on every island, but emphasis was given kind of data obtained for each of the pre- to — and proportionately larger numbers dominant isotopes on each of the islands, of samples taken on — those islands which 905. values for 0-15 cm core samples on were known to have been sites for nuclear JANETare plotted in Fig. 147. testing activity or to have been subjected Table 215 presents geometric mean to large amounts of fallout from such values and ranges for the four predominant activity. radionuclides on islands from ALICE Two types of soil samples were taken through WILMA. On islands where there on each island: "surface' ‘ and "profile." are significant differences in activity At "surface'' sampling locations, two levels between densely and sparsely samples were taken — one a 30-cm” xX 15- vegetated areas, data for both are given. cm-deep core, and the second a composite Similar data for groups of southern islands of two 30-cm” x 5-cm-deep cores, are shown in Table 216. At "profile'' sampling’locations, 100-cm? "Profile" samples showed a wide range samples were taken from the side wall of activity distributions as a function of of a trench dug for the purpose. Nominal depth on different parts of the Atoll, depth increments for the profile samples amples of the types found are given in were 0 to 2, 2to 5, 5to10, 10 to 15, 15 Figs. 148-151. to 25, and 25 to 35 cm, and at 10-cm in this area are not very meaningful, increments to total depth. Fig. 148 shows the profile distribution Total depth Ex- Although generalizations for profile samples varied from 35 to normally found on the southern islands, 185 cm, depending on the distribution ex- Here the activity levels are usually low pected from the testing history of the through the full range of depths sampled. island being sampled, Some sampling locations show concentra- In general, the predominant Species tions decreasing somewhat from the sur- found in the soil samples are 905, 137 og, 239 pu, and 8065, 404 3 e, 10ley face through the first 10 or 20 em of soil, 102mpy 1256) 1335, 1346, 1525, 1945, 1555, u, 207 Bi, 2266p, 235, Figure 149 shows the type of distribution often found inland on islands subjected to fallout but not to construction or other 2385u and 241 am are also present in ground-zero earthmoving activities — i.e., some or all of the samples. a rapid and fairly steady decrease of As was the case for external gamma levels, small activity levels from the surface to total amounts of radioactive species on the depth, southern islands (SAM to KEITH) are found on beaches and exposed areas on distributed more or less uniformly over these same islands — i.e., uniform or the entire land area. slowly decreasing activity levels from On islands where Figure 150 shows the distribution larger amounts of activity are present, the surface to total depth. the highest levels of all species are found shows a distribution pattern found occasion- at the island centers or in proximity to ally on islands which have been the sites ground-zero sites, usually related ina for tests or have been subjected to con- direct way to the vegetation density in the struction and earthmoving activities immediate area. (primarily IRENE, JANET, PEARL, As an example of the Figure 151