A new catalog of southern California earthquakes, 1800-2005

Yan Y. Kagan, David D. Jackson, & Yufang Rong

Published 2006, SCEC Contribution #931

We created a new catalog of earthquakes M >= 4.7 for southern California using historical and instrumental catalogs. We did this in part to provide a resource for constructing and retrospective testing earthquake forecast models in the "Regional Earthquake Likelihood Models" (RELM) project of the Southern California Earthquake Center (SCEC). We assessed the accuracy of location, magnitude, and focal mechanism by comparing several modern earthquake catalogs (see http://scec.ess.ucla.edu/~ykagan/RELM_index.html). For older events the focal mechanisms are obtained either from the fault rupture pattern for historical earthquakes, or through solution search for the early instrumental era, or by interpolating neighboring known solutions. For each event we estimate the fault and auxiliary planes, with a probability of correct assignment. The new catalog has two parts: a point-source catalog describing the hypocentral coordinates and average moment tensor of each event, and an "extended source" catalog that represents large events (M >= 6.5) using multiple dislocations. The new catalog should allow us more insight in stress triggering investigations and calculations of earthquake hazard.

Key Words
san andreas fault, 1989 loma prieta, moment-tensor solutions, global seismicity, source parameters, focal mechanisms, geodetic data, reevaluation, aftershocks, terrascope

Citation
Kagan, Y. Y., Jackson, D. D., & Rong, Y. (2006). A new catalog of southern California earthquakes, 1800-2005. Seismological Research Letters, 77(1), 30-38.