DOI: 10.1016/j.epsl.2018.02.042
Scopus记录号: 2-s2.0-85044444522
论文题名: A viscoplastic shear-zone model for deep (15–50 km) slow-slip events at plate convergent margins
作者: Yin A. ; Xie Z. ; Meng L.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2018
卷: 491 起始页码: 81
结束页码: 94
语种: 英语
英文关键词: convergent margins
; slow-slip events
; viscoplasticity
; viscosity
Scopus关键词: Friction
; Locks (fasteners)
; Viscoplasticity
; Viscosity
; Characteristic velocities
; Coefficient of frictions
; Convergent margin
; Laboratory experiments
; Mechanical behavior
; Plastic failure
; Slow slip events
; Strengthening mechanisms
; Shear flow
; convergent margin
; friction
; plate convergence
; plate motion
; shear zone
; slip
; subduction zone
; viscoelasticity
; viscosity
英文摘要: A key issue in understanding the physics of deep (15–50 km) slow-slip events (D-SSE) at plate convergent margins is how their initially unstable motion becomes stabilized. Here we address this issue by quantifying a rate-strengthening mechanism using a viscoplastic shear-zone model inspired by recent advances in field observations and laboratory experiments. The well-established segmentation of slip modes in the downdip direction of a subduction shear zone allows discretization of an interseismic forearc system into the (1) frontal segment bounded by an interseismically locked megathrust, (2) middle segment bounded by episodically locked and unlocked viscoplastic shear zone, and (3) interior segment that slips freely. The three segments are assumed to be linked laterally by two springs that tighten with time, and the increasing elastic stress due to spring tightening eventually leads to plastic failure and initial viscous shear. This simplification leads to seven key model parameters that dictate a wide range of mechanical behaviors of an idealized convergent margin. Specifically, the viscoplastic rheology requires the initially unstable sliding to be terminated nearly instantaneously at a characteristic velocity, which is followed by stable sliding (i.e., slow-slip). The characteristic velocity, which is on the order of <10−7 m/s for the convergent margins examined in this study, depends on the (1) effective coefficient of friction, (2) thickness, (3) depth, and (4) viscosity of the viscoplastic shear zone. As viscosity decreases exponentially with temperature, our model predicts faster slow-slip rates, shorter slow-slip durations, more frequent slow-slip occurrences, and larger slow-slip magnitudes at warmer convergent margins. © 2018 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/109926
Appears in Collections: 影响、适应和脆弱性 气候变化事实与影响
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作者单位: Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles, CA 90095-156702, United States
Recommended Citation:
Yin A.,Xie Z.,Meng L.. A viscoplastic shear-zone model for deep (15–50 km) slow-slip events at plate convergent margins[J]. Earth and Planetary Science Letters,2018-01-01,491