Earthquake! What You Need to Know About The Deadly San Jacinto Fault That Rocked California Recently

On Friday, a 5.2-magnitude earthquake rocked Southern California. While it did not cause any damages, it triggered more than 450 aftershocks that led many West Coast residents to worry.

This recent earthquake was centered on the San Jacinto fault, one of the region's most active faultlines. And because it runs through many populated areas, it poses a great risk--maybe even greater than the San Andreas fault, which is more popular.

What is the San Jacinto fault?

The San Jacinto Fault Zone runs 210 kilometers, including the Coyote Creek fault, according to the Southern California Earthquake Center of California Institute of Technology (Caltech). Nearby communities include San Bernardino. Loma Linda, San Jacinto, Lytle Creek, Anze, Hemet, Ocotillo Wells and Borrego Springs.

The epicenter of Friday's quake was near Borrego Springs.

The Los Angeles Times reported that the fault cuts into the middle of the Inland Empire, which means it can affect more people if ever it moves and ruptures.

San Bernardino, in particular, is a major concern as it reportedly has the largest concentration of brick buildings that are very vulnerable and high risk during earthquakes.

Southern California at risk?

In the same report in the Times, Caltech research professor for geophysics Egill Hauksson said most earthquakes felt in Southern California are on the San Jacinto fault.

In 1987, the Superstition Hills earthquake hit east of San Diego with magnitudes of 6.5 and 6.7 It cost $3 million in property damages, according to the U.S. Geological Survey.

With the growing population in the areas on the San Jacinto Fault Zone, a future earthquake of that magnitude can cause even more severe damages.

Big One prediction?

But a study released earlier this year revealed an even more terrifying scenario: a possible 7.5-magnitude earthquake if both the San Andreas and San Jacinto faults rupture together.

The study by Stanford researchers revealed that the deadly 7.5-magnitude earthquake that hit Southern California in December 1812 was most probably caused by the slippage of San Andreas that triggered the second fault, which was San Jacinto.

It showed that with the rupture of multiple faults, more powerful temblors and damages are possible.

Julian Lozon, the author of the study, said their research shows that the San Jacinto fault also plays an important role, as it can influence the San Andreas fault, which cause stronger earthquakes but lesser damages since it is situated in more isolated areas.

Published in the journal Science Advances, the study can boost our understanding of earthquakes and be better prepared and equipped should a Big One come our way. It can not only improve earthquake models, but also awareness among people.

"People shouldn't just be thinking about the San Andreas Fault," Lozos said.