1.
aNTRCDUCTICN
The several purposes of studying the radioactivity background and oceanogriuphic conditions of the Pacific Proving
Ground are:
(1)
Te evaluate effects of RELWING events on the
radioactivity content in water, marine organisms, eat bottom
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sedinents.
litate accurate recenstructicn fF tho
equivalent lend falicut patterm from measureneats by ships and
airereft and enable future fallout surveys to be mace with
less effort.
(3)
To unde'stend the fallout problen at see
‘se, and to provide cceavo.vaphic assistance to the Task Force.
Previous oceénograrmic deta in the PPG are primerily fron
collections made during
the period Merch to August, 29:6, in
connection with CROSSPO4DS aia from Japanese hydrogranhie
These ere mostly measure
$
investigations during 1933-1ch1.
menis of density end thermal i:teucture and cf some checice
constituents.
Although the ¢ita are many, they are nehurer
closely spaced mer synoptic.
The sapanese made several crouse
procurs
fe
ings in, the area with a reseurch vessel curing June 195: to
information in suoport of a claim of damage to their
tuna fishery.
In analyzing the CASTLE :'allout results, the need was
evident for more explicit date on currents, rates of vertice:
penetration and acorizontal mixing to properly interpret fallout
measurements in the cper sea.
COp.
LinyHeug
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