ダウンロード数: 66
このアイテムのファイル:
ファイル | 記述 | サイズ | フォーマット | |
---|---|---|---|---|
j.nimb.2018.12.023.pdf | 514.9 kB | Adobe PDF | 見る/開く |
タイトル: | Groundwater flow traced by bomb pulses of ³⁶Cl and tritiogenic ³He in a borehole |
著者: | Mahara, Yasunori Ohta, Tomoko |
著者名の別形: | 馬原, 保典 |
キーワード: | Global fallout Bomb pulse ³⁶Cl ³H Tri³He Piston flow |
発行日: | 15-Sep-2019 |
出版者: | Elsevier B.V. |
誌名: | Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms |
巻: | 455 |
開始ページ: | 140 |
終了ページ: | 145 |
抄録: | In 2001, a borehole was drilled to 400 m depth below the ground surface of a tableland in northern Japan, where horizontal porous sedimentary rock strata are deposited. Fresh drill-core and groundwater samples were collected from the borehole for estimating global fallout bomb pulses of ³H, which becomes tritiogenic ³He (tri³He) through β-decay, and ³⁶Cl. In the northern hemisphere, the maximum fallout deposition of ³⁶Cl from nuclear testing was observed during 1954–1957, and that of ³H in 1963. Most ³H (half-life 12.3 y) in the rock porewater had decayed to tri³He during the 38 years between 1963 and 2001. In the borehole, bomb pulses were observed in profiles of tri³He and ³⁶Cl/Cl at 101 m and around 138 m depth below the ground surface, respectively. The downward groundwater velocity was estimated to be 2.9–3.1 m/y from the depth of the ³⁶Cl/Cl bomb pulse and 2.7 m/y from the depth of the tri³He bomb pulse. Although the two velocity estimates differ by 10–15%, it is possible to model groundwater flow in the tableland as downward piston flow without diffusion. |
著作権等: | © 2018. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/ The full-text file will be made open to the public on 15 September 2021 in accordance with publisher's 'Terms and Conditions for Self-Archiving'. この論文は出版社版でありません。引用の際には出版社版をご確認ご利用ください。 This is not the published version. Please cite only the published version. |
URI: | http://hdl.handle.net/2433/243002 |
DOI(出版社版): | 10.1016/j.nimb.2018.12.023 |
出現コレクション: | 馬原 保典 |
このリポジトリに保管されているアイテムはすべて著作権により保護されています。