日本地球惑星科学連合2023年大会

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[J] 口頭発表

セッション記号 S (固体地球科学) » S-CG 固体地球科学複合領域・一般

[S-CG50] 地球惑星科学におけるレオロジーと破壊・摩擦の物理

2023年5月24日(水) 09:00 〜 10:30 301B (幕張メッセ国際会議場)

コンビーナ:田阪 美樹(静岡大学 )、東 真太郎(東京工業大学 理学院 地球惑星科学系)、清水 以知子(京都大学大学院理学研究科地球惑星科学専攻)、桑野 修(国立研究開発法人 海洋研究開発機構)、座長:清水 以知子(京都大学大学院理学研究科地球惑星科学専攻)、桑野 修(国立研究開発法人 海洋研究開発機構)

09:45 〜 10:00

[SCG50-04] Simultaneous measurement of seismic velocity and electrical resistivity of mafic and ultramafic rocks during triaxial deformation under fluid-saturated condition

*Eranga Gayanath Jayawickrama1Ikuo Katayama1 (1.Hiroshima University)

キーワード:Velocity, Resistivity, Crack

Various experimental investigations have shown that cracks embedded in rocks generate a significant effect on rocks’ physical properties such as static rock moduli, elastic wave velocity, and resistivity, under both hydrostatic and differential stress conditions. However, so far, experiments designed to investigate the effect of cracks on the above properties have only been capable of investigating those properties individually or two at most in combination, at a time. While the results of such experiments enlighten the geophysical observations to a certain degree, we find that it is of utmost necessity to investigate the crack effect on the above stated properties simultaneously, since cracks affect individual physical properties differently. Therefore, using a new 16-channel feedthrough system, we performed triaxial deformation experiments at Hiroshima University on thermally cracked mafic (diabase) and ultramafic (harzburgite) rocks under fully saturated conditions while simultaneously recording the porosity evolution, stress-strain response, elastic wave velocity, and resistivity. The results indicated a remarkable agreement among the various physical properties as the crack properties, such as crack density and aspect ratio, evolved with the increasing differential stress until catastrophic failure is occurred. In addition to these results, we further discuss the strength contrast of the thermally treated diabase and harzburgite that is in analogy to the damaged layered oceanic lithosphere.