A Transient in Surface Motions Dominated by Deep Afterslip Subsequent to a Shallow Supershear Earthquake

The 2018 Mw7.5 Palu Case

Journal article (2021)

Authors

N. Nijholt , Physical and Space Geodesy - CEG
J. Efendi Efendi Geospatial Information Agency
D. A. Sarsito Institute of Technology Bandung
R.E.M. Riva Physical and Space Geodesy - CEG
Copyright: © 2021 N. Nijholt, W.J.F. Simons, J. Efendi, D. A. Sarsito, R.E.M. Riva
DOI: https://doi.org/10.1029/2020GC009491
More Info
expand_more

Published Date

2021

Language

English

Reuse Rights

Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.

Abstract

The 2018 (Formula presented.) Palu earthquake is a remarkable strike-slip event due to its nature as a shallow supershear fault rupture across several segments and a destructive tsunami that followed coseismic deformation. GPS offsets in the wake of the 2018 earthquake display a transient in the surface motions of northwest Sulawesi. A Bayesian approach identifies (predominantly aseismic) deep afterslip on and below the coseismic rupture plane as the dominant physical mechanism causing the cumulative, postseismic, surface displacements whereas viscous relaxation of the lower crust and poro-elastic rebound contribute negligibly. We confirm a correlation between shallow supershear rupture and postseismic surface transients with afterslip activity in the zone below an interseismically locked fault plane where the slip rate tapers from zero to creeping.

Files

2020GC009491.pdf
(pdf | 3.18 Mb)
Unknown license