論文

査読有り
2017年10月

Processes affecting long-term changes in Cs-137 concentration in surface sediments off Fukushima

JOURNAL OF OCEANOGRAPHY
  • Shigeyoshi Otosaka

73
5
開始ページ
559
終了ページ
570
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.1007/s10872-017-0421-5
出版者・発行元
SPRINGER

Temporal changes in cesium-137 (Cs-137) concentrations in the surface (0-10 cm) layer of seabed sediment were quantified from continuous observation data at 71 stations within a 150-km radius of the Fukushima Daiichi Nuclear Power Plant, and the primary processes affecting temporal changes were identified. From March 2011 to the end of 2015, about 80% of the initially deposited Cs-137 in the surface sediment in the coastal region (bottom depth <= 100 m) region has dissipated (radioactive decay is not included). Such a remarkable change in the Cs-137 concentration was not observed in the offshore (> 100 m) region. This paper focuses on the following three processes that affected the decrease in the Cs-137 concentrations, and assesses their relative importance; (1) resuspension and transport of Cs-137-bound sediment, (2) desorption of Cs-137 from the sediment, and (3) dilution of Cs-137 by vertical mixing of sediment. Consequently, it was estimated that the first two processes together have potentially contributed to reduce the Cs-137 inventory in the top 10 cm of the coastal region by at most 35%. Furthermore, by applying a pulse input sediment mixing model to the observed vertical distribution of sedimentary Cs-137, it was also estimated that more than 43% of the Cs-137 in the surface sediment was transported to deeper sediment layers by vertical mixing of the sediment. This indicates that the decrease of Cs-137 concentrations in coastal sediments was mainly affected by mixing of Cs-137-bound surface sediment with less contaminated sediment in the deeper layers.

リンク情報
DOI
https://doi.org/10.1007/s10872-017-0421-5
Web of Science
https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000412313300004&DestApp=WOS_CPL
URL
http://orcid.org/0000-0003-2087-9676
ID情報
  • DOI : 10.1007/s10872-017-0421-5
  • ISSN : 0916-8370
  • eISSN : 1573-868X
  • ORCIDのPut Code : 31511978
  • Web of Science ID : WOS:000412313300004

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