Remotely triggered small earthquakes along the San Jacinto Fault Zone, CA

Jennifer M. Tarnowski, & Abhijit Ghosh

Submitted August 15, 2016, SCEC Contribution #6882, 2016 SCEC Annual Meeting Poster #239

Although there are an increasing number of studies documenting earthquakes triggered by dynamic stresses from teleseismic events, there is still much to understand about earthquake triggering on a regional scale. We focus on the central and southern San Jacinto Fault Zone (SJFZ) region, which is one of the most active fault zones in southern California. Previous studies find little evidence for earthquakes near SJFZ triggered by teleseismic events (Kane et al., 2007). However, it is not often clear what method is best to evaluate triggering for this region. We systematically examine the likelihood of remote triggering along the SJFZ using multiple methods, including the β-value statistic, temporal changes in peak magnitude, and visually scanning seismic data. We systematically examine a ten-year period with the β-value statistic, and find 25 candidate remote teleseismic earthquakes that may have triggered small quakes near SJFZ by dynamic stresses. After combining the results from all of our methods, we conservatively estimate that 14 of the 25 candidates triggered small earthquakes near the SJFZ. We find that it is difficult to use only the β-value statistic as an indicator of triggering in the San Jacinto region. However, combining it with the temporal change in peak magnitude can reveal earthquake triggering with statistically significant results.

Key Words
remote triggering, San Jacinto Fault Zone, dynamic triggering

Tarnowski, J. M., & Ghosh, A. (2016, 08). Remotely triggered small earthquakes along the San Jacinto Fault Zone, CA. Poster Presentation at 2016 SCEC Annual Meeting.

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