DOI: 10.1016/j.epsl.2020.116620
论文题名: Triggered crustal earthquake swarm across subduction segment boundary after the 2016 Pedernales, Ecuador megathrust earthquake
作者: Hoskins M.C. ; Meltzer A. ; Font Y. ; Agurto-Detzel H. ; Vaca S. ; Rolandone F. ; Nocquet J.-M. ; Soto-Cordero L. ; Stachnik J.C. ; Beck S. ; Lynner C. ; Ruiz M. ; Alvarado A. ; Hernandez S. ; Charvis P. ; Regnier M. ; Leon-Rios S. ; Rietbrock A.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2021
卷: 553 语种: 英语
中文关键词: aftershocks
; earthquake swarm
; megathrust rupture
; postseismic deformation
; triggered seismicity
; upper plate deformation
英文关键词: 3D modeling
; Deformation
; Diffusion in liquids
; Earthquake effects
; Flow of fluids
; Time series
; Coulomb stress changes
; Crustal earthquakes
; Earthquake location
; Megathrust earthquakes
; Moment tensor solutions
; Postseismic deformation
; Shallow seismicity
; Strike-slip motion
; Fault slips
; aftershock
; crustal structure
; deformation
; earthquake swarm
; plate tectonics
; postseismic process
; rupture
; segmentation
; subduction
; thrust
; trigger mechanism
; Ecuador
英文摘要: Megathrust ruptures and the ensuing postseismic deformation cause stress changes that may induce seismicity on upper plate crustal faults far from the coseismic rupture area. In this study, we analyze seismic swarms that occurred in the north Ecuador area of Esmeraldas, beginning two months after the 2016 Mw 7.8 Pedernales, Ecuador megathrust earthquake. The Esmeraldas region is 70 km from the Pedernales rupture area in a separate segment of the subduction zone. We characterize the Esmeraldas sequence, relocating the events using manual arrival time picks and a local a-priori 3D velocity model. The earthquake locations from the Esmeraldas sequence outline an upper plate fault or shear zone. The sequence contains one major swarm and several smaller swarms. Moment tensor solutions of several events include normal and strike-slip motion and non-double-couple components. During the main swarm, earthquake hypocenters increase in distance from the first event over time, at a rate of a few hundred meters per day, consistent with fluid diffusion. Events with similar waveforms occur within the sequence, and a transient is seen in time series of nearby GPS stations concurrent with the seismicity. The events with similar waveforms and the transient in GPS time series suggest that slow aseismic slip took place along a crustal normal fault during the sequence. Coulomb stress calculations show a positive Coulomb stress change in the Esmeraldas region, consistent with seismicity being triggered by the Pedernales mainshock and large aftershocks. The characteristics of the seismicity indicate that postseismic deformation involving fluid flow and slow slip activated upper plate faults in the Esmeraldas area. These findings suggest the need for further investigation into the seismic hazard potential of shallow upper plate faults and the potential for megathrust earthquakes to trigger slow-slip and shallow seismicity across separate segments of subduction zones. © 2020 The Authors Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/165515
Appears in Collections: 气候变化与战略
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作者单位: Department of Earth and Environmental Sciences, Lehigh University, 9A STEPS Bldg. 1 W. Packer Ave., Bethlehem, PA 18015, United States; Université Côte d'Azur IRD, CRNS, Observatoire de la Côte d'Azur, Géoazur, UMR, Valbonne, 7329, France; Instituto Geofísico at the Escuela Politécnica Nacional, Av. Ladrón de Guevara E11-253, Quito, 170525, Ecuador; Sorbonne Université, CNRS-INSU, Institut des Sciences de la Terre Paris, ISTeP, UMR 7193, Paris, France; Department of Geosciences, University of Arizona, 1040 E. 4th St., Tucson, AZ 85721, United States; Department of Earth Sciences, University of Delaware, 255 Academy St., Newark, DE 19716, United States; Geophysical Institute (GPI), Karlsruhe Institute of Technology, Karlsruhe, 76187, Germany
Recommended Citation:
Hoskins M.C.,Meltzer A.,Font Y.,et al. Triggered crustal earthquake swarm across subduction segment boundary after the 2016 Pedernales, Ecuador megathrust earthquake[J]. Earth and Planetary Science Letters,2021-01-01,553