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日本海大和堆および沿岸周辺海域における^<226>Ra,^<228>Raおよび^<137>Cs濃度の鉛直分布
- フォーマット:
- 論文
- 責任表示:
- 田中, 究 ; 井上, 睦夫 ; 御園生, 淳 ; 小村, 和久
- 言語:
- 日本語
- 出版情報:
- 日本地球化学会 = Geochemical Society of Japan, 2006-08-25
- 著者名:
- 掲載情報:
- 地球化学 = Geochemical Journal
- ISSN:
- 0386-4073
- 巻:
- 40
- 通号:
- 3
- 開始ページ:
- 167
- 終了ページ:
- 176
- バージョン:
- publisher
- 概要:
- To obtain implications for the vertical water mixing within the Sea of Japan, we collected 29 water samples from 2 sites around the Yamato Ridge (3,685 m and 2,610 m depth), and 24 samples from coastal areas (12 sites) along the Japan Islan … d (85-475 m depth) in May-June 2004 and 2005. ^<226>Ra (t_<1/2>=1,600 y), ^<228>Ra (5.75 y) and ^<137>Cs (30.2 y) were quantitatively coprecipitated by BaSO4 and AMP using 20-60 L of water samples, and their activities were measured by low-background y-spectrometry. From surface to the Upper Proper water (1-1,000 m), the ^<228>Ra and ^<137>Cs activities exhibit gradual decrease from 1.8-0.2 mBq/L and 1.7-0.2 mBq/L, respectively. From the gradient of ^<228>Ra activity, the vertical eddy diffusivity was calculated to be 〜6 cm^2/s around the Yamato Ridge. In the Deep Proper Water (>1,000 m), the ^<228>Ra activity keeps approximately constant (〜0.2 mBq/L). These vertical distributions are reflecting the intense vertical mixing compared with those in other oceans. For deep sites of coastal areas (>〜250 m depth), the ^<228>Ra activities of bottom waters are notably lower (〜0.5 mBq/L) than those of shallow sites (<〜250 m) (0.7-2.2 mBq/L). The exchange of radium between shallow and deep water is inhibited by the boundary layer (thermocline at 〜250 m depth). 続きを見る
- URL:
- http://hdl.handle.net/2297/32416
類似資料:
金沢大学自然計測応用研究センター |
金沢大学環日本海域環境研究センター |
金沢大学環日本海域環境研究センター = Institute of Nature and Environmental Technology Kanazawa University |
日本地球化学会 = Geochemical Society of Japan |
金沢大学環日本海域環境研究センター = Institute of Nature and Environmental Technology, Kanazawa University, Japan |
金沢大学自然計測応用研究センター |
植物地理・分類学会 The Society for the Study of Phytogeography and Taxonomy / 日本植物分類学会 The Japanese Society for Plant Systematics (JSPS) |
土木学会 = Japan Society of Civil Engineers |
金沢大学自然計測応用研究センター | |
金沢大学環日本海域環境研究センター = Institute of Nature and Environmental Technology, Kanazawa University, Japan |
日本地球化学会 = Geochemical Society of Japan |