This Earthquake Fault Could Devastate Lake Elsinore, SoCal: Report

LAKE ELSINORE, CA — While most Californians are familiar with notorious faults like the San Andreas, experts say far fewer know about the Elsinore Fault Zone — the source of Monday’s 5.2 magnitude earthquake.

Stretching 112 miles long, the Elsinore fault is part of a larger seismic area that experts fear more Southlanders should know about.

The Elsinore fault is one of the largest seismic lines in Southern California, but historically it has been "one of the quietest," according to the SoCal Earthquake Data Center.

READ MORE: CA Quake Alert System Lauded After Warning Millions: 'Well Done!'

It runs from Imperial County to the southwestern reaches of Riverside County, greatly affecting communities like Lake Elsinore and Temecula. The fault also runs through Julian in San Diego County, where Monday's earthquake struck just after 10 a.m., rattling communities from San Diego to Los Angeles and places in between, where the fault splits into other segments.

While the Laguna Salada fault — a southeastern extension of the Elsinore Fault Zone — ruptured in a magnitude 7 quake in 1892, the main trace of the Elsinore has only recorded one historical event stronger than Monday’s 5.2: a magnitude 6 earthquake in 1910 near Temescal Valley, which caused little damage and left no known surface rupture, according to the data center.

Aside from Monday, the fault has been "quiet" for quite some time, but that dormancy is not one to be underestimated, experts say. The fault line is capable of unleashing a magnitude 7.8 earthquake, seismologist Lucy Jones told the Los Angeles Times.

The Elsinore fault is one of the major risks in Southern California,” Jones told the newspaper.

The U.S. Geological Survey published a hypothetical scenario of a 7.8 earthquake erupting along the Elsinore fault zone that could bring "violent shaking" to Southern California, including Lake Elsinore, Temecula, Wildomar, Murrieta, Corona, Chino Hills, El Monte, La Habra and East Los Angeles.

A temblor of that magnitude could throw buildings off their foundations and devastate communities, according to the scenario. The destruction would be felt over large swaths of the Southland. Meanwhile, "very strong" shaking would be felt in the surrounding areas like Rancho Cucamonga, Fontana, San Bernardino, the Orange County coast, the South Bay, the San Fernando Valley and more.

An earthquake of this size has not occurred in modern memory. The Southland's last 7.8 temblor struck in 1857 along the San Andreas.

Monday's quake was a reminder of the long-dormant Elsinore fault's capabilities and the risk of the Big One. Kate Scharer, a research geologist with the U.S. Geological Survey, warned the Times of the risk of a Big One erupting along the Elsinore fault zone.

“There’s some risk that it could be the next one,” she said. “We focus so much on the San Andreas, but we have this whole suite of active faults that are accumulating strain.”