Tsunami trace survey on the Bonin Islands for revealing recurrence history of great earthquakes in the Izu-Bonin subduction zone
Project/Area Number |
26750129
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Research Category |
Grant-in-Aid for Young Scientists (B)
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Allocation Type | Multi-year Fund |
Research Field |
Natural disaster / Disaster prevention science
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Research Institution | The University of Tokyo |
Principal Investigator |
Harada Tomoya 東京大学, 地震研究所, 特任助教 (30452501)
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Project Period (FY) |
2014-04-01 – 2017-03-31
|
Project Status |
Completed (Fiscal Year 2016)
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Budget Amount *help |
¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000)
Fiscal Year 2015: ¥2,340,000 (Direct Cost: ¥1,800,000、Indirect Cost: ¥540,000)
Fiscal Year 2014: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
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Keywords | 津波堆積物 / 津波石 / 津波痕跡調査 / 小笠原諸島 / 伊豆-小笠原海溝 / 巨大地震 / 1605年慶長地震 / 小笠原諸島父島 / 二見港周辺 / 津波堆積物調査 / 九十九里海岸 / 八丈島 / 八重根遺跡 / 1782年津波 / 年代測定 |
Outline of Final Research Achievements |
The Izu-Bonin subduction zone has been regarded as so-called ”Mariana-type subduction zone” where M>7 interplate earthquakes did not occur inherently. Ishibashi and Harada (2013) and Harada et al. (2013) proposed a hypothesis that the 1605 Keicho earthquake was a giant/great earthquake along in the Izu-Bonin subduction zone from re-examination of historical documents and tsunami numerical simulation. In order to confirm their hypothesis, we performed tsunami trace survey on the Bonin Islands. As a result, we discovered more than 3 tsunami deposit layers at the Sakai-ura beach and 4-5 tsunami deposit layers at the river mouth of the Yatsuse River in the Chichi Island. C14 dating shows these layers deposited in 17-18 A.D. However, we could not identify the 1605 tsunami deposit from these layers due to the dating accuracy.
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Report
(4 results)
Research Products
(1 results)