Fault strength and rupture process controlled by fault surface topography

Shiqing Xu1,2; Eiichi Fukuyama2,3; Futoshi Yamashita 2; Hironori Kawakata2,4; Kazuo Mizoguchi2,5; Shigeru Takizawa2

2023-01-02

10.1038/s41561-022-01093-z

Nature Geoscience   影响因子和分区

1752-0894

1752-0908

Faults are rarely completely smooth, with topographic undulations coming from the distribution of asperities along the fault surface. Understanding the effects of fault surface topography on fault strength and earthquake source properties has been limited due to a lack of in situ observations in the field. Here we use simulated earthquake cycles on metre-scale laboratory faults to show the effects of the degree of fault topographic heterogeneity, especially on macroscopic peak strength represented by the shear force required to commence macroscopic failure. Our results demonstrate that the less heterogeneous fault is weaker, due to its lower macroscopic peak strength, and produces a larger stress drop on average than the more heterogeneous fault. Rupture along the less heterogeneous fault tends to propagate at subshear speed while the more heterogeneous fault accommodates a wider range of rupture speeds, including slow slip and supershear rupture. These results reveal how fault topographic heterogeneity affects macroscopic peak strength at rupture initiation and stress drop during rupture propagation, which has important implications for understanding natural faults and earthquakes.

SCI

英语

NI论文 ; ESI高被引

第一 ; 通讯

JSPS KAKENHI["JP17H02954","JP16H06477"] ; NSFC[42074048] ; National Key R&D Program of China[2021YFC3000700]

Geology

Geosciences, Multidisciplinary

WOS:000906626300001

NATURE PORTFOLIO

人工提交

1.Department of Earth and Space Sciences, Southern University of Science and Technology, Shenzhen, China.
2.National Research Institute for Earth Science and Disaster Resilience, Tsukuba, Japan.
3.Department of Civil and Earth Resources Engineering, Kyoto University, Kyoto, Japan.
4.College of Science and Engineering, Ritsumeikan University, Kusatsu, Japan.
5.Central Research Institute of Electric Power Industry, Abiko, Japan.

Shiqing Xu,Eiichi Fukuyama,Futoshi Yamashita ,et al. Fault strength and rupture process controlled by fault surface topography[J]. Nature Geoscience,2023,16(1):94–100.

Shiqing Xu,Eiichi Fukuyama,Futoshi Yamashita ,Hironori Kawakata,Kazuo Mizoguchi,&Shigeru Takizawa.(2023).Fault strength and rupture process controlled by fault surface topography.Nature Geoscience,16(1),94–100.

Shiqing Xu,et al."Fault strength and rupture process controlled by fault surface topography".Nature Geoscience 16.1(2023):94–100.