Migration of the FDNPP-derived Cs-134 and Cs-137 along with Ra-226 and Ra-228 concentrations across the northwestern North Pacific Ocean

摘要

We examined lateral distributions of Cs-134, Cs-137, Ra-226, and Ra-228 in the surface seawaters around the Kuril Islands and the Kamchatka Peninsula in the northwestern North Pacific "Ocean during June 2014. The sampling area included three water current areas, the Oyashio Current, the current from the Okhotsk Sea, and the coastal current along the east Kamchatka Peninsula. Ra-226 and Ra-228 distributions differed along the three currents. Low levels of Cs-134 were detected in the surface waters of the Oyashio Current (0.09-035 mBq/L), but it was