Accuracy improvement of earthquake history of the Nankai Trough by sediment records from terminal basins

2017 Fiscal Year Final Research Report

• Project/Area Number: 15H02988
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Natural disaster / Disaster prevention science
• Research Institution: The University of Tokyo
• Principal Investigator: Ashi Juichiro 東京大学, 大学院新領域創成科学研究科, 准教授 (40251409)
• Co-Investigator(Kenkyū-buntansha): 池原 研 国立研究開発法人産業技術総合研究所, 地質調査総合センター, 首席研究員 (40356423) ; 辻 健 九州大学, 工学研究院, 教授 (60455491)
• Co-Investigator(Renkei-kenkyūsha): IRINO Tomohisa 北海道大学, 地球環境科学研究科(研究院), 助教 (70332476) ; YAMAGUCHI Asuka 東京大学, 大気海洋研究所, 准教授 (30570634) ; OMURA Akiko 東京大学, 大学院新領域創成科学研究科, 日本学術振興会特別研究員 (80401298)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: タービダイト / 地すべり / 混濁流 / 堆積盆

Outline of Final Research Achievements

We conducted shallow subbottom profiling survey and sediment core sampling in the Nankai forearc region to know the earthquake history from off Tokai to off Hyuga. A subbottom profiler on a remotely operated vehicle successfully obtained high-resolution shallow subseafloor structures from the trench landward slope to the forearc basin, and found active faults and on-going tilting off Cape Muroto and off Hyuga. Sedimentological study revealed rework and redeposition processes of surface sediments by earthquake shaking and suggested that the thickness of the redeposited layer could correlate with the depth of the reworked unit of the source formation.

Free Research Field

海洋地質学