2016 Fiscal Year Final Research Report
Role of the Tsunami and flood deposits for strata formation in the sedimentary basin on the plate boundary, Japan.
| Project/Area Number |
26400486
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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 |
Geology
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| Research Institution | Shinshu University |
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Principal Investigator |
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| Research Collaborator |
OTA Katsuichi 信州大学, 大学院総合工学系研究科山岳地域環境科学専攻
KAKUBARI Yuri 信州大学, 大学院総合理工学系理学専攻
ICHIKAWA Yui 信州大, 大学院理工学系地球生物圏科学専攻
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| Project Period (FY) |
2014-04-01 – 2017-03-31
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| Keywords | 津波 / 洪水 / 東北沖地震津波 / 完新統 / エスチュアリー堆積物 |
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| Outline of Final Research Achievements |
The study area is situated on the Pacific coast in the Minamisouma City, Fukushima Prefecture, Northeast Japan. We took samples of the 2011 tsunami deposits from thirteen localities. We also drilled on the central part of the area and took 26 m Holocene sediments. The sandy tsunami deposits derived from the beach by the 2011 tsunami, and muddy deposits were deposited in the lagoon, which was formed by the tsunami intrusion and the subsidence of the ground. While, the Holocene estuary-fill is composed of the deposits of backshore, sandy to muddy tidal flat, subtidal estuary and salt marsh with intercalated event sand beds, and artificial fill and paddy soil in ascending order. The event sand beds yield many marine shell fragments. Radiocarbon ages indicate that the event sand layers formed approximately ever 600 years. These characters suggest the possible tsunami deposits. We also studied the flood sand layer in Nagano City, which was form by the Ninna flood in A.D. 888.
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| Free Research Field |
堆積地質学
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