Student Field Trip: The Enigmatic San Gorgonio Pass

September 13, 2009

San Gorgonio Pass
Palm Springs, CA

This trip will visit sites in the San Gorgonio Pass region where the San Andreas fault appears to disaggregate into a family of irregular and discontinuous right-lateral, reverse, thrust, and oblique-normal faults. Seismological studies also show that crustal deformation here is broadly distributed, primarily on strike-slip and thrust faults at depths of ~5-20 km. Deformation along the San Andreas fault zone in this region sharply contrasts regions to the northwest and southeast where deformation is restricted to a much narrower zone. Despite this complexity, ages of paleoseismic earthquakes from the Pass overlap with records in the Mojave and Coachella Valley regions in support of the controversial notion that a very large earthquake can rupture an ~ 300-km-long segment of the San Andreas fault. This 'worst-case scenario earthquake' facing southern California provided the basis for the Great Southern California ShakeOut Exercise of November 2008.

Space is limited to 60 students. Register through the 2009 SCEC Annual Meeting website.

Download: Field Trip Guide (6.6 MB PDF)

For more information, contact: Doug Yule, Mike Oskin