not it 1a more or less caspletely
fueed or totally vaporised.
After the fireball covls, the larger particles
daposit on the earth in a matter of mimtes and up to several hours after
the detonstion.
This senstitutes the legal or neamin or early fallout
weich for mall weapons may extend out from the pcint of burst a few
miles and cover tens to a few hundreds of square miles while for mageton
weapons 1% may extend out to a sevexvea) hundred ar nore miles and cover
thousands of oquary ulles,
‘tropospheric or latitudinal fallout is a more delayed fallout of
the debrie which either has not penetrated the trepepause te the stratcaphere or if it hae penetrated into the lower stratosphere tha particle
ize is euch that it cases down fairly rapidly.
It occurs over a period
of tw or three weks or a month or so after a detonation and consists
ef relatively fine material (a few micra to small fractions of a micron)
suspended in the lower part of the atmosphere, the troposphere, where
rain and other weather phencasna occur.
It is carried around the world
in the same general band of latitude as that of its origin and dees not
in any significant amount cross the equater.
It is deposited on the
earth's surface by weather events, principally rain and snow and probably
to soma axtont by dew. Thus, the distribution of tropospheric fallout
is determined cemrally by the site of foamation, factors such as local
weather conditions and distance traveled (in thousands of miles)
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