ABSTRACT
The first of five areas of study was the oceanography of the water within a 300-mile radius of
Bikini Atoll prior to and during the operation. The objectives were to measure oceanographic
parameters affecting the fallout pattern and to determine the radioactive background within the
ocean.
The results of this study have been presented as a separate report, WIT—1349.
A par-
tial abstract is presented in Chapter 1 of this report.
The second study (Chapter 2) involved the determination of fallout by the use of oceanographic
methods. In addition to the collection of samples for this and other projects, it was the objective of this survey to measure the intensity and extent of fallout, to convert this to equivalent
land values, and to relate the in situ fallout distribution to the oceanographic parameters.
The results of the oceanographic fallout surveys show that: (1) Shot Cherokee (an air burst)
produced no measurable fallout; (2) Shot Flathead (a water burst) produced fallout that mixed
downward into the ocean water at a rate of 3.5 m/hr andattained an average penetration depth
amounting to 75 percent of thermocline depth; (3) Shot Navajo (a water burst) produced fallout
with a mixing rate of 2.3 m/hr and attained an averagepenetration depth of 75 percent of thermocline depth, and although Navajo had a total yield of
‘it produced an area of less than 150
mi” of hazardous dose rates; (4) Shot Tewa (a combination water-and-land burst) exhibited a mixing rate similar to Flathead (3.8 m/hr) and an average penetrationdepth similar to Flathead and
Navajo (75 percent of thermocline depth); this 5-Mt,|
_
: produced
hazardous dose rates over an area exceeding 2,000 mi’; (5) Shot Zuni (a land burst)fallout mixed
downward at 11 m/hr and reached an average penetration depth of 107 percent of thermocline
depth; (6) dose rate in fallout resulting from nuclear detonations is directly proportional to the
fraction of fission yield; and (7) the cube-root scaling laws are valid for fallout dose rates from
nuclear detonations over the range from 0.4 to 5.0 Mt.
The third study (Chapter 3) concerned oceanographic and fallout measurementsin the lagoon
circulation for various wind conditions and, from this, predict the movementof radioactive
water from a knowledge of the winds. The results of the lagoon oceanographic studies have been
presented in WIT-1349. The measurements show that the movement of radioactivity with the
lagoon water corresponds to the observed current movements. These same measurements have
been used in WT— 1349 to develop a method of predicting the distribution of radioactivity within
the lagoon from a knowledge of current directions and velocities.
The fourth interrelated field of work (Chapter 4) involved the installation and maintenance of
anchored instrument stations in the deep ocean water. The results of this effort have such military and scientific implications that the complete procedurefor installing these stations is included as an appendix.
The last study (Chapter 5) was a radiochemical examination of fallout in the marine biosphere.
The results show the distribution of fallout material in the water, the air above the water, the
sediments, and marine life. These studies were carried out in the lagoon as well as in the open
ocean. Marine organismsselectively absorb such nonfission products as Mn*‘, Co, Co®, and
zn®5_ Oceanic contamination was detected from the Eniwetok Proving Grounds to a latitude of
11 degrees south after the completion of the test series.