Intrusion of Fukushima-derived radiocaesium into subsurface water due to formation of mode waters in the North Pacific.

ABSTRACT: The Fukushima Dai-ichi Nuclear Power Plant accident in March 2011 released radiocaesium ((137)Cs and (134)Cs) into the North Pacific Ocean. Meridional transects of the vertical distribution of radiocaesium in seawater were measured along 147 °E and 155 °E in October-November 2012, 19 months after the accident. These measurements revealed subsurface peaks in radiocaesium concentrations at locations corresponding to two mode waters, Subtropical Mode Water and Central Mode Water. Mode water is a layer of almost vertically homogeneous water found over a large geographical area. Here we show that repeated formation of mode water during the two winter seasons after the Fukushima accident and subsequent outcropping into surface water transported radiocaesium downward and southward to subtropical

SUBMITTER: Kaeriyama H 

PROVIDER: S-EPMC4768088 | biostudies-literature | 2016 Feb

REPOSITORIES: biostudies-literature