Development of new evaluation method of fault activity by focusing electrical resistivity structure under an active fault
| Project/Area Number |
16K01319
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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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| Research Field |
Natural disaster / Disaster prevention science
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| Research Institution | Osaka City University |
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Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
村上 英記 高知大学, 教育研究部自然科学系理工学部門, 教授 (10166259)
加藤 茂弘 兵庫県立人と自然の博物館, その他部局等, 研究員(移行) (50301809)
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| Project Period (FY) |
2016-04-01 – 2019-03-31
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| Project Status |
Completed (Fiscal Year 2018)
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| Budget Amount *help |
¥4,680,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥1,080,000)
Fiscal Year 2018: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000)
Fiscal Year 2017: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000)
Fiscal Year 2016: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
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| Keywords | 電気伝導度 / 活断層 / 地磁気地電流法 / 山崎断層 / 郷村断層 / 電気伝導度構造 / 自然災害 / 活動セグメント / 断層ダメージゾーン |
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| Outline of Final Research Achievements |
In order to clarify the nature and activity of active faults, it is important to clarify the subsurface structure in addition to geological and geomorphological features. In this study, magnetotelluric surveys were made and constructed electrical resistivity models across the Gomura fault zone (Kyoto Prefecture) and the Nagisen fault zone located at the western end of the Yamazaki fault system (Hyogo prefecture / Okayama prefecture). The Gomura fault zone consists of three faults having different features in fault activity, total displacement, the latest fault activity and so on. The resistivity model across these three faults proposed the reason making these differences. The Nagisen fault zone is divided into two fault segments based on surface topography, however, the resistivity structure of them were quite similar and the result show these two fault segments should be a single fault segment.
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| Academic Significance and Societal Importance of the Research Achievements |
地表情報だけからでは未解明であった活断層の性状を電気比抵抗構造から明らかにできることを実証した．断層構造の解明には，地震波探査が広く用いられているが，西日本に広く分布する横ずれ型断層（鉛直な境界，幅のある破砕帯を持つ）では，解像力が低下する．比抵抗構造探査ではこれらの構造も解像できることを示した．また，「電気比抵抗」は「地震波速度」，「密度」とは独立した物理量であるので，新しい切り口で断層構造を描出できる，また複数の物理量の組合せから，断層構造をより厳密に描出できる．それによって，活断層の学術的研究に新しい視点を与え，また，活断層で発生する地震の規模推定の精度を大きく向上させることができる．
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Report
(4 results)
Research Products
(10 results)
