2021 Fiscal Year Final Research Report
Quasi-realtime detection of basal melting of the Greenland Ice Sheet by seismological methods
| Project/Area Number |
18K03794
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Review Section |
Basic Section 17040:Solid earth sciences-related
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| Research Institution | Tohoku University |
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Principal Investigator |
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| Project Period (FY) |
2018-04-01 – 2022-03-31
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| Keywords | グリーンランド / 地震波トモグラフィー / 地震波形解析 / ホットプルーム / 地殻 / マントル |
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| Outline of Final Research Achievements |
In Greenland, located in the Arctic, a steady seismic network had not been deployed for a long time due to the harsh environment on the ice sheet. In this study, we analyze the seismic waveform and P-wave arrival-time data obtained by the newly established seismic network "GLISN", and revealed for the first time the 3-D crust and mantle structure beneath this area, as well as the seismic attenuation (Q factor) of the entire ice sheet. The main achievement is the discovery of a hot mantle plume rising from the core-mantle boundary to the mantle transition zone beneath Greenland, named "Greenland Plume", which may be a heat source for basal melting of the ice sheet and active volcanoes distributed along the Mid-Atlantic Ridge. A series of our achievements have been published as four international papers.
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| Free Research Field |
地震学
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| Academic Significance and Societal Importance of the Research Achievements |
グリーンランドとその周辺地域では，氷床の底部融解やスバールバル諸島西部の特異的な高地殻熱流量，大西洋中央海嶺に沿った活発な火山活動といった現象が知られていたが，これらの間の関連は不明であった．本課題の一連の研究によって，これらはグリーンランドプルームとその支流の活動として統一的に説明が可能となった．特に氷床の底部融解に伴う海水準変動や火山活動よる環境変化は我々の生活とも密接に関わる問題であり，その根源となるメカニズムを提唱したことは学術的・社会的意義が極めて大きい．
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