气候变化领域集成服务门户(CCPortal): Influence of Shear Heating and Thermomechanical Coupling on Earthquake Sequences and the Brittle-Ductile Transition

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DOI	10.1029/2020JB021394
	Influence of Shear Heating and Thermomechanical Coupling on Earthquake Sequences and the Brittle-Ductile Transition
	Allison K.L.; Dunham E.M.
发表日期	2021
ISSN	21699313
卷号	126 期号:6
英文摘要	Localized frictional sliding on faults in the continental crust transitions at depth to distributed deformation in viscous shear zones. This brittle-ductile transition (BDT), and/or the transition from velocity-weakening (VW) to velocity-strengthening (VS) friction, are controlled by the lithospheric thermal structure and composition. Here, we investigate these transitions, and their effect on the depth extent of earthquakes, using 2D antiplane shear simulations of a strike-slip fault with rate-and-state friction. The off-fault material is viscoelastic, with temperature-dependent dislocation creep. We solve the heat equation for temperature, accounting for frictional and viscous shear heating that creates a thermal anomaly relative to the ambient geotherm which reduces viscosity and facilitates viscous flow. We explore several geotherms and effective normal stress distributions (by changing pore pressure), quantifying the thermal anomaly, seismic and aseismic slip, and the transition from frictional sliding to viscous flow. The thermal anomaly can reach several hundred degrees below the seismogenic zone in models with hydrostatic pressure but is smaller for higher pressure (and these high-pressure models are most consistent with San Andreas Fault heat flow constraints). Shear heating raises the BDT, sometimes to where it limits rupture depth rather than the frictional VW-to-VS transition. Our thermomechanical modeling framework can be used to evaluate lithospheric rheology and thermal models through predictions of earthquake ruptures, postseismic and interseismic crustal deformation, heat flow, and the geological structures that reflect the complex deformation beneath faults. © 2021. American Geophysical Union. All Rights Reserved.
英文关键词	earthquake cycle; shear heating; shear zone; strike-slip; viscoelasticity
语种	英语
来源期刊	Journal of Geophysical Research: Solid Earth
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/187086
作者单位	Department of Geophysics, Stanford University, Stanford, CA, United States; Now at Department of Geology, University of Maryland, College Park, MD, United States; Institute for Computational and Mathematical Engineering, Stanford University, Stanford, CA, United States
推荐引用方式 GB/T 7714	Allison K.L.,Dunham E.M.. Influence of Shear Heating and Thermomechanical Coupling on Earthquake Sequences and the Brittle-Ductile Transition[J],2021,126(6).
APA	Allison K.L.,&Dunham E.M..(2021).Influence of Shear Heating and Thermomechanical Coupling on Earthquake Sequences and the Brittle-Ductile Transition.Journal of Geophysical Research: Solid Earth,126(6).
MLA	Allison K.L.,et al."Influence of Shear Heating and Thermomechanical Coupling on Earthquake Sequences and the Brittle-Ductile Transition".Journal of Geophysical Research: Solid Earth 126.6(2021).