Geoscience Reference
In-Depth Information
On the night of July 8, 1962, the United States detonated a 1.4-megaton thermonuclear device
at an altitude of 240 miles (400 kilometers) above Johnston Island in the mid-Pacific in what
was called the Starfish Prime test. It was monitored by hundreds of scientific instruments at
widespread installations across the Pacific and outer space. Owing to a physicist's miscalcula-
tions, the EMP was far larger in size than expected, with the result that many of the measure-
ment systems went completely off the scales for which they had been calibrated. In spite of the
fact that the automobiles, electric power grid, telecommunication devices, and other electronic
devices of that day were far less susceptible to an EMP than today's microelectronics, there
were numerous reports of streetlight failures and automobile starting-system problems on the
island of Oahu, and telephone service failures on the island of Kauai, roughly 780 miles (1400
kilometers) away from the detonation site.
On the morning of October 22, 1962, the Soviets detonated a 300-kiloton thermonuclear
device over central Kazakhstan at an altitude of 174 miles (290 kilometers). Though the inten-
tion of the test was to study the EMP effects, the Soviets were quite surprised by the magnitude
of those effects. A major aboveground telephone line was knocked out by induced currents es-
timated at 1,500 to 3,400 amps, and a 600-mile-long (1000 kilometer) underground power line
was also knocked out. The EMP started a number of electrical fires, including one at the city of
Karagandy's electrical power plant. Radios were damaged at a range of 360 miles (600 kilo-
meters) from detonation, and a radar was disabled at a range of 600 miles (1000 kilometers).
Additionally, a number of the military's diesel generators were damaged. Note that all of these
items were less susceptible to EMP damage than today's electronics containing integrated cir-
cuits and microelectronic controls, except for those electronics specifically designed to be
hardened against EMP damage.
Subsequent analysis of the thermonuclear devices used in both the American Starfish test,
and the Russian Kazakhstan test, show that these devices were quite inefficient at generating
high levels of EMP, as compared to much smaller and simpler nuclear fission bombs, such as
the more primitive 500-kiloton device known as the Mark 18, first tested by the Americans in
1952. There are a number of countries in today's world, including Pakistan and Israel, that have
more sophisticated nuclear devices at their command, and with the breakup of the Soviet Union
combined with wealthy individuals from places like Saudi Arabia contributing to the support of
terrorist organizations, such devices may well have already fallen into the hands of terrorists, or
will eventually do so.
