Statistical Analysis of the Preparatory Phase of the Mw8.1 Iquique Earthquake, Chile
Author(s)
Aden‐Antóniow, F.
Satriano, C.
Bernard, P.
Poiata, N.
Aissaoui, E.‐M.
Vilotte, J.‐P.
Frank, W. B.
Date Issued
May 2020
Journal
Journal of Geophysical Research: Solid Earth
Publisher
American Geophysical Union (AGU)
Citation
Aden-Antóniow, F. et al. "Statistical analysis of the preparatory phase of the Mw 8.1 Iquique earthquake, Chile." Journal of Geophysical Research: Solid Earth 125, 6 (June 2020): e2019JB019337. © 2020 American Geophysical Union
Version
Final published version
Abstract
The 2014 Iquique seismic crisis in Chile, culminating with a Mw 8.1 earthquake on 1 April, highlights a complex unlocking of the Northern Chilean subduction that has been considered a seismic gap since 1877. During the year preceding this event, at least three clusters of seismic activity have been reported: in July 2013 and January and March 2014. Recent studies have proposed large-scale slab deformation as a potential trigger for the megathrust earthquake, and these clusters possibly indicate aseismic slip transients accompanying the progressive destabilization of the plate contact. However, no evidence of gradual unlocking of the interface or transient deformation has yet been found in the seismicity rate. To address this question, we develop a dense earthquake catalog covering 15 months preceding the mainshock and derived from the continuous waveform data set recorded by the Integrated Plate Boundary Observatory Chile (IPOC) and Iquique Local Network (ILN) networks. After declustering the seismicity, a space-time analysis highlights a large-scale acceleration of the seismicity along the interface accompanied by a deceleration of intermediate-depth earthquakes. We demonstrate the existence of a seismic quiescence downdip of the mainshock rupture before the July 2013 cluster. We propose that this seismic quiescence potentially highlights fluid circulation and/or aseismic motion along upper-plate crustal fault(s).
MIT Department
Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences
Terms of Use
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Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1029/2019jb019337
