The Southern Hemisphere Ocean Tracer Studies (SHOTS) project

摘要

Global fallout radionuclides, mainly injected to the ocean surface from atmospheric nuclear weapons tests, have been used for about five decades to study marine environment processes. Conservative (~3H, ~(14)C, ~(90)Sr,~ (129)1,~(137)Cs and others) and non-conservative (~(238)Pu, ~(239)Pu, ~(240)Pu, ~(241)Am and others) radionuclides have been used for surface, medium and deep water studies (e.g. Livingston and Povinec, 2002). The peak concentrations of the anthropogenic radionuclides in the atmosphere of the northern hemisphere were observed in 1963, and with one year delay in surface waters of northern oceans and seas. Mapping of this deposition revealed that the major injection on the ocean surface occurred at mid-latitudes of the western North Pacific (Aoyama et al., 2006b).