68
Tewa site, has been transported along the reef perimeter masking the Tewa
ratio signature in surface sediments in the Crater area environs.
5.1~4
Europium-155
The areal distribution of
ments is shown in Figure 14.
155
Fu in lagoon surface sedi-
The highest concentrations were found along the
northern sector of the lagoon at Stations B-19 and B-18.
At most other
Stations across the lagoon, the areal distribution of 155 Eu is very similar to
the distributions of
239+240
Pu.
Considering the chronology of the testing
schedule at Bikini, the short (1.91 year) physical half-life of this radionuclide may be responsible for both the relatively low Soe concentrations
measured in Station B-30 sediments (assuming Baker test debris was sampled
here), and the relatively high concentrations found in sediments in the north
central sector of the lagoon.
show similar
239+249,
Puf
155
The nature in which large areas of the lagoon
~~Eu or
241 4,195 Eu ratios indicate that the distribu-
tion of these three radionuclides from individual tests are similar.
the relatively short half-life of
155
Further,
Eu is useful in separating the extent to
which debris produced at different times is distributed in areas containing
radioactivity from several detonations.
5.1-5
Cesium-137
The distribution of
in Figure 15,
137
Cs in lagoon sediments is shown
The highest concentration of '376, measured was found in sedi-
ments collected at Station P-20.
The distribution of 23942405, 1376, ratios
across the lagoon illustrates that at least two areal distributions of V37e,
are responsible for the concentrations measured:
one centered at Station B-20
in the northwest quadrant; and one centered in the Zuni Crater area.
distribution of
239+240,,137
Pu/
The
Cs ratios to the east of Station B-20 show a
rapid increase from a ratio of 3.92 at Station B-20 to a ratio of 184 at