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Sediment core record of global fallout and Bikini close-in fallout Pu in Sagami Bay, western Northwest Pacific margin
https://repo.qst.go.jp/records/43431
https://repo.qst.go.jp/records/43431391d3eb5-f40d-4ade-8f33-f97be182eebf
Item type | 学術雑誌論文 / Journal Article(1) | |||||
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公開日 | 2004-06-29 | |||||
タイトル | ||||||
タイトル | Sediment core record of global fallout and Bikini close-in fallout Pu in Sagami Bay, western Northwest Pacific margin | |||||
言語 | ||||||
言語 | eng | |||||
資源タイプ | ||||||
資源タイプ識別子 | http://purl.org/coar/resource_type/c_6501 | |||||
資源タイプ | journal article | |||||
アクセス権 | ||||||
アクセス権 | metadata only access | |||||
アクセス権URI | http://purl.org/coar/access_right/c_14cb | |||||
著者 |
Zheng, Jian
× Zheng, Jian× Yamada, Masatoshi× 鄭 建× 山田 正俊 |
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抄録 | ||||||
内容記述タイプ | Abstract | |||||
内容記述 | The total 239+240Pu activity and 240Pu/239Pu atom ratio in the sediments in Sagami Bay of the western Northwest Pacific margin were investigated using ICP-MS with a shield torch system. 239+240Pu inventories in the examined sediment cores were found to be much higher than those predicted from atmospheric global fallout (42 MBq/km2) at the same latitude. In addition, elevated 240Pu/239Pu atom ratios ranging from 0.22 to 0.28 were observed in the sediment samples. Based on the vertical profiles of 239+240Pu and characterized 240Pu/239Pu atom ratios in a sediment core collected in the center of Sagami Bay, we identify two distinct sources of fallout Pu in the bay: the global stratospheric fallout with characteristic 240Pu/239Pu ratio of 0.18 and the transported close-in fallout derived from Bikini and Enewetak surface nuclear weapon test series in the 1950s. We propose that the Pu transportation was mainly due to oceanic processes, e.g. through the North Equatorial Current and Kuroshio Current. Using a two fallout end-member model, we find that the contribution of Bikini close-in fallout Pu ranged from 44 to 59 % in Sagami Bay sediments. To our best knowledge, this is the first report that Pu contamination which originated from Bikini and Enewetak nuclear weapon test series in the 1950s has extended westwards as far as the Japanese coast. | |||||
書誌情報 |
Environmental Science & Technology 巻 38, 号 13, p. 3498-3504, 発行日 2004-07 |
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ISSN | ||||||
収録物識別子タイプ | ISSN | |||||
収録物識別子 | 0013-936X |