Will 2016 Kumamto Earthquake triger caldera eruption of Aso volcano ?
| Project/Area Number |
18K03803
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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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| Project Period (FY) |
2018-04-01 – 2022-03-31
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| Project Status |
Completed (Fiscal Year 2021)
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| Budget Amount *help |
¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000)
Fiscal Year 2020: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2019: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2018: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
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| Keywords | 阿蘇カルデラ / 熊本地震 / マグマ溜まり / 地震波速度構造 / 地殻変動 / トモグラフィー / レシーバ関数 / 低速度領域 / レシーバー関数解析 / GNSS / InSAR / マグマだまり / 地震波干渉法 / 地殻構造 / 阿蘇火山 / レシーバー関数 |
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| Outline of Final Research Achievements |
Seismic travel-time tomography and surface wave tomography were performed to geophysically detect the magma accumulation process in the crust and the transfer of magma to the surface during the preparation process of a caldera eruption of the Aso volcano. Then, the effects of the fault movement of the 2016 Kumamoto earthquake on magma accumulation were evaluated by a finite element analysis. The results show that the fault movement of the Kumamoto earthquake caused only a 0.06% increase in the volume of the magma chamber of the Aso volcano. This small amount of change is considered insufficient to trigger a medium-sized eruption (VUI2 or higher). Seismic wave velocity structure analysis based on receiver function analysis did not detect changes in the velocity structure of the low-velocity layer in the lower crust before and after the Kumamoto earthquake.
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| Academic Significance and Societal Importance of the Research Achievements |
大地震の発生後に付近の火山活動が活発化することが知られている。2016年熊本地震の直後に、阿蘇火山でごく小規模な発生し、半年後には小規模なマグマ水蒸気噴火が発生した。そこで、熊本地震の断層運動が、阿蘇火山のマグマ供給系に及ぼした影響を評価したところ、本震の断層運動では、巨大なカルデラ噴火をトリガーするには不十分だったことが明らかになった。また、カルデラ噴火の準備過程に関連する地殻深部の地震波速度構造も変化していないことが明らかになった。
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Report
(5 results)
Research Products
(3 results)
