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239Pu and 240Pu inventories and 240Pu/239Pu atom ratios in the equatorial Pacific Ocean water column
https://repo.qst.go.jp/records/46326
https://repo.qst.go.jp/records/463263664195f-532b-4450-a378-dcad1152bd31
| Item type | 学術雑誌論文 / Journal Article(1) | |||||
|---|---|---|---|---|---|---|
| 公開日 | 2012-05-21 | |||||
| タイトル | ||||||
| タイトル | 239Pu and 240Pu inventories and 240Pu/239Pu atom ratios in the equatorial Pacific Ocean water column | |||||
| 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 |
Yamada, Masatoshi
× Yamada, Masatoshi× Zheng, Jian× 山田 正俊× 鄭 建 |
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| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | The 239+240Pu concentrations and 240Pu/239Pu atom ratios were determined by alpha spectrometry and double-focusing SF-ICP-MS for seawater samples from two stations, one at the equator and the other in the equatorial South Pacific Ocean. The 239Pu, 240Pu and 239+240Pu inventories over the depth interval 0-3000 m at the equator station were10.4 +/- 0.5, 8.9 +/- 0.5 and 19.3 +/- 0.9 Bq m-2, respectively. No noticeable difference was observed in 239Pu, 240Pu and 239+240Pu inventories over the depth interval 0-3000 m between the two stations. The total 239+240Pu inventories were significantly higher than that of the expected deposition density of global fallout. The decreasing rates of 239+240Pu over the depth interval 0-1000 m were estimated to be 0.89 +/- 0.07 Bq m-2 yr-1 at the equator station and 0.16 +/- 0.07 Bq m-2 yr-1 at the equatorial South Pacific Ocean station. The obtained 240Pu/239Pu atom ratios in the equatorial Pacific Ocean were higher than the mean global fallout ratio of 0.18. These high atom ratios proved the existence of close-in tropospheric fallout Pu from the Pacific Proving Grounds (PPG) in the Marshall Islands. The 239+240Pu inventories originating from the close-in fallout in the full depth of the water column were estimated to be 11.1 Bq m-2 at the equator station and 7.1 Bq m-2 at the equatorial South Pacific Ocean station, and the relative percentages of close-in fallout Pu were 40 % at the former and 34 % at the latter. A significant amount of close-in tropospheric fallout Pu originating from the PPG has been transported to deep layers below the 1000 m depth in the equatorial Pacific Ocean. |
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| 書誌情報 |
Science of The Total Environment 巻 430, 号 15, p. 20-27, 発行日 2012-07 |
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| ISSN | ||||||
| 収録物識別子タイプ | ISSN | |||||
| 収録物識別子 | 0048-9697 | |||||
