Connecting the San Andreas Fault through Southern California

A web of faults links the San Andreas Fault over a discontinuous 80-kilometer [50 mile] region in southern California. Carena et al. analyzed a gap in the famous fault line that runs from the Mojave Desert to the Coachella Valley and suggest that a network of seismically active faults likely connects the two strands of the 1,200-kilometer [750-mile] San Andreas Fault.

The researchers examined the three-dimensional geometry of the fault system in the complex region, reaching nearly 20 kilometers [10 miles] below the Earth’s surface. They report that the San Andreas devolves into a series of faults with varying configurations such that it would require an unlikely sequence of fault ruptures to trigger a massive earthquake involving both strands of the fault.

The authors also modeled several possible fault rupture scenarios for earthquakes in the Los Angeles area to determine the likelihood of a complex rupture.

Title: Lack of continuity of the San Andreas Fault in southern California: Three-dimensional fault models and earthquake scenarios