'The Big One' is coming, but when? Study suggests major CA earthquake could hit sooner than later

A new study suggests the risk of "The Big One" in California could be greater than previously believed, raising concerns about the potential for widespread damage across Southern California.

Scientists have long warned of the threat posed by the San Andreas Fault, which seismologists say is capable of producing some of the state's largest earthquakes. A simulation developed in 2008 modeled a magnitude 7.8 rupture along the fault, producing nearly two minutes of shaking.

"It is the longest fault in California and therefore capable of the biggest earthquakes," said Dr. Lucy Jones, a seismologist at Caltech who helped develop the scenario.

The simulation projects hundreds of deaths and billions of dollars in damage if such an earthquake were to occur.

"We know how it'll happen. We know what the shaking will be, and that's what these models are showing that if we run these, this is the best science put together," Jones said.

Jones compared the scenario to the powerful earthquake that struck Venezuela in June.

"It's the same type of what's called a transform fault," Jones said. "It began west of Caracas and then ruptured towards Caracas, therefore helping focus energy into the heavily populated areas. We think that'll happen here as well."

Despite decades of research, earthquakes remain unpredictable.

"It could go another 100 years. It could be tomorrow. It could be, you know, next minute," Jones said.

The new study found that stress levels along parts of Southern California's fault system may be higher than previously understood.

"What we've found now is that, you know, we haven't had an earthquake in Southern California since 1857, so stresses are naturally high, and they're actually in some places, the highest that we've seen in all of these 1,000 years," said Liliane Burkhard, a geophysicist at the University of Bern.

Researchers said a significant earthquake at Cajon Pass, where the San Andreas and San Jacinto faults meet, could damage critical infrastructure across several cities.

"Aqueducts actually cross the San Andreas Fault, and if something happens, you might not have water for a while," Burkhard said.

California has spent decades preparing for major earthquakes through mandatory building retrofits and updates to building codes. However, Jones said the consequences of a major quake could extend beyond physical damage.

"We underestimate the social disruption and the economic disruption. We are so focused on our fear of dying, that we forget to be afraid of being bankrupted," Jones said.

Experts continue to encourage residents to prepare for future earthquakes by retrofitting their homes, maintaining emergency supplies and establishing communication plans.

Jones said taking immediate protective action during an earthquake can save lives.

"If you use those few seconds to get under a strong table, you now can at least get dug back out. So we say drop, cover, hold on, and it really is the safest thing to do," she said.

CNN contributed to this report.