Page 4 - Lesson 12.xps

Module - V Nuclear Warfare

Warfare and
Its Types 12.2 Energy Yield of Nuclear Explosion

The 'yield' of a nuclear weapon is a measure of the amount of explosive energy it can
produce. The yield is expressed in terms of the quantity of TNT that would generate
the same amount of energy when it explodes. Thus, a 1 Kiloton (KT) nuclear weapon
is one which produces the same amount of energy in an explosion as does 1 kiloton
Note (or 1,000 tons) of TNT. Similarly a one megaton (MT) weapon would have the energy
equivalent of 1 million tons of TNT.

12.2.1 Types of Bursts

A nuclear bomb can be made to burst on ground, air or higher in the atmosphere.
Depending on the location or point of burst in relation to the surface of the earth, the
effects of a nuclear blast varies. The point of nuclear explosion may be therefore
classified as follows: -

(a) Exo-Atmospheric: A burst occurring outside the earth's atmosphere (over
30kms above the earth's surface) is called an exo-atmospheric burst.
(b) Endo-Atmospheric: A burst, which occurs within the earth's atmosphere, is
called an endo -atmospheric burst. These can be further divided into:-

(i) High Altitude Air Burst : A high altitude burst is defined as the one in
which the explosion takes place at an altitude in excess of 30,000 m. At
these heights, the air density is so low that the interaction of the weapon
energy with the surroundings is markedly different from that at lower
altitudes. The effects of blast, thermal and nuclear radiations of such bursts
are negligible at ground level but radar and wireless communications may
get affected over a large area for a long duration.
(ii) Air Burst: When a nuclear explosion takes place below 30,000 m of
altitude, the weapon residue immediately incorporates material from the
surrounding medium and forms an intensely hot and luminous mass, which
is roughly spherical in shape. For an airburst, the height of burst should be
such that the fireball does not touch the surface of earth.

(iii) Surface or Ground Burst : When the point of burst is such that the
fireball touches the surface, then it is a surface burst.
(iv) Sub-Surface Burst : When the point of burst is beneath the ground, it is
a subsurface burst. A very shallow burst is indistinguishable from a surface
burst because the fireball will still be produced above the ground. In a
deeper burst, a gas bubble will be formed, instead of fireball.
(v) Underwater Burst: When the point of burst is under the sea, it is an

underwater burst.

28
28
MILITARY STUDIES