Slip rate on the San Diego trough fault zone, inner California Borderland, and the 1986 Oceanside earthquake swarm revisited

Bulletin of the Seismological Society of America
By: , and 

Links

Abstract

The San Diego trough fault zone (SDTFZ) is part of a 90-km-wide zone of faults within the inner California Borderland that accommodates motion between the Pacific and North American plates. Along with most faults offshore southern California, the slip rate and paleoseismic history of the SDTFZ are unknown. We present new seismic reflection data that show that the fault zone steps across a 5-km-wide stepover to continue for an additional 60 km north of its previously mapped extent. The 1986 Oceanside earthquake swarm is located within the 20-km-long restraining stepover. Farther north, at the latitude of Santa Catalina Island, the SDTFZ bends 20° to the west and may be linked via a complex zone of folds with the San Pedro basin fault zone (SPBFZ). In a cooperative program between the U.S. Geological Survey (USGS) and the Monterey Bay Aquarium Research Institute (MBARI), we measure and date the coseismic offset of a submarine channel that intersects the fault zone near the SDTFZ–SPBFZ junction. We estimate a horizontal slip rate of about 1:5  0:3 mm=yr over the past 12,270 yr.

Study Area

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Slip rate on the San Diego trough fault zone, inner California Borderland, and the 1986 Oceanside earthquake swarm revisited
Series title Bulletin of the Seismological Society of America
DOI 10.1785/0120110317
Volume 102
Issue 6
Year Published 2012
Language English
Publisher Seismological Society of America
Contributing office(s) Pacific Coastal and Marine Science Center
Description 13 p.
First page 2300
Last page 2312
Country United States
State California
Other Geospatial San Diego trough fault zone
Online Only (Y/N) N
Additional Online Files (Y/N) N