2022 Fiscal Year Final Research Report
Comparison of timing of subduction zone earthquakes and inland earthquakes
Project/Area Number |
20K14561
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Research Category |
Grant-in-Aid for Early-Career Scientists
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Allocation Type | Multi-year Fund |
Review Section |
Basic Section 17030:Human geosciences-related
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Research Institution | Tohoku University |
Principal Investigator |
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Project Period (FY) |
2020-04-01 – 2023-03-31
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Keywords | 津波堆積物 / 活断層 / 放射性炭素年代 |
Outline of Final Research Achievements |
Subduction zone earthquake activity may also affect the surrounding stress field, which in turn may trigger inland earthquakes. For example, an inland earthquake occurred in Fukushima Prefecture immediately after the 2011 Tohoku-oki earthquake. However, since subduction zone earthquakes occur with a frequency of several hundred to a thousand years, which is beyond the range of observational records available, it is not fully understood how inland seismic activity has been affected by past subduction zone earthquakes. In this study, we precisely estimated the ages of several geological records of past earthquakes and tsunamis in the Tohoku region and compared the timing of their occurrence.
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Free Research Field |
堆積学,第四紀学,年代学
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Academic Significance and Societal Importance of the Research Achievements |
本研究では多点数の放射性炭素年代測定に基づく高精度年代推定法を用いて、東北地方の古地震痕跡(例えば、津波堆積物、活断層、噴砂)の年代についてベイズ推定を活用した統計解析により高精度での年代推定を行った。その結果、東北地方の陸域に残された古地震・古津波痕跡を網羅的に集約し、地震・津波について複数のプロキシの年代から、その同時性等を議論できた。これらの情報は、当該地域の古地震履歴を議論する上で有益なものであると考えられる。
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