The elucidation of the nature of shallow interplate aseismic slip based on repeating earthquakes in United States and in the world

2021 Fiscal Year Final Research Report

• Project/Area Number: 17KK0081
• Research Category: Fund for the Promotion of Joint International Research (Fostering Joint International Research)
• Allocation Type: Multi-year Fund
• Research Field: Solid earth and planetary physics
• Research Institution: Tohoku University
• Principal Investigator: Uchida Naoki 東北大学, 理学研究科, 准教授 (80374908)
• Project Period (FY): 2018 – 2021
• Keywords: 小繰り返し地震 / 非地震性すべり / プレート境界地震 / スロースリップ / S-net / スロー地震

Outline of Final Research Achievements

In this international joint research, I have investigated repeating earthquakes along the San Andreas fault and around the world to estimate the distribution of aseismic slip and to investigate the role of aseismic slip in earthquake occurrences. I stayed Geological Survey Canada for two weeks in 2019 and University of California, Berkeley for 11 months in 2020-2021. As a result of the research, the anisotropic structure of offshore Tohoku was revealed (Uchida Nakajima Wang et al., Nature Communications, 2021), new repeating earthquake selection program was developed and the distribution of repeating earthquakes in California and in the world was estimated. For the latter two achievements, paper and programs are now in preparation for publication.

Free Research Field

地震学

Academic Significance and Societal Importance of the Research Achievements

プレート境界浅部は，巨大地震が発生するとともに，津波地震やスロー地震など様々なタイプの滑りが起こる．本研究ではその様な滑り過程が繰り返し地震によりある程度わかってきた東北沖と比較・検討するために，サンアンドレアス断層や世界全域で繰り返し地震活動の系統的探索を行った．本研究で開発したプログラムは世界のどこでも適用ができ，また得られた非地震性すべりの分布と時間変化は，これまで測地学的データを用いて得られた結果を補完する重要なデータとなる．