UNCLASSIFIED
Further study of the data has led to the conclusion that the
earlier explanation of the phenomenon was incomplete and that the
mnovenent of electrons resulting from large explosions is more com-
plex than originally assumed. Additional experimental data from more
locations will be required in order to complete the picture.
Dek
DISTANT EFFECTS
A disturbance that is propagated in the upper ionesphere for
thousands of miles appears to be initiated by shots of sufficiently
large magnitude. The minimum yield requisite for its initiation is
indicated as probably between 7 and 11 megatons. The velcecity of
propagation is indeterminats but has been within the range of 7.7 to
15.5 km/min to date.