DAtard The main neturally-occurring ms wb Ck . potassiun-40 with a half 1if & Rx] renain constant throughout the ccean. One liter of sen water enits gh. KO gamma rays per minute. any atditional geuma raGiation shown in Table 1 is dee to contauinetion. Throughout the PPG area the predLosctivity of the seca water is fairly constant with tue excaption cf ong layer of water botyvoen &00 and 1290 withers found ror Atoll et steticas 6, 7, 8, and 29. This exen is om the cdee cf ea large eddy current found erovad Enicet, horcireficr reTerved to 9s the "Bilint eddy” syste (Firives &3-Ch), ° oN 7 * ‘. *, ° : 4 a in . ‘S Sey, %. _ ae ty, by Sele ae yp we ° a ed - on