example.
During World War I the City of Halifax was
devastated by the explosion of a munitions ship in the
harbor having aboard over 2000 tons of high explosives.
Not only was there enormous property damage but approximately 10,000 people iost their lives or were injured.
This blast, in nuclear weapons terminology, had an energy
equivalent to slightly more than two kiiotons, a very small
explosion in these terms.
The so-called nominal bomb of 20
kilotons releases approximately 10 times the energy of an
Halifax explosion while our largest fission bombs will yield
the energy of 250 such ships all consumed in one gigantic
detonation.
But when we speax of the thermonuclear weapons, a
still larger unit becomes convenient.
This is the mezgaton
or 1000 kilotons of TNT equivalent.
One megaton would thus
be represented by the explosion of a line of such ships bow
to stern extending for <0 miles.
With such a great range of possible energy yields,
how may we relate the effects of one explosion to those of
another of entirely different level of power? The volume
"The Effects of Atomic Weapons," published in 1950, was
written before these very large weapons had been tested.
The yield of 20 kilotons was taken as the basis for the
book and extensive data were given for this so-called
"nominal" bomb.
The existence of yields other than this
was not implied but scaling laws which should serve to
predict the effects from cther yields were included.
Without entering into a discussion of the degree to which these
laws apply to all situations, we may use them with confidence as being sufficiently descriptive for civil defense
needs.
Since we are especiaily interested in blast, thermal
effects, and nuclear iaciaczion, the foilowing equations may
be used to relate these quantities for any yield (W) in
kilotons to the correspording values given in "The Effects
of Atomic Weapons" for she nominel bomb.
ry
=
ra
Qy
(Wy)
1/3.
Where r,
andro
are distances for a given
pressure characteristic.
(Wp)
_
Ws
Where @ is total radiant energy (thermal
or nuclear) at a given distance.
(more)