13
do not give the distribution of radioactivity at any one time
for the entire survey area.
As mentioned above, the values
given are those at time of collection and can not be corrected
°.
readily to a common date because of the repeated addition to
}
~
the waters being sampled of radioactive materials from the test-
ing program.
Gamma Ray Spectra:
Gamma ray spectra were run at the
EMBL on a Gamma Spectrometer type TM-10-A developed by the In-
oe
}
se
°-
struments Branch, HASL, NYOO.
RESULTS AND CONCLUSIONS
;
Plankton and Water Temperatures:
f-
¥
;
The average value of
radioactivity in plankton was 71,000 d/m/g(wet), with the range
from 1,300 to 1,100,000 (Table 1).
10
3
e
ton was about 7,100 times the average value for surface water
(10,000 d/m/l; Table 3).
t
a
The average value for plank-
‘The minimum level of plankton activity,
1,300 d/m/g, was almost as high as the maximum level of 1,700
d/m/g found during the Troll survey, and indicates that the en-
nr
{
tire area covered by the WALTON survey was contaminated to some
degree.
The contour curves of plankton activity, based on station
values as of the day of collection (June 11 to June 21), are
.
Ps -
Shown in Pigure 10.
Radioactivity was at a maximum in the re-
.
gion immediately north of Bikini Atoll and diminished rapidly
‘
southward and gradually northwestward,
3
north and northwest.
suggesting fallout to the
There was a general decrease in activity
westward from Bikini with the exception of a tongue of higher
re,