Meridional distribution of Fukushima-derived radiocesium in surface seawater along a trans-Pacific line from the Arctic to Antarctic Oceans in summer 2012

In summer 2012, we measured activity concentration of radiocesium in surface seawater collected in the Arctic Ocean, Bering Sea, western Pacific Ocean, and Antarctic Ocean. The radiocesium derived from the Fukushima Dai-ichi Nuclear Power Plant accident in March 2011 was found in the Bering Sea and western North Pacific between 25 deg N and 63 deg N, which agrees with model simulation results of atmospheric deposition. A semi-synoptic view suggests that a main body of radiocesium discharged directly had been transported eastward to 170 deg W. northward to 50 deg N, and southward to 30 deg N by summer 2012, about one and half years after the accident. (author)