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

We examined lateral distributions of Cs, Cs, Ra, and Ra 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 and Ra distributions differed along the three currents. Low levels of Cs were detected in the surface waters of the Oyashio Current (0.09-0.35 mBq/L), but it was