2022 Fiscal Year Final Research Report
Study on plastic strain that appears depending on the stress history in crustal deformation
| Project/Area Number |
19K04017
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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 | Kyoto University |
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Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
鷺谷 威 名古屋大学, 減災連携研究センター, 教授 (50362299)
MenesesーGutierrez Angela (MenesesーGutierrezAngelaDelValle) 名古屋大学, 高等研究院(減災連携), 特任助教 (90846099)
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| Project Period (FY) |
2019-04-01 – 2023-03-31
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| Keywords | 塑性歪み / 非弾性歪み / 歪み速度場 / GNSS / 歪み速度パラドックス / 東北地方太平洋沖地震 |
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| Outline of Final Research Achievements |
Crustal deformation is generally considered to consist of elastic, viscous, and plastic strain. Observed geodetic data contain all of these components, and their separation has been an important issue. In this study, we succeeded in estimating each of these components separately for the first time, by analyzing GNSS data before and after the Tohoku-oki earthquake in the northern part of the Niigata-Kobe tectonic zone. This result that indicates plastic strain appeared before the Tohoku-Oki earthquake is an important piece to solve the strain-rate paradox in Japan.
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| Free Research Field |
固体地球物理学
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| Academic Significance and Societal Importance of the Research Achievements |
日本列島では活発な地殻変動が生じているが，その原因については分かっていない部分も多い．本研究は，複合的な要因で生じる地殻変動について，弾性・粘性・塑性の３つの成分に分離し推定することによって，その原因の解明に向けて理解を大きく前進させた．特に，これまであまり注目されて来なかった塑性歪み速度を定量的に推定したのは，恐らく世界で初めてである．地震発生やその予測の高度化，あるいは地形形成過程の理解増進などに寄与する基礎的研究と位置付けられる．
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