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the device was 750 times more powerful than the nominal
atomic bombs used at Crossroads eight years before and
very much more powerful than the Mike shot of 1952.
Bravo was a
surface shot,
detonated at 6:45 A.M.
The test may have been of greater yield than had been
calculated, but the effect would have been only the
production of an explosion proportionately greater than
that of Test Mike, either in immediate physical terms
or in the release of radiation products,
except that
the shot took place at a moment at which circumstances
were combining to produce mishap and human suffering,
the first such results attributable to a test program.
Because Bravo was detonated on a coral island,
its
energy and heat carried upward--its cloud reached an
altitude of 100,000 feet--a great volume of radioactive
particles which would fall down rather quickly to the
earth's surface when the turmoil of the nuclear fire
had been dissipated.
And on that morning there was
blowing across the Pacific an upper wind which would
carry the Bravo fallout not to the north,
as had been
expected, but eastward toward the inhabited atolls of
Rongelap,
Ailinginae,
and Rongerik,
the last the atoll on
which the Bikini people had spent a brief and difficult
interlude.
In the area of the eastward fallout,
some
eighty miles from Bikini, there also was a Japanese
long-line
Maru No.
fishing vessel,
the small
(100~-ton)
Fukuryu
5.
The Japanese organized a survey of the currents flowing
westward of Bikini,and during May and June of 1954 the survey