Anthropogenic radionuclides in seawater of the Japan Sea; The Results of recent observations and the temporal change of concentrations

Ito, Toshimichi ; Aramaki, Takafumi*; Otosaka, Shigeyoshi  ; Suzuki, Takashi  ; Togawa, Orihiko ; Kobayashi, Takuya ; Kawamura, Hideyuki  ; Amano, Hikaru; Senju, Tomoharu*; Chaykovskaya, E. L.*; Lishavskaya, T. S.*; Karasev, E. V.*; Novichkov, V. P.*; Scherbinin, A. F.*; Tkalin, A. V.*; Volkov, Y. N.*

During 1996-2002, a wide-area research project on anthropogenic radionuclides was done in the Japanese and Russian EEZ of the Japan Sea to investigate their migration. As the results of expeditions in 2001 and 2002, (1) the concentrations and distributions of radionuclides are similar to the results of previous, (2) inventories of these radionuclides indicate accumulation in the Japan Sea seawater compared to the amounts supplied by global fallout, (3) Sr and Cs concentrations in intermediate layer show temporal variations, and 4) the variations may reflect the water mass movement in upper part of the Japan Sea.