DOI: 10.1016/j.epsl.2020.116623
论文题名: Competition between preslip and deviatoric stress modulates precursors for laboratory earthquakes
作者: Shreedharan S. ; Bolton D.C. ; Rivière J. ; Marone C.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2021
卷: 553 语种: 英语
中文关键词: earthquake precursors
; elastic waves
; fault mechanics
; friction
; laboratory earthquakes
; stick-slip
英文关键词: Acoustic wave velocity
; Earthquakes
; Elastic waves
; Fault slips
; Wave propagation
; Amplitude variations
; Crustal earthquakes
; Elastic wave velocity
; In-laboratory experiments
; Inter-seismic periods
; Seismic hazard assessment
; Time-lapse monitoring
; Velocity variations
; Shear flow
; crustal structure
; earthquake precursor
; elastic wave
; fault
; friction
; seismic hazard
; stick-slip
; wave velocity
英文摘要: Variations in elastic wave velocity and amplitude prior to failure have been documented in laboratory experiments as well as in a limited number of crustal earthquakes. These variations have generally been attributed to fault zone healing, changes in crack density, or pore fluid effects modulated dilatation or fault slip. However, the relationships between amplitude and velocity variations during the seismic cycle, and the underlying mechanisms of precursors to failure remain poorly understood. Here, we perform frictional shear experiments and measure the evolution of elastic wave velocity and amplitude throughout the laboratory seismic cycle. We find that elastic amplitudes and velocities undergo clear preseismic variations prior to fault failure. While preseismic amplitude reduction occurs early in the interseismic period, wave speed reduces later, just prior to failure. We perform a complementary set of stress oscillation experiments to quantify the response of seismic amplitudes and velocities to variations in the stress tensor. Taken together, our results indicate that preseismic amplitude variations are primarily controlled by fault slip rate and acceleration. On the other hand, elastic velocity responds to a combination of fault preslip which reduces seismic wavespeed and increasing stress in the wallrock, which increases wavespeed. Our data show that precursory changes in seismic wave speed may be more common than previously thought because they are masked by changes in wallrock stress. These results underscore the importance of continuous and long-term time-lapse monitoring of crustal faults for seismic hazard assessment and potential precursors to failure. © 2020 The Authors Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/165670
Appears in Collections: 气候变化与战略
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作者单位: Dept. of Geosciences, Pennsylvania State University, University Park, PA 16802, United States; Dept. of Engineering Science and Mechanics, Pennsylvania State University, University Park, PA 16802, United States; Dipartimento di Scienze della Terra, La Sapienza Università di Roma, Italy
Recommended Citation:
Shreedharan S.,Bolton D.C.,Rivière J.,et al. Competition between preslip and deviatoric stress modulates precursors for laboratory earthquakes[J]. Earth and Planetary Science Letters,2021-01-01,553