Fault strength of the plate interface along the northeastern Japan Arc inferred from tectonic loading model and inversion alayisis

2018 Fiscal Year Final Research Report

• Project/Area Number: 26400451
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Solid earth and planetary physics
• Research Institution: Nagoya University
• Principal Investigator: Terakawa Toshiko 名古屋大学, 環境学研究科, 准教授 (30451826)
• Research Collaborator: Hashimoto Chihiro
• Project Period (FY): 2014-04-01 – 2019-03-31
• Keywords: 絶対応力場 / 応力インバージョン / 誤差推定

Outline of Final Research Achievements

I developed a method to model and estimate the absolute stress field from earthquake focal mechanism solutions using a single parameter of pore fluid pressures, based on the Bayesian statistical inference. In this method we can obtain 6 components of a stress tensor, which enables us to evaluate temporal changes in various kinds of physical quantities following large events. Especially, it is important to estimate the absolute stress level, based on the temporal change in elastic strain energy. I also proposed a method to evaluate the estimation errors for a stress inversion method.

Free Research Field

地震学

Academic Significance and Societal Importance of the Research Achievements

地震は、地殻やマントル内に蓄えられた応力を断層運動によって一気に解放する物理過程である。しかし，応力は直接測ることの難しい量であり，地殻にどれくらいの応力が働いているのかは４０年以上にわたって論争の対象となってきた．本研究は，地震発生の物理を考慮し，地震データからベイズの統計推論に基づいて，地殻の絶対応力レベルを推定したものである．