and/or narrow islands,
however, a correction is required for the aerial
measurement and uncertainty is introduced in the final average concentration
from the aerial measurement (Tipton and Meibaum, 1981).
The maximum difference observed between the two methods is about a factor
of 3 or 4 for smaller islands, and, because of the uncertainties in the two
methods, it is reasonable to assume that the average !3’Cs surface soil
concentration is somewhere between the results listed for the two methods.
more
soil
profile
samples
are
collected
and
analyzed,
the
As
average
concentration will probably approachwthe average concentration determined by
the aerial measurement.
,
Listed in Appendix B (Tables B-1 to B-14) are the comparative results of
the
individual
soil
profiles
for
each island on Bikini Atoll
corresponding aerial activity contour.
how well
the soil
and the
This comparison gives a better idea of
profile data match the aerial
data because each sample is
compared with the associated aerial contour in which it is located rather than
the island average.
Thus,
the error introduced by looking at island averages
where no soil profiles were taken in the center of the island is eliminated.
It does not,
of course,
improve in any way the resolution of the aerial
System, so there is still an averaging effect within a contour.
Also,
|
an uncertainty still exists in the precise location of the soil
profile sample and the small size of the soil
profile.
The sample locations
were marked on maps carried by the field teams but they are approximate
'
locations (see Appendix A).
The exact location of the soil profile sample
could easily be several meters from where we have it recorded on the maps.
Thus, when the location is near the boundary of two or more contour regions,
the true soil profile location could fall in any of the nearby aerial contour
regions.
We would
expect, therefore,
that the correlations would not always be
exact because of the uncertainty in the soil profile location and also because
the soil profile analysis involves a very small area of the soil surface,
while the aerial measurement integrates a much larger surface area. Overall,
the correlation between the soil profile and aerial results are reasonably
good.
The median and mean radionuclide concentrations for '37cs, 99sr,
239+240py and 24lam for each island for each soil increment to a depth of
60 cm are
5000325.
given
in
Tables
5
to 30.
Data are also given for. the average
19