Teleseismic dynamic triggering of microearthquakes in the Anza area, California: the role of dynamic strain and pore pressure

Wenyuan Fan, Andrew J. Barbour, & Elizabeth S. Cochran

Published August 14, 2019, SCEC Contribution #9627, 2019 SCEC Annual Meeting Poster #081

Teleseismic dynamic triggering has been reported for various fault systems. These dynamically triggered earthquakes are thought to be caused directly by the increasing dynamic stress due to passing seismic waves, or indirectly by transient reductions in fault strength. These two competing hypotheses have not been systematically evaluated together due to the general lack of high resolution earthquake catalogs in regions with in-situ strain and pore fluid pressure measurements. Here we take advantage of the newly developed Quake Template Matching (QTM) catalog in Southern California to systematically evaluate teleseismic dynamic triggering patterns in the Anza area, where dense strainmeter and pore pressure sensing systems are colocated as part of the Plate Boundary Observatory borehole network. Using events identified as triggering events, we present a comparative investigation of the spectra of durations of root-mean-squared strains and pore-pressures in hopes of gaining improved understanding of the physical mechanisms of the temporally evolving seismicity in Southern California.

Key Words
Dynamic tirggering, Anza, Strainmeter, Pore pressure

Citation
Fan, W., Barbour, A. J., & Cochran, E. S. (2019, 08). Teleseismic dynamic triggering of microearthquakes in the Anza area, California: the role of dynamic strain and pore pressure. Poster Presentation at 2019 SCEC Annual Meeting.

Related Projects & Working Groups
Seismology