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Transport process of radionuclides in the East China Sea
https://repo.qst.go.jp/records/68708
https://repo.qst.go.jp/records/6870805d3f174-e45e-4cd4-b92f-51a6043b202f
| Item type | 会議発表用資料 / Presentation(1) | |||||
|---|---|---|---|---|---|---|
| 公開日 | 2006-10-05 | |||||
| タイトル | ||||||
| タイトル | Transport process of radionuclides in the East China Sea | |||||
| 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 object | |||||
| 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× Aono, Tatsuo× Zheng, Jian× 山田 正俊× 青野 辰雄× 鄭 建 |
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| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | Settling particles were collected from six stations in the Okinawa Trough and the East China Sea continental margin. Activities of U isotopes, Th isotopes, Pu isotopes and Pb-210 were determined for the particles to elucidate their transport processes. Surface sediments samples were also analyzed for their isotopes. There was a tendency for Pb-210 activities to increase almost linearly with depth from 72 m on the continental shelf edge to 1019 m in the Okinawa Trough. Increasing Pb-210 activities in settling particles with depth on the continental margin may be attributable to enhanced Pb-210 scavenging by particles and removal near the front. There also was a clear tendency for total mass fluxes and the radionuclide fluxes to increase with depth, with an especially large increase near-bottom. The ratio of the observed Pb-210 flux to the Pb-210 deficiency flux in the near-bottom traps ranged between 8.9 and 46. These high values show a strong Pb-210 excess which would be attributable to large advective import to the near-bottom and resuspended particles that have settled through the water column but have not become incorporated into the sediments. High variability of radionuclide fluxes occurred in very short time periods. Activities of -238, Th-232, Th-230, Th-228, Pb-210 and Pu-239+240 in settling particles were significantly higher than those in the underlying surface sediments. These results can be attributed to episodic near-bottom transport of fine particles which undergo repeated resuspension and flow down the continental slope with the nepheloid layer. | |||||
| 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 | 7th International Symposium on Environmental Geochemistry | |||||
| 発表年月日 | ||||||
| 日付 | 2006-09-27 | |||||
| 日付タイプ | Issued | |||||
