Two slip regimes in sheared granular fault

Zhang，Yahui1; Gao，Ke1; Li，Changdong2,3

2023-04-15

10.1016/j.epsl.2023.118086

EARTH AND PLANETARY SCIENCE LETTERS   Impact Factor & Quartile

0012-821X

1385-013X

In the stick-slip cycles of faults, the evolving contact state inside the gouge is a major contribution to the evolution of fault friction. However, the microscopic contact changes within stick-slip cycles associated with the possible existence of multiple fault slip regimes are still obscure. By simulating a sheared fault containing a granular gouge, we examine the particle-level contact evolution inside the gouge and the corresponding gouge stress field heterogeneity at fault slip. We find two regimes of fault slip driven by the heterogeneity of the gouge stress field: in the case of weak gouge stress field heterogeneity, local contact rearrangements give rise to macroscopic friction coefficient drop and accumulated gouge stress field heterogeneity (dispersive regime); in the instance of strong stress field heterogeneity, catastrophic failure occurs via contact rearrangement sweeping the whole fault and homogenizes the stress field distribution in the gouge (pervasive regime). In the language of self-organized criticality, the accumulation of gouge stress field heterogeneity is an inevitable consequence of increased entropy in the preparation stage of a large earthquake, which eventually destroys the long-range stress field correlations in the gouge and resets at the beginning of a new cycle of a large earthquake.

coordination number gouge stress heterogeneity particle-level contact evolution sheared granular gouge stick-slip

SCI

English

NI Journal Papers

First ; Corresponding

National Key R&D Program of China[2022YFF0800601] ; National Natural Science Fund for Major Programs of China[42090054] ; National Natu- ral Science Fund for Excellent Young Scholars of China[41922055]

Geochemistry & Geophysics

Geochemistry & Geophysics

WOS:000961945100001

ELSEVIER

GEOSCIENCES

2-s2.0-85149438771

Scopus

1.Department of Earth and Space Sciences,Southern University of Science and Technology,Shenzhen,Guangdong,518055,China
2.Faculty of Engineering,China University of Geosciences,Wuhan,Hubei,430074,China
3.Badong National Observation and Research Station of Geohazards,China University of Geosciences,Wuhan,430074,China

Zhang，Yahui,Gao，Ke,Li，Changdong. Two slip regimes in sheared granular fault[J]. EARTH AND PLANETARY SCIENCE LETTERS,2023,608.

Zhang，Yahui,Gao，Ke,&Li，Changdong.(2023).Two slip regimes in sheared granular fault.EARTH AND PLANETARY SCIENCE LETTERS,608.

Zhang，Yahui,et al."Two slip regimes in sheared granular fault".EARTH AND PLANETARY SCIENCE LETTERS 608(2023).