Communication Between the Northern and Southern Central San Andreas Fault via Dynamically Triggered Creep

Brenton Hirao, Heather Savage, & Emily E. Brodsky

Published June 29, 2021, SCEC Contribution #11022

The interaction between creep events and earthquakes at the regional scale has implications for earthquake cycles, yet few examples of such interaction have been found on continental faults. We report shallow triggered creep along the northern edge of the central creeping section of the San Andreas fault following the 2003 San Simeon Mw 6.5 and 2004 Parkfield Mw 6.0 earthquakes. Following both earthquakes, we observe a delayed creep event beginning at depth on a strainmeter and continuing on a nearby creepmeter. In addition, between the regional earthquakes, the average slip rate at one creepmeter increased from 10 mm/yr to 30 mm/yr, and returned to 10 mm/yr after the Parkfield earthquake. Creep events and creep rate changes indicate that triggering connects behavior in the northern San Andreas fault to the southern section and other regional faults.

Citation
Hirao, B., Savage, H., & Brodsky, E. E. (2021). Communication Between the Northern and Southern Central San Andreas Fault via Dynamically Triggered Creep. Geophysical Research Letters, 48(13). doi: 10.1029/2021GL092530.