气候变化领域集成服务门户(CCPortal): Off-Fault Damage Characterization During and After Experimental Quasi-Static and Dynamic Rupture in Crustal Rock From Laboratory P Wave Tomography and Microstructures

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DOI	10.1029/2020JB019860
	Off-Fault Damage Characterization During and After Experimental Quasi-Static and Dynamic Rupture in Crustal Rock From Laboratory P Wave Tomography and Microstructures
	Aben F.M.; Brantut N.; Mitchell T.M.
发表日期	2020
ISSN	21699313
卷号	125 期号:8
英文摘要	Elastic strain energy released during shear failure in rock is partially spent as fracture energy Γ to propagate the rupture further. Γ is dissipated within the rupture tip process zone, and includes energy dissipated as off-fault damage, Γoff. Quantifying off-fault damage formed during rupture is crucial to understand its effect on rupture dynamics and slip-weakening processes behind the rupture tip, and its contribution to seismic radiation. Here, we quantify Γoff and associated change in off-fault mechanical properties during and after quasi-static and dynamic rupture. We do so by performing dynamic and quasi-static shear failure experiments on intact Lanhélin granite under triaxial conditions. We quantify the change in elastic moduli around the fault from time-resolved 3-D P wave velocity tomography obtained during and after failure. We measure the off-fault microfracture damage after failure. From the tomography, we observe a localized maximum 25% drop in P wave velocity around the shear failure interface for both quasi-static and dynamic failure. Microfracture density data reveal a damage zone width of around 10 mm after quasi-static failure, and 20 mm after dynamic failure. Microfracture densities obtained from P wave velocity tomography models using an effective medium approach are in good agreement with the measured off-fault microfracture damage. Γoff obtained from off-fault microfracture measurements is around 3 kJ m2 for quasi-static rupture, and 5.5 kJ m2 for dynamic rupture. We argue that rupture velocity determines damage zone width for slip up to a few mm, and that shear fracture energy Γ increases with increasing rupture velocity. ©2020. The Authors.
英文关键词	earthquake energy budget; fault damage zone; fracture energy; laboratory tomography; shear rupture
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/187653
作者单位	Department of Earth Sciences, University College London, London, United Kingdom
推荐引用方式 GB/T 7714	Aben F.M.,Brantut N.,Mitchell T.M.. Off-Fault Damage Characterization During and After Experimental Quasi-Static and Dynamic Rupture in Crustal Rock From Laboratory P Wave Tomography and Microstructures[J],2020,125(8).
APA	Aben F.M.,Brantut N.,&Mitchell T.M..(2020).Off-Fault Damage Characterization During and After Experimental Quasi-Static and Dynamic Rupture in Crustal Rock From Laboratory P Wave Tomography and Microstructures.Journal of Geophysical Research: Solid Earth,125(8).
MLA	Aben F.M.,et al."Off-Fault Damage Characterization During and After Experimental Quasi-Static and Dynamic Rupture in Crustal Rock From Laboratory P Wave Tomography and Microstructures".Journal of Geophysical Research: Solid Earth 125.8(2020).