Researchers discover new fault in earthquake-prone Southern California

Scientists announced the discovery of a new fault line in Southern California in a study published this week. The newly mapped Salton Trough Fault runs parallel to the San Andreas Fault, bordering the eastern edge of the Salton Sea in the Colorado Desert.

The fault's discovery -- detailed in the journal Bulletin of the Seismological Society of America -- may force seismologists to rethink models of the San Andreas Fault system, as well as earthquake risk assessment models for the greater Los Angeles region.

The land surrounding the southern segment of the San Andreas Fault, including Southern California's Imperial and Coachella Valleys, is one of the world's most earthquake-prone regions.

"To aid in accurately assessing seismic hazard and reducing risk in a tectonically active region, it is crucial to correctly identify and locate faults before earthquakes happen," lead study study author Valerie Sahakian said in a news release.

Now a postdoctoral fellow at the U.S. Geological Survey's Earthquake Science Center, Sahakian is a graduate of the Scripps Institution of Oceanography at the University of California, San Diego.

The positioning of the new fault along the edge of the Salton Sea made it difficult to image, but researchers managed to created a detailed map of the geological deformation using seismic data as well as lidar, laser-powered surveying technology.

"We employed the marine seismic equipment to define the deformation patterns beneath the sea that constrained the location of the fault," explained Scripps geologist Neal Driscoll.

Additional research is needed to understand the new fault's relationship with the San Andreas Fault and the structural risks it poses. Early analysis suggests the Salton Trough Fault has assumed some of the strain placed on the San Andreas Fault over the last several decades.

The fault's discovery comes on the heels of a string of 200 small earthquakes, which shook the Colorado Desert last week -- raising fears that the rumbling could set off a much larger earthquake.