Fault roughness and strength heterogeneity control earthquake size and stress drop

Handle URI:
http://hdl.handle.net/10754/623763
Title:
Fault roughness and strength heterogeneity control earthquake size and stress drop
Authors:
Zielke, Olaf ( 0000-0002-4797-0034 ) ; Galis, Martin ( 0000-0002-5375-7061 ) ; Mai, Paul Martin ( 0000-0002-9744-4964 )
Abstract:
An earthquake's stress drop is related to the frictional breakdown during sliding and constitutes a fundamental quantity of the rupture process. High-speed laboratory friction experiments that emulate the rupture process imply stress drop values that greatly exceed those commonly reported for natural earthquakes. We hypothesize that this stress drop discrepancy is due to fault-surface roughness and strength heterogeneity: an earthquake's moment release and its recurrence probability depend not only on stress drop and rupture dimension but also on the geometric roughness of the ruptured fault and the location of failing strength asperities along it. Using large-scale numerical simulations for earthquake ruptures under varying roughness and strength conditions, we verify our hypothesis, showing that smoother faults may generate larger earthquakes than rougher faults under identical tectonic loading conditions. We further discuss the potential impact of fault roughness on earthquake recurrence probability. This finding provides important information, also for seismic hazard analysis.
KAUST Department:
Earth Science and Engineering Program
Citation:
Zielke O, Galis M, Mai PM (2017) Fault roughness and strength heterogeneity control earthquake size and stress drop. Geophysical Research Letters 44: 777–783. Available: http://dx.doi.org/10.1002/2016gl071700.
Publisher:
Wiley-Blackwell
Journal:
Geophysical Research Letters
Issue Date:
13-Jan-2017
DOI:
10.1002/2016gl071700
Type:
Article
ISSN:
0094-8276
Sponsors:
The research reported in this publication was supported by funding from King Abdullah University of Science and Technology (KAUST). Numerical simulations for this study were carried out on the SHAHEEN II supercomputer at KAUST. Figures in the main manuscript and the online supporting information provide all the data used in this investigation. Raw data (of on-fault slip distributions) and computer codes used in this study are available from the corresponding author upon reasonable request. No financial or other types of conflicts of interest exist for the authors regarding this manuscript. We want to thank the Editor and reviewers for their construction criticism and helpful comments that improved this study.
Additional Links:
http://onlinelibrary.wiley.com/doi/10.1002/2016GL071700/full
Appears in Collections:
Articles; Earth Science and Engineering Program

Full metadata record

DC FieldValue Language
dc.contributor.authorZielke, Olafen
dc.contributor.authorGalis, Martinen
dc.contributor.authorMai, Paul Martinen
dc.date.accessioned2017-05-31T10:09:30Z-
dc.date.available2017-05-31T10:09:30Z-
dc.date.issued2017-01-13en
dc.identifier.citationZielke O, Galis M, Mai PM (2017) Fault roughness and strength heterogeneity control earthquake size and stress drop. Geophysical Research Letters 44: 777–783. Available: http://dx.doi.org/10.1002/2016gl071700.en
dc.identifier.issn0094-8276en
dc.identifier.doi10.1002/2016gl071700en
dc.identifier.urihttp://hdl.handle.net/10754/623763-
dc.description.abstractAn earthquake's stress drop is related to the frictional breakdown during sliding and constitutes a fundamental quantity of the rupture process. High-speed laboratory friction experiments that emulate the rupture process imply stress drop values that greatly exceed those commonly reported for natural earthquakes. We hypothesize that this stress drop discrepancy is due to fault-surface roughness and strength heterogeneity: an earthquake's moment release and its recurrence probability depend not only on stress drop and rupture dimension but also on the geometric roughness of the ruptured fault and the location of failing strength asperities along it. Using large-scale numerical simulations for earthquake ruptures under varying roughness and strength conditions, we verify our hypothesis, showing that smoother faults may generate larger earthquakes than rougher faults under identical tectonic loading conditions. We further discuss the potential impact of fault roughness on earthquake recurrence probability. This finding provides important information, also for seismic hazard analysis.en
dc.description.sponsorshipThe research reported in this publication was supported by funding from King Abdullah University of Science and Technology (KAUST). Numerical simulations for this study were carried out on the SHAHEEN II supercomputer at KAUST. Figures in the main manuscript and the online supporting information provide all the data used in this investigation. Raw data (of on-fault slip distributions) and computer codes used in this study are available from the corresponding author upon reasonable request. No financial or other types of conflicts of interest exist for the authors regarding this manuscript. We want to thank the Editor and reviewers for their construction criticism and helpful comments that improved this study.en
dc.publisherWiley-Blackwellen
dc.relation.urlhttp://onlinelibrary.wiley.com/doi/10.1002/2016GL071700/fullen
dc.rightsThis is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commerc ial and no modifications or adaptations are made.en
dc.subjectstress dropen
dc.subjectfault strengthen
dc.subjectheterogeneityen
dc.subjectearthquake sizeen
dc.subjectearthquake recurrenceen
dc.titleFault roughness and strength heterogeneity control earthquake size and stress dropen
dc.typeArticleen
dc.contributor.departmentEarth Science and Engineering Programen
dc.identifier.journalGeophysical Research Lettersen
dc.eprint.versionPublisher's Version/PDFen
kaust.authorZielke, Olafen
kaust.authorGalis, Martinen
kaust.authorMai, Paul Martinen
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