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Old water in the ocean : the Antarctic radiocarbon reservoir
https://doi.org/10.18999/sumrua.11.5
https://doi.org/10.18999/sumrua.11.5d4927b78-af9d-4407-80a7-25989bcc8726
| 名前 / ファイル | ライセンス | アクション |
|---|---|---|
KJ00000187319.pdf (172.6 kB)
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| Item type | 紀要論文 / Departmental Bulletin Paper(1) | |||||
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| 公開日 | 2010-05-26 | |||||
| タイトル | ||||||
| タイトル | Old water in the ocean : the Antarctic radiocarbon reservoir | |||||
| 言語 | en | |||||
| 著者 |
Berkman, Paul Arthur
× Berkman, Paul Arthur× Jull, A.J.T.× Nakamura, Toshio |
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| アクセス権 | ||||||
| アクセス権 | open access | |||||
| アクセス権URI | http://purl.org/coar/access_right/c_abf2 | |||||
| 権利 | ||||||
| 言語 | ja | |||||
| 権利情報 | 名古屋大学年代測定資料研究センター 天然放射性元素測定小委員会 | |||||
| 権利 | ||||||
| 言語 | ja | |||||
| 権利情報 | 本文データは学協会の許諾に基づきCiNiiから複製したものである | |||||
| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | Radiocarbon in the Southern Ocean is dominated by the upwelling of "old" deep water from the northern hemisphere and, to a lesser extent, by "new" surface water which interacts with the atmosphere south of the Antarctic Convergence (Pickard and Emery 1982,Broecker 1987). This upwelling at the Antarctic Divergence enhances organic productivity and creates the oldest surface waters in the ocean, producing marine species with apparent radiocarbon ages that exceed a thousand years (Gordon and Harkness 1992). During the 20th century, however, the transfer of radiocarbon in this highly productive marine ecosystem has been altered by the atmospheric input of radiocarbon from fossil fuel combustion (Suess 1955) and nuclear explosions (Broecker and Walton 1959). To determine the magnitude of these anthropogenic impacts, calcareous marine species which were collected alive prior to 1945 were obtained from museum collections and compared to modern samples. Analyses of these calcareous marine species were used to produce the first pre-bomb radiocarbon reservoir correction from the Southern Ocean based on biogenic structures that precipitate in isotopic equilibrium with seawater, as indicated by _-^<13>C values around zero. These data indicate that radiocarbon age of surface seawater around Antarctica decreased nearly 500 years because of nuclear explosions in the atmosphere and that the pre-bomb radiocarbon reservoir correction in the Southern Ocean is around 1300 years (Berkman and Forman 1996). However, because of the scarcity of pre-bomb shells which were radiocarbon dated, there are limitations to applying the 1300-year reservoir correction in the circumpolar Southern Ocean. To address this limitation with the Antarctic marine radiocarbon reservoir correction from Berkman and Forman (1996), we have begun identifying additional pre-bomb biogenic carbonates which were collected alive from around Antarctica. Samples from an Antarctic scallop (Adamussium colbecki) and clam (Laternula elliptica), collected alive during Robert Falcon Scott's 'Terra Nova' expedition to McMurdo Sound from 1910-12,were obtained from the British Museum (Table 1). Radiocarbon age of the Laternula sample, which still had tissue remaining and was definitely living near the time of collection, complements earlier measurements. However, without additional data it is inappropriate to even speculate on the discrepancy with the Adamussium sample, which was more than 600 years older than any of the previous pre-bomb biogenic carbonates which were radiocarbon dated from around Antarctica. These measurements reinforce the need for canvasing the museums of the world to identify and radiocarbon-date biogenic carbonates which were collected alive, from around the continent before 1945-during the 'historic age' of Antarctic exploration. Calcareous marine fossils (which are widespread, abundant and well-preserved from the circum-Antarctica region) are critical for assessing the timing of climate, ice-sheet and sea-level impacts during the Late Quaternary and Holocene (Berkman 1992,Berkman et al. 1998). Further work is required to evaluate regional variations in the Antarctic marine radiocarbon reservoir to accurately constrain the ages of these fossils and accurately linking phenomena in the Antarctic coastal zone to global changes which have been observed from Marine Isotope Stage 3 (Hays et al. 1976) to the present. | |||||
| 言語 | en | |||||
| 内容記述 | ||||||
| 内容記述タイプ | Other | |||||
| 内容記述 | 第12回名古屋大学タンデトロン加速器質量分析計シンポジウム(平成11 (1999年度)報告 名古屋大学タンデトロン加速器質量分析計第1号機の研究実績と1号機,2号磯の利用計画 | |||||
| 言語 | ja | |||||
| 出版者 | ||||||
| 出版者 | 名古屋大学年代測定資料研究センター 天然放射性元素測定小委員会 | |||||
| 言語 | ja | |||||
| 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 | departmental bulletin paper | |||||
| 出版タイプ | ||||||
| 出版タイプ | VoR | |||||
| 出版タイプResource | http://purl.org/coar/version/c_970fb48d4fbd8a85 | |||||
| ID登録 | ||||||
| ID登録 | 10.18999/sumrua.11.5 | |||||
| ID登録タイプ | JaLC | |||||
| 関連情報 | ||||||
| 関連タイプ | isVersionOf | |||||
| 識別子タイプ | URI | |||||
| 関連識別子 | http://ci.nii.ac.jp/naid/110000475613/ | |||||
| 書誌情報 |
ja : 名古屋大学加速器質量分析計業績報告書 巻 11, p. 5-9, 発行日 2000-03 |
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| フォーマット | ||||||
| 値 | application/pdf | |||||
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| 値 | publisher | |||||
