| Project/Area Number |
15K13581
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| Research Category |
Grant-in-Aid for Challenging Exploratory Research
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| Allocation Type | Multi-year Fund |
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| Research Field |
Geology
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| Research Institution | National Institute of Polar Research |
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Principal Investigator |
Suganuma Yusuke 国立極地研究所, 研究教育系, 准教授 (70431898)
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| Co-Investigator(Kenkyū-buntansha) |
片岡 龍峰 国立極地研究所, 研究教育系, 准教授 (90462671)
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| Research Collaborator |
Takiguchi Syogo 東邦大学, 理学部化学科, 卒業生
Nakahara Yukina 東邦大学, 理学部化学科, 卒業生
Zondervan Albert GNS Science
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| Project Period (FY) |
2015-04-01 – 2019-03-31
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| Project Status |
Completed (Fiscal Year 2018)
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| Budget Amount *help |
¥3,770,000 (Direct Cost: ¥2,900,000、Indirect Cost: ¥870,000)
Fiscal Year 2017: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2016: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2015: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
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| Keywords | 海底堆積物 / 超新星爆発 / Be-10 / 地磁気変動 / 地磁気強度 |
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| Outline of Final Research Achievements |
The Earth’s environment has been affected by extraterrestrial events, such as mass extinctions due to the impact of a meteorite. However, there is no clear evidence of supernova event and relating the Earth’s environmental change in the geological record. In this study, we tried to detect a signature of the supernova based on cosmogenic nuclides (Be-10) analysis of the marine sediment. However, there is no clear peak of Be-10 flux in the marine sediments for the last 3 million years. This suggests that there is no significant supernova event during this interval.
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| Academic Significance and Societal Importance of the Research Achievements |
本研究では，研究対象とした過去300万年間において顕著な超新星爆発イベントの存在を示すデータは得られなかった．しかし，今回確立した手法はさらに古い時代での探査にも利用可能であり，今後の研究の進展によっては超新星爆発イベントが発見されるかもしれない．一方，宇宙線生成核種（Be-10）データのリファレンスとした地磁気逆転イベント（Matuyama-Brunhes境界）については，地磁気逆転に対応した銀河宇宙線量増大が確認された．この知見は，今後地磁気変動メカニズムについての研究を進める上で極めて重要なデータを提供するものとなる．
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