Ridgecrest residents inspect a recent fault rupture following two large earthquakes in the area on July 7, 2019, near Ridgecrest, California.

No one can predict with certainty when the next massive earthquake— aka “The Big One”—will rock Southern California. But new research suggests it might be sooner than we previously  thought. Disaster-preparedness experts worry that Californians are underprepared for a colossal quake, particularly when it comes to insurance.

“Because large earthquakes don’t happen very frequently, many people don’t think about them often or fully comprehend the risks,” says Glenn Pomeroy, CEO of the California Earthquake Authority (CEA), the state’s biggest provider of residential earthquake insurance.

Pomeroy notes that most Californians live within 30 miles of one of the state’s more than 500 active faults, including those that have been newly unearthed. With nearly 40 million residents, California ranks as the most populated state in the country.

“The biggest obstacle can be yourself” when it comes to earthquake preparedness, says Jason Ballmann, communications manager at the Southern California Earthquake Center.

The Threat Has Been Recalculated

According to a study published last October by geophysicists at Caltech and NASA’s Jet Propulsion Laboratory, the last significant earthquakes in the state were Southern California’s twin Ridgecrest quakes in July 2019. The quakes exposed a “web” of 20 previously undiscovered small earthquake faults that contributed to the Ridgecrest event.

In addition, the 6.4-magnitude and 7.1-magnitude Ridgecrest quakes and more than 100 aftershocks strained the nearby Garlock Fault.

When the study was released, Zachary Ross, assistant professor of geophysics at the California Institute of Technology and the study’s lead author, issued this warning: “We can’t just assume that the largest faults dominate the seismic hazard if many smaller faults can link up to create these major quakes.”

Translation: The threat of The Big One might be bigger than anyone imagined.

Little Faults

As Ross and his colleagues explained, major earthquakes are commonly thought to be triggered by the rupture of one long fault, like the roughly 800-mile San Andreas Fault, and not by a network of faults.

Because the Ridgecrest quakes—which shook a remote desert area of Southern California, causing little damage and no deaths—increased stress on the Garlock Fault, that fault is now about 100 times more likely to cause a large quake than before the Ridgecrest quakes. That’s according to a study published in July in the Bulletin of the Seismological Society of America.

Due to the connection between the Garlock Fault and the San Andreas Fault, the study suggests a 50-50 chance that a Garlock quake within 30 miles of the San Andreas would lead to a quake in what’s known as the Mojave segment of the San Andreas’ southern end. The study’s authors put the odds of a southern San Andreas quake happening by July 2021 at 1%.

The Los Angeles metro area borders the southern swath of the San Andreas, and the northern swath cuts through the San Francisco Bay Area. As such, millions of Californians live along a fault responsible for some of the state’s biggest earthquakes.

An Epic Disaster

Of course, all of this research doesn’t prove The Big One is imminent. But when it does occur, it promises to be an epic disaster.

Experts define The Big One as a quake of at least a 7.8 magnitude along the southern part of the San Andreas Fault. That quake would be 44 times stronger than Southern California’s Northridge earthquake of 1994, which caused 72 deaths, about 9,000 injuries and an estimated $25 billion in damage.

In 2008, a group of scientists, engineers and others predicted The Big One would lead to more than 1,800 deaths, 50,000 injuries and $200 billion in damage and other losses.

A scientific forecast released in 2014 pegged the likelihood at 48% of at least one California earthquake with a magnitude of 7.5 or more within the following 30 years. The likelihood drops to 7% for one or more quakes at 8 or higher. Broken down by region, the percentages are higher for the Los Angeles area than for the San Francisco area.

Regardless of where a huge quake might hit, experts express concern about one of the big cracks in preparedness: the low number of Californians who carry earthquake insurance. Standard renters and homeowners insurance policies don’t cover earthquakes.

In 2019, only about 14% of residential insurance policies in California were coupled with earthquake coverage, according to the state’s department of insurance. In all, more than 1.6 million earthquake policies were in effect across the state last year (through the CEA and other insurers).

Pomeroy, the California Earthquake Authority’s CEO, says his group has seen a dramatic increase in purchases of earthquake insurance since 2016. Today, the CEA insures more than 1.1 million homes and provides about two-thirds of the state’s residential earthquake coverage.

“Although earthquake insurance purchases have gone up, there is still not enough earthquake insurance penetration in California,” Pomeroy says. “Because large, damaging earthquakes don’t happen very often, many people don’t perceive the risks or take steps to be prepared.”

“That still means somewhere north of 80% of the homes in the state will not have insurance funds to make repairs after an earthquake. That’s not a good thing,” says Amy Bach, executive director of United Policyholders, a consumer advocacy group.

Not Buying It

Why don’t more California homeowners buy earthquake insurance? One significant reason: The cost. In 2019, the annual premium for residential earthquake coverage from the CEA averaged $727. For policies from other insurers, the average annual premium was $874.

On top of that, the deductible for a homeowners policy from the CEA ranges anywhere from 5% to 25% of a home’s coverage amount. For example, a 5% deductible for a home covered at $500,000 would be $25,000. With that deductible, if you filed a claim to cover $80,000 in earthquake damage and it’s approved, your payout would be $55,000. That would leave the homeowner on the hook for $25,000 to fix the damage.

Because of the premiums and deductibles, Bach says that when you’re buying earthquake insurance, you’re essentially buying catastrophic coverage in case a major earthquake damages or destroys your home. Still, she adds, United Policyholders encourages people to buy earthquake insurance if they can afford it.

“We don’t talk enough about the financial implications. Hundreds of thousands of people could become immediately homeless after an earthquake in the Bay Area or Southern California,” says Ballmann of the Southern California Earthquake Center.

Getting Ready for The Big One

Aside from purchasing earthquake insurance, experts offer these recommendations for getting ready for The Big One (or any other quake, for that matter):

  • Participate in the Great ShakeOut earthquake drill, which happens annually on the third Thursday of October. The 2020 drill will be at 10:15 a.m. Oct. 15, with organizers expecting a lot of folks to join virtually this year. Last year’s Great ShakeOut drill in California attracted 10.8 million participants.
  • Do earthquake drills throughout the year. October isn’t the only time for drills, according to Ballmann. During a one-minute earthquake drill, you practice three safety measures. First, you immediately drop to your hands and knees. Next, you cover your head and neck, and crawl under a nearby table. Finally, you hold on until the shaking stops.
  • Download the MyShake app, which provides early warning of a California quake. The app came out in 2019. In August, Gov. Gavin Newsom announced a partnership with Google to build the early warning technology into Android phones.
  • Secure your household belongings. Ballmann recommends securing bookcases and other heavy furniture to your walls so they don’t topple over during a quake. He also suggests moving heavy objects from higher shelves to lower shelves to prevent them from turning into dangerous projectiles, and applying museum putty to the bottom of glass, porcelain and ceramic items that might break when they fall.
  • Sign up for the CEA-backed Earthquake Brace + Bolt program. The program provides eligible homeowners with $3,000 grants to offset the cost of a seismic retrofit of their house. A homeowner need not be one of the CEA’s policyholders to participate. Pomeroy says the program has enabled close to 12,000 retrofits. “We estimate that more than 1 million older houses in high-hazard areas of California are in need of a simple brace-and-bolt retrofit to help keep the house on its foundation when the ground shakes,” he says.

Concern Is Usually Short-Lived

Ballmann says that when an earthquake happens, it prompts Californians to discuss earthquake preparedness—and they might even put together disaster preparedness kits—“but earthquakes don’t necessarily motivate people to get prepared in a long-lasting, resilient fashion.”

That long-lasting preparedness should include embracing the seven-step earthquake safety plan outlined by the Earthquake Country Alliance, he says.

“Unfortunately,” Pomeroy says, “most Californians probably aren’t as prepared as they could be, given that scientists say a damaging earthquake could happen at any time.”