Reconstruction of anthropogenic I temporal variation in the Japan Sea using a coral core sample.

The anthropogenic long-lived radionuclide I is receiving increased attraction as a new oceanic tracer in addition to usage as a fingerprint of radionuclide contamination of the marine environment. To demonstrate the robustness of I as an oceanic tracer in the Northwest Pacific area, specifically in the Japan Sea, the input history of I to surface seawater was reconstructed using a hermatypic coral core sample from Iki Island in the Tsushima strait. Iodine isotopes in each annual band were measured using AMS and ICP-MS after appropriate pre-treatments of small amounts of coral powder.