Experimental research on the transient rheology of rocks for the understanding of post-seismic deformation of the Tohoku Oki Earthquake

2016 Fiscal Year Final Research Report

• Project/Area Number: 26287123
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Geology
• Research Institution: Tohoku University
• Principal Investigator: Muto Jun 東北大学, 理学(系)研究科(研究院), 准教授 (40545787)
• Co-Investigator(Kenkyū-buntansha): 飯沼 卓史 国立研究開発法人海洋研究開発機構, 地震津波海域観測研究開発センター, 研究員 (10436074) ; 平賀 岳彦 東京大学, 地震研究所, 准教授 (10444077) ; 大園 真子 山形大学, 理学部, 講師 (10623837)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 東北沖地震 / レオロジー / 余効変動 / 粘弾性緩和 / 余効すべり / 上部マントル / 下部地殻

Outline of Final Research Achievements

The objective of the study is to conduct deformation experiments of lower crust and upper mantle rocks to illuminate their rheological properties predicting the postseismic deformation of the Tohoku-oki earthquake. To this end, we conducted the reinvention of furnaces of a gas confining medium apparatus and improvement of the resolution of stress measurement in a solid confining medium apparatus in Tohoku University. Using those apparatuses, we conducted deformation experiments of various rocks composing of subduction zone mantle wedge and deeper portion of plate boundary, and clarified the properties of viscous flow with the special emphasis on the role of fluid. In addition, we conducted a two - dimensional analysis of the post-seismic deformation using experimentally obtained rheological properties of transient phases and constructed a heterogeneous rheology model including the transient process applicable to the postseismic deformation of the Tohoku earthquake.

Free Research Field

岩石レオロジー