气候变化领域集成服务门户(CCPortal): Seismic swarms produced by rapid fluid injection into a low permeability laboratory fault

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DOI	10.1016/j.epsl.2020.116726
	Seismic swarms produced by rapid fluid injection into a low permeability laboratory fault
	Cebry S.B.L.; McLaskey G.C.
发表日期	2021
ISSN	0012821X
卷号	557
英文摘要	Fluid injection, from activities such wastewater disposal, hydraulic stimulation, or enhanced geothermal systems, decreases effective normal stress on faults and promotes slip. Earthquake nucleation models suggest the slip at low effective normal stress will be stable and aseismic—contrary to observed increases in seismicity that are often attributed to fluid injection. We conducted laboratory experiments using a biaxial loading apparatus that demonstrate how an increase in fluid pressure can induce “stick-slip” events along a preexisting saw-cut fault in a poly(methyl methacrylate) (PMMA) sample. We compared slip events generated by externally squeezing the sample (shear-triggered) to those due to direct fluid injection (fluid-triggered) and studied the effects of injection rate and stress levels. Shear-triggered slip events began on a localized nucleation patch and slip smoothly accelerated from slow and aseismic to fast and seismic. Fluid-triggered slip events initiated far more abruptly and were associated with swarms of tiny foreshocks. These foreshocks were able to bypass the smooth nucleation process and jump-start a mainshock resulting in an abrupt initiation. Analysis of these foreshocks indicates that the rapid injection of fluid into a low permeability fault promotes heterogeneous stress and strength which can cause many events to initiate—some of which grow large. We conclude that while a reduction in effective normal stress stabilizes fault slip, rapid fluid injection into a low permeability fault increases multi-scale stress/strength heterogeneities which can initiate small seismic events that have the potential to grow rapidly, even into low stress regions. © 2020 Elsevier B.V.
关键词	earthquake initiation fluid injection foreshock heterogeneity induced seismicity laboratory experiments
英文关键词	Crystallization; Earthquakes; Esters; Geothermal fields; Nucleation; Shear flow; Slip forming; Stick-slip; Transport properties; Wastewater disposal; Earthquake nucleation; Effective normal stress; Enhanced geothermal systems; Hydraulic stimulations; Laboratory experiments; Low stress region; Nucleation process; Poly(methyl methacrylate) (PMMA); Fault slips; earthquake mechanism; earthquake swarm; experimental study; fault zone; fluid injection; geothermal system; heterogeneity; hydraulic fracturing; induced seismicity; permeability
语种	英语
来源期刊	Earth and Planetary Science Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/203047
作者单位	School of Civil and Environmental Engineering, Cornell University, Ithaca, NY, United States
推荐引用方式 GB/T 7714	Cebry S.B.L.,McLaskey G.C.. Seismic swarms produced by rapid fluid injection into a low permeability laboratory fault[J],2021,557.
APA	Cebry S.B.L.,&McLaskey G.C..(2021).Seismic swarms produced by rapid fluid injection into a low permeability laboratory fault.Earth and Planetary Science Letters,557.
MLA	Cebry S.B.L.,et al."Seismic swarms produced by rapid fluid injection into a low permeability laboratory fault".Earth and Planetary Science Letters 557(2021).