--> Abstract: Unraveling the San Gorgonio Knot, California: A Three-Dimensional Numerical Investigation of San Andreas Fault Configuration through the San Gorgonio Pass, by Laura Dair and Michele Cooke; #90070 (2007)
[First Hit]

Datapages, Inc.Print this page

Unraveling the San Gorgonio Knot, California: A Three-Dimensional Numerical Investigation of San Andreas Previous HitFaultNext Hit Configuration through the San Gorgonio Pass

Laura Dair and Michele Cooke
University of Massachusetts – Geosciences Department Amherst, MA [email protected]

The San Andreas Previous HitfaultNext Hit poses significant earthquake hazards for the 24 million residents of southern California. While geologic evidence shows that the San Andreas Previous HitfaultNext Hit in the San Gorgonio knot has complex, dipping and discontinuous Previous HitfaultNext Hit strands, predictive earthquake models of this region have disregarded these complexities. We investigate alternative three-dimensional configurations of the San Andreas Previous HitfaultNext Hit through the San Gorgonio Pass to show the influence of Previous HitfaultNext Hit geometry on uplift patterns and slip rates. The different models include both a simplified vertical, continuous Previous HitfaultNext Hit and a north-dipping discontinuous Previous HitfaultNext Hit. The north-dipping model corresponds better to observations of recent uplift within the San Bernardino Mountains. The vertical Previous HitfaultNext Hit configuration has greater net slip and more efficiently transmits deformation through the San Gorgonio Pass, but the north-dipping Previous HitfaultNext Hit configuration may better match uplift patterns. There has been an ongoing debate over the slip partitioning between the Coachella Valley segment of the San Andreas and the San Jacinto Previous HitfaultNext Hit. Our study indicates that the slip portioning between the two faults has less of an effect on the slip rates and deformation than Previous HitfaultNext Hit geometry.

Fieldwork in this area has been invaluable to the creation of a realistic present day Previous HitfaultNext Hit configuration; the more geologically accurate the initial configuration the more accurate the prediction of earthquake hazards. Further study of this area will incorporate secondary faults in an attempt to understand the Previous HitfaultNext Hit evolution and provide greater insight into future hazards along the San Andreas Previous HitfaultNext Hit.

PICTURES:

DSCN8986 - Laura Dair, Previous HitfaultNext Hit at top dipping shallowly toward right side of picture (north)

DSCN9004 – Laura Dair extinct strand of the San Andreas Previous HitfaultNext Hit (straight line)

DCSN9006 – Laura Dair and Jon Matti (USGS) same stand of San Andreas

DSCN9015 – Laura Dair and Jon Matti looking at the Previous HitfaultTop deformation zone

 

AAPG Search and Discovery Article #90070 © 2007 AAPG Foundation Grants in Aid