| 研究課題/領域番号 |
21K03739
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| 研究機関 | 東京大学 |
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研究代表者 |
Snyder Glen 東京大学, 大気海洋研究所, 特任研究員 (90751777)
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| 研究分担者 |
柿崎 喜宏 東京大学, 大学院理学系研究科(理学部), 特任研究員 (20570633) [辞退]
白石 史人 広島大学, 先進理工系科学研究科(理), 准教授 (30626908)
松本 良 明治大学, 研究・知財戦略機構(生田), 研究推進員(客員研究員) (40011762)
戸丸 仁 千葉大学, 大学院理学研究院, 准教授 (80588244)
高畑 直人 東京大学, 大気海洋研究所, 助教 (90345059)
伊地知 雄太 東京大学, 大学院理学系研究科(理学部), 特任研究員 (10911258)
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| 研究期間 (年度) |
2021-04-01 – 2024-03-31
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| キーワード | gas hydrate / cold seep / noble gas isotopes / helium / argon / stable isotopes / dolomite / calcite |
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| 研究実績の概要 |
Analyses were carried out on both gas hydrate microdolomite inclusions and methane derived carbonates.Using the data, we were able to derive a model for radiogenic helium-4 production within the two types of carbonate and determine quantitative differences between gases trapped in seep-related carbonates from Joetsu Basin, offshore Niigata,and Tatar Trough in the northern part of Japan Sea. We also determined the stable isotopic composition of the carbonates to compare with that of the carbon dioxide in the inclusions. The mineralogy of the carbonates was determined through X-ray diffaction.At the Mobara seep sites of Chiba Prefecture microcrystalline carbonates were not recovered but were able to determine the noble gas and stable isotopic composition of the bubbling gases.
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
3: やや遅れている
理由
We currently have one paper in press:Shiraishi, F., Akimoto, T., Tomioka, N., Takahashi, Y., Matsumoto, R. and Snyder, G.T. (2023) Microbial traces found in microdolomite associated with seep-related shallow gas hydrate, Front. Earth Sci. Sec. Biogeoscience,11, DOI: 10.3389/feart.2023.1188142 In order to promote outreach with our research, we proposed an action plan for the UN Decade of Ocean Science: "Project COESS: Chemistry, Observation, and Ecology of Submarine Seeps" which was endorsed by UNESCO in September, 2022. Impurities in the carbonates have made it difficult to carry out analysis of stable Mg-isotopes. Despite progress in both analytical and geochemical modelling of our research, we were also unable to coordinate a time to do Field work in Hokkaido and Niigata during 2022.
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| 今後の研究の推進方策 |
Both Snyder (PI) and Shiraishi (co-PI) have seep-related talks at the 2023 JpGU meeting. A final field sampling effort will be carried out, either in Niigata in the Joetsu Basin area, or in Hokkaido near the seeps there. In addition, Snyder is currently guest associate editor of a Frontiers in Earth Science research theme on cold seeps and hydrothermal vents. The following manuscript is in preparation for the journal volume: Snyder et al. "Novel use of noble gas and stable isotope analyses of gas inclusions in authigenic carbonates to reveal past seep activity: A comparison of samples from Tatar Strait, Russia; Joetsu Basin, Japan; and Brejo do Espinho, Brazil." We still have a few samples which we must analyze for noble gas isotopes and stable isotopes before the manuscript is completed.
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| 次年度使用額が生じた理由 |
The amount to be used next year is planned for Open-Access Publication fees. The manuscript, which we planned to complete during the past fiscal year is still in preparation and will be submitted to an international journal in coming months.
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| 備考 |
Snyder is currently Guest Associate Editor for Frontiers in Earth Science Research Topic.
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