A Study on the Vertical Transport of 90Sr and 137Cs in the Surface Waters of the Seas around Japan

Abstract

A model was established for estimation of vertical transport of Sr-90 and Cs-137 in surface layer of the seas. In the upper 500 meters of the open seas around Japan, approximate residence times concerning vertical transport are estimated as 5 years for Sr-90 and 3 years for Cs-137. For the coastal waters, the residence time seems to be lower than those on open seas. Slight differences of the rates of vertical transport are observed among three regions and between Sr-90 and Cs-137.