Aseismic slip and seismogenic coupling along the central San Andreas Fault

Romain Jolivet, Mark Simons, Piyush S. Agram, Zacharie Duputel, & Zheng-Kang Shen

Published January 22, 2015, SCEC Contribution #1975

We use high resolution SAR and GPS-derived observations of surface displacements to derive the first probabilistic estimates of fault coupling in the region of the San Andreas Fault creeping section using a fully Bayesian approach. The unequaled resolution enabled by this approach allows us to infer a high probability of significant elastic strain build up along the creeping section, in between the terminations of the 1857 and 1906 magnitude 7.9 earthquakes. We isolate discreet locked asperities, consistent with evidence for magnitude 6+ earthquakes over the past century in this area, in particular during the initiation phase of the 1857 earthquake. As creeping segments may be related to the initiation, propagation and termination of seismic ruptures, such distribution of locked and creeping asperities highlights the central role of the creeping section on the occurrence of major earthquakes along the San Andreas Fault.

Key Words
Seismic cycle related deformations, Tectonic deformation, Satellite geodesy:results, Inverse theory, Rheology and friction of fault zones

Jolivet, R., Simons, M., Agram, P. S., Duputel, Z., & Shen, Z. (2015). Aseismic slip and seismogenic coupling along the central San Andreas Fault. Geophysical Research Letters, 42(2), 297-306. doi: 10.1002/2014GL062222.

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