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Particle fluxes and scavenging of radionuclides in the western Northwest Pacific Ocean
https://repo.qst.go.jp/records/69078
https://repo.qst.go.jp/records/6907892435293-df26-4122-b3d3-04856e8e41e6
| アイテムタイプ | 会議発表用資料 / Presentation(1) | |||||
|---|---|---|---|---|---|---|
| 公開日 | 2007-08-28 | |||||
| タイトル | ||||||
| タイトル | Particle fluxes and scavenging of radionuclides in the western Northwest Pacific Ocean | |||||
| 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_c94f | |||||
| 資源タイプ | conference output | |||||
| 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 | 230Th, 210Pb and Pu are particle-reactive radionuclides and they are therefore removed from the water column by a scavenging process. Because of substantial input of terrigeneous materials from riverine input and atmospheric input of continental dust, and the relatively high primary productivity, the western Northwest Pacific margins may be important for removal of reactive radionuclides by scavenging. The objectives of this study are to measure the activities of 210Pb, 230Th and 239,240Pu in settling particles in the western Northwest Pacific margin and to discuss the removal of reactive radionuclides by scavenging and particle transport processes on the margins of the western Northwest Pacific Ocean. A mooring of three conical time-series sediment traps was deployed at two sites in the western Northwest Pacific Ocean for nine months. The analytical procedure for 210Pb, 230Th and 239,240Pu was essentially the same as that described by Anderson and Fleer (1982). A double-focusing sector-field ICP-MS instrument was used for the determination of the Th and Pu isotopes in settling particle samples (Zheng and Yamada, 2006). Total mass fluxes, 210Pb fluxes, 230Th fluxes and 239,240Pu fluxes showed large seasonal variations and their weighted mean fluxes tended to increase with depth, with an especially large increase near-bottom. The ratios of the observed 210Pb fluxes to the 210Pb deficiency fluxes in the near-bottom traps ranged between 1.22 and 2.63. The mean total 230Th fluxes at the near-bottom traps were 4.2-6.7 times higher than that expected from production in the overlying water column. The high fluxes of particulate 210Pb, 230Th and 239,240Pu collected by the near-bottom traps reflect a combination of enhanced scavenging of dissolved 210Pb, 230Th and 239,240Pu by the high fluxes of particles in the region, as well as the lateral redistribution of particulate matter itself by downslope gravitational settling and by alongshore transport by currents. |
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| 会議概要（会議名, 開催地, 会期, 主催者等） | ||||||
| 内容記述タイプ | Other | |||||
| 内容記述 | 17th V. M. Goldschmidt Conference | |||||
| 発表年月日 | ||||||
| 日付 | 2007-08-24 | |||||
| 日付タイプ | Issued | |||||
