Geochemical cycles in the marginal seas around Japan Islands from spatial distributions of multi-radionuclides

2014 Fiscal Year Final Research Report

• Project/Area Number: 24510011
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Environmental dynamic analysis
• Research Institution: Kanazawa University
• Principal Investigator: INOUE Mutsuo 金沢大学, 環日本海域環境研究センター, 助教 (60283090)
• Co-Investigator(Kenkyū-buntansha): YAMAMOTO Masayoshi 金沢大学, 環日本海域環境研究センター, 教授 (10121295) ; NAGAO Seiya 金沢大学, 環日本海域環境研究センター, 教授 (20343014) ; HAMAJIMA Yasunori 金沢大学, 環日本海域環境研究センター, 助教 (60172970)
• Co-Investigator(Renkei-kenkyūsha): FUJIMOTO Ken 水産総合研究センター中央水産研究所, 海洋生産部, 研究員 (20371841)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 海洋化学 / 放射性核種 / ガンマ線計測 / 日本海 / 物質循環

Outline of Final Research Achievements

We applied low-background gamma-spectrometry to conduct an investigations of spatial variations of 226Ra, 228Ra, 137Cs, 134Cs, 7Be, and 228Th activities in marginal seas around the Japan Islands; the Sea of Japan, the East China Sea, and the southwestern Okhotsk Sea. We could elucidate the flow patterns of water masses (e.g., lateral and vertical water circulation) from 228Ra/226Ra ratio and 137Cs and 7Be activities and migration pattern of particles and reactive components from 228Th/228Ra ratio in these areas. We also clarified contamination levels of radiocesium in these areas after the Fukushima Dai-ichi Nuclear Power Plant accident from 134Cs and 137Cs activities.

Free Research Field

海洋化学