Experimental study on anisotropies of seismic velocity and resistivity under differential stresses

2016 Fiscal Year Final Research Report

• Project/Area Number: 26610140
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Solid earth and planetary physics
• Research Institution: University of Toyama
• Principal Investigator: Watanabe Tohru 富山大学, 大学院理工学研究部(理学), 教授 (30262497)
• Research Collaborator: MORIMOTO Misaki 富山大学, 理学部地球科学科 ; SAWAKI Ryo 富山大学, 理学部地球科学科 ; WATANABE Shinya 富山大学, 理学部地球科学科
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 差応力 / 異方性 / 地震波速度 / 比抵抗 / 電気伝導度 / クラック

Outline of Final Research Achievements

In order to understand anisotropies of seismic velocity and electrical conductivity under differential stress conditions, measurements of elastic wave velocities and electrical conductivity were conducted on a granitic rock under uni-axial compression. Cracks perpendicular to the compression axis are selectively closed to cause significant anisotropy of velocity. On the other hand, little anisotropy of electrical conductivity was induced by differential stresses. During uni-axial compressions, conductivity decreases similarly in the directions parallel and perpendicular to the compression axis.The conduction path in a direction must be composed of cracks of various orientations. In all directions, conductivity decreases by the closure of cracks perpendicular to the compression direction.

Free Research Field

固体地球物理学