Separating rapid relocking, afterslip, and viscoelastic relaxation: An application of the postseismic straightening method to the Maule 2010 cGPS

Bedford, Jonathan, Moreno, Marcos, Li, Shaoyang, Oncken, Onno, Baez, Juan Carlos, Bevis, Michael, Heidbach, Oliver and Lange, Dietrich (2016) Separating rapid relocking, afterslip, and viscoelastic relaxation: An application of the postseismic straightening method to the Maule 2010 cGPS Journal of Geophysical Research - Solid Earth, 121 (10). pp. 7618-7638. DOI 10.1002/2016JB013093.

[img]
Preview
Text
jgrb51826-1.pdf - Published Version

Download (5Mb) | Preview

Supplementary data:

Abstract

The postseismic deformation captured with continuous Global Positioning System (cGPS) monitoring following many recent mega-thrust events has been shown to be a signal composed of two dominant processes: afterslip on the plate interface and viscoelastic relaxation of the continental and oceanic mantles in response to the coseismic stress perturbation. Following the south-central Chile 2010 Maule Mw 8.8 earthquake, the time series from the regional cGPS network show a distinct curvature in the pathway of the horizontal motion that is not easily fit by a stationary decaying pattern of afterslip in combination with viscoelastic relaxation. Here we show that with realistic assumptions about the long-term decay of the afterslip signal, the postseismic signal can be decomposed into three first-order contributing processes: plate interface re-locking, plate interface afterslip, and mantle viscoelastic relaxation. From our analyses we conclude that the plate interface recovers its interseismic locking state rapidly (model space ranges between an instant recovery and a period of 1 year); a finding that supports laboratory experimental evidence as well as some recent studies of aftershocks and postseismic surface deformation. Furthermore, re-locking is the main cause of the curvature in the cGPS signal, and this study presents a plausible range of geodetic re-locking rates following a megathrust earthquake.

Document Type: Article
Additional Information: WOS:000388441800034
Keywords: postseismic; subduction; afterslip; locking; viscoelastic; relaxation
Research affiliation: GFZ
OceanRep > GEOMAR > FB4 Dynamics of the Ocean Floor > FB4-GDY Marine Geodynamics
Refereed: Yes
DOI etc.: 10.1002/2016JB013093
ISSN: 0148-0227
Projects: PESCADOS
Date Deposited: 21 Oct 2016 12:47
Last Modified: 01 May 2017 23:38
URI: http://eprints.uni-kiel.de/id/eprint/34383

Actions (login required)

View Item View Item

Document Downloads

More statistics for this item...