Tsunami generation: strain accumulation in crust and diversity of earthquake rupture process

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K04021
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 17040:Solid earth sciences-related
• Research Institution: National Research Institute for Earth Science and Disaster Prevention
• Principal Investigator: Saito Tatsuhiko 国立研究開発法人防災科学技術研究所, 地震津波防災研究部門, 主任研究員 (30550933)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 地震 / 津波

Outline of Final Research Achievements

This study investigates tsunami generation based on the tsunami theory including earthquake generation mechanism to assess where and how large tsunamis possibly occur in the future off the Pacific coast of Japan. In order to identify mechanically locked areas along the plate interface as tsunami source, we developed a method to analyze crustal deformation and applied it to the Nankai trough subduction zone. Furthermore, using a theory of energy balance associated with earthquake fault motions, we simulated the earthquake rupture and tsunami propagation. This study developed a method to create earthquake and tsunami scenarios that may occur in the future based on mechanics and observed data.

Free Research Field

固体地球物理学

Academic Significance and Societal Importance of the Research Achievements

過去の大地震が将来も繰り返して起こるとことを前提にする現在主流の地震発生の長期予測手法は，過去に発生事例が知られていない大地震の発生を想定することが難しい．本研究では，GPSなどの衛星測位技術を使うことで列島の変形を計測し，プレート境界に加わっている力を推定し，その力を原動力として巨大地震の断層破壊をシミュレートする手法の研究開発を行った．本研究によって，断層物理学と観測データをから将来起こりうる巨大地震とその津波を想定するフレームワークを実際に提示することができた．