Rheological transitions facilitate fault‐spanning ruptures on seismically active and creeping faults
Abstract
Physical constraints on the seismogenic potential of major fault zones may aid in improving seismic hazard assessments, but the mechanics of earthquake nucleation and rupture are obscured by the complexity that faults display. In this work, we investigate the mechanisms behind giant earthquakes by employing a microphysically based seismic cycle simulator. This microphysical approach is directly based on the mechanics of friction as inferred from laboratory tests and can explain a broad spectrum of fault slip behavior. We show that regular earthquakes are controlled by the size and distribution of (nominally) frictionally unstable asperities, whereas fault‐spanning earthquakes are governed by a rheological transition occurring in creeping fault segments. Moreover, this facilitates the nucleation of giant earthquakes on faults that are weakly seismically coupled (i.e., creeping). This microphysically based approach offers opportunities for investigating long‐term seismic cycle behavior of natural faults.
Additional Information
© 2020 American Geophysical Union. Received 31 DEC 2019; Accepted 11 JUN 2020; Accepted article online 24 JUN 2020. The authors thank two anonymous reviewers and the associate editor A. A. Gabriel for their thoughtful comments on the manuscript. M. v. d. E. thanks Å. Fagereng for sharing his views on fault zone structure. This project is supported by the European Research Council (ERC), Grant 335915, by the NWO Vidi‐Grant 854.12.001 awarded to A. R. Niemeijer, and by the French government through the UCA^(JEDI) Investments in the Future project managed by the National Research Agency (ANR) with the referencenumber ANR-15-IDEX‐01. J. P. A. acknowledges supplemental funding to NSF CAREER Grant EAR-1151926 for research opportunities in Europe. Data Availability Statement: The most recent version of the QDYN source code is publicly available at https://github.com/ydluo/qdyn; an archived version is available at https://doi.org/10.5281/zenodo.322459.Attached Files
Published - 2019JB019328.pdf
Submitted - manuscript.pdf
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Additional details
- Alternative title
- Giant earthquakes on quiet faults governed by rheological transitions
- Eprint ID
- 85723
- Resolver ID
- CaltechAUTHORS:20180410-102006492
- 335915
- European Research Council (ERC)
- 854.12.001
- Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO)
- ANR-15-IDEX-01
- Agence Nationale pour la Recherche (ANR)
- EAR-1151926
- NSF
- Created
-
2018-04-10Created from EPrint's datestamp field
- Updated
-
2023-06-01Created from EPrint's last_modified field
- Caltech groups
- Seismological Laboratory