Towards inferring earthquake patterns from geodetic observations of interseismic coupling
Abstract
Ultimately, seismotectonic studies seek to provide ways of assessing the timing, magnitude and spatial extent of future earthquakes. Ample observations document the spatial variability in interseismic coupling, defined as a degree of locking of a fault during the period of stress build-up between seismic events: fully or nearly locked fault patches are often surrounded by aseismically creeping areas. However, it is unclear how these observations could help assess future earthquakes. Here we simulate spontaneous seismic and aseismic fault slip with a fully dynamic numerical model. Our simulations establish the dependence of earthquake rupture patterns and interseismic coupling on spatial variations of fault friction. We consider the long-term evolution of slip on a model fault where two seismogenic, locked segments are separated by an aseismically slipping patch where rupture is impeded. We find that the probability for a large earthquake to break through the rupture-impeding patch is correlated with the interseismic coupling averaged over this patch. In addition, the probability that an earthquake breaks through the rupture-impeding patch and interseismic coupling are both related to fault friction properties through a single non-dimensional parameter. Our study opens the possibility of predicting seismic rupture patterns that a fault system can produce on the basis of observations of its interseismic coupling, and suggests that regions of low interseismic coupling may reveal permanent barriers to large earthquakes.
Additional Information
© 2010 Macmillan Publishers Limited. Received 10 February 2010; accepted 18 March 2010; published online 25 April 2010. This study was supported by the National Science Foundation (grant EAR 0548277) and Caltech Tectonics Observatory. This is Caltech Tectonics Observatory contribution no 130. Numerical simulations for this study were carried out on the CITerra Dell cluster at the Division of Geological and Planetary Sciences of the California Institute of Technology. Author contributions: Y.K. designed the study, carried out and analysed the numerical experiments and wrote the paper. J-P.A. and N.L. analysed the numerical experiments and contributed to the concept development. All authors discussed the results and commented on the paper.Attached Files
Supplemental Material - ngeo843-s1.pdf
Supplemental Material - ngeo843-s2.mov
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Additional details
- Eprint ID
- 18442
- Resolver ID
- CaltechAUTHORS:20100526-075511174
- EAR-0548277
- NSF
- Caltech Tectonics Observatory
- Created
-
2010-06-07Created from EPrint's datestamp field
- Updated
-
2021-11-08Created from EPrint's last_modified field
- Caltech groups
- Caltech Tectonics Observatory, Seismological Laboratory, Division of Geological and Planetary Sciences
- Other Numbering System Name
- Caltech Tectonics Observatory
- Other Numbering System Identifier
- 130