It's the unavoidable series of questions Christine Goulet gets every time she's asked what she does for a living. "When is the next big earthquake coming? Do you know where? When should we get ready?"Goulet, director of the U.S. Geological Survey's Earthquake Science Center in Los Angeles, told USA TODAY. "It's almost without fail once they know I study earthquakes. If I received a dollar every time I'm asked, I'd be rich." Goulet has answers, but she can't predict the future. The ominous truth: The Big One could happen any time, and there's more than one possible "Big One." "It's gonna happen. An earthquake could be in a matter of minutes, the next hour, tomorrow, or in a week from now, we can't predict that precisely at this time. We don't know," Goulet said. "But the point in general is we want and need to prepare for them." 'Swaying back and forth':Magnitude 7 earthquake, aftershocks rock California The most authoritative research on the risk to California was conducted in 2015, but little has changed in the past decade. The state will almost certainly facea magnitude 6.7 or larger earthquakewithin the next three decades, the USGS concludes. Some of the most at-risk locations areSan Francisco and Los Angeles. California's continuous temblor risk coincides with a huge earthquake brewing along theCascadia Subduction Zoneoff the coast of the Pacific Northwest. Withnearly four dozen faultsin the region stretching from Napa to Monterey, the San Francisco Bay Area has a 72% chance of a major quake registering 6.7 magnitude or higher by 2043, USGS researchers previously estimated. The findings also indicate that the Bay Area has a 51% chance of experiencing an earthquake with a magnitude of 7 and a 20% chance of measuring a magnitude of 7.5 or higher within that time frame. "The earthquake threat is very real," saidRichard Allen, a professor at the University of California, Berkeley and the director of the Berkeley Seismology Lab. "It is a real challenge as we have to take that long-term view, but also not to live our lives in fear." In December, thousands in the Bay Area and across Northern California were worried after amagnitude 7 earthquakestruck along a sparsely populated northern coast of California, triggering a tsunami warning across a swath of the West Coast stretching from southern Oregon to San Francisco. Traci Grant, 53, a public relations specialist who felt the quake in San Francisco, toldUSA TODAYat the time she felt her retrofitted apartment move in slow motion. "It just kept going and going," Grant said. "It was scary and a bit exciting at the same time. It was more of a roll than just shake, shake, shake." Fragile environment:A collapsing glacier destroyed a Swiss village. Is climate change to blame? Less than two hours after the initial quake, some areas experienced 13 different aftershocks, ranging from 5.1 to 3.1, the USGS reported. Two hours after that, at least 39 aftershocks of at least a 2.5 magnitude occured in the region, authorities said. No earthquake-related injuries or major damages were reported. Goulet said if the quake had been directly on land, "the impact would've been more devastating." Goulet said December's quake magnitude conjured up theGreat San Francisco Earthquake and Fireof 1906. It was a nearly minute-long 7.9 magnitude quake followed by a fire that burned for three days, destroying thousands of buildings. The San Francisco quake killed an estimated 3,000 people and destroyed roughly 80% of the city. It is known as one of the deadliest in U.S. history. Allen also noted the 1868 Hayward Fault earthquake that struck the heart of the Bay Area and killed 30 people. With all the Bay Area faults, Allen said his research shows there's a "two-in-three chance" the Big One could be soon. "We're overdue for a recurrence," Allen said. The last major earthquake in the Bay Area occurred more than a decade ago, when an earthquake rattled Napa Valley in 2014. The 6.0 magnitude quake in Wine Country killed one person and injured 300 people. The incident caused more than $1 billion in damage across Napa and neighboring cities, including Vallejo, California, which took years to rebuild. Then there was theLoma Prieta earthquakethat rocked the San Francisco Bay Area in 1989, killing 63 people and injuring nearly 3,800 others. The earthquake disrupted the World Series and damaged the Bay Bridge, Oakland's Cypress Freeway, and swaths of San Francisco. It caused up to $10 billion in damage. "There's this perception that large quakes are frequent, but actually, they are quite rare," Goulet said. "We just don't know when they will happen." The Los Angeles area also stands a chance of getting a major earthquake, as there's a 60% chance of a 6.7 magnitude quake within the next 30 years, the USGS said. Additionally, there is also a 46% probability that a 7.0 magnitude earthquake will hit L.A. and a 31% chance a 7.5 magnitude quake will strike during that same period. Allen, the Berkeley seismologist, said Southern California has just as high an earthquake risk compared to its Northern California counterparts. "They face a similar threat, if not higher," Allen said. Goulet added that with Los Angeles and the surrounding areas being so populous (nearly 18.6 million residents according to California Finance Department statistics), there is a high probability for major destruction. She cites the disastrous 6.7 earthquake in Northridge, California, in 1994, which killed 60 people and injured more than 7,000. The devastation also left thousands of buildings and structures collapsed or damaged across Los Angeles, Ventura, Orange and San Bernardino counties. Thousands of residents became homeless as the aftermath caused between $13 billion to $20 billion in damages. "The closer an earthquake is to a large population, the greater the impact will be," Goulet said. Goulet also points to a sequence of earthquakes in 2019 in Ridgecrest, California. A 7.1 magnitude earthquake rattled the city two days after an initial 6.4 magnitude quake. Goulet was among a USGS on-site team researching the first quake when, surprisingly, the second temblor struck. "It was terrifying," Goulet said. "We were there taking measurements and just as we were finishing our work and planning for the next day, the second one occurred about six miles away from us. That was extremely close." Goulet said she remembers reassuring panicked residents that everything would be okay. "That's why we cannot specifically predict earthquakes, when and where they will occur and how big they will be," Goulet added. "But what we can do is collect all of the research that causes earthquakes and the probabilities, which are called probabilistic seismic hazard analysis." Now what?:Federal database that tracked costly weather disasters no longer being updated Huge earthquakes have long been an existential crisis for millions along the West Coast, as described in a2022 USA TODAYarticle. But experts said there are real things people can do to help them prepare for a major disaster. If you experience an earthquake, Sarah Minson, a research geophysicist with the USGS's Earthquake Science Center in Mountain View, California, advises not to run. "If you feel shaking, you should drop, cover and hold on to protect yourself," Minson said. "Don't go anywhere. Don't run outside. A huge number of the injuries that occur in earthquakes are people stepping on broken glass or trying to run during the shaking and falling down." Allen, the Berkeley seismologist, recommends that households create an earthquake plan, including where they will meet and possibly have a bag or suitcase ready for at least a couple of days. Residents will at least want a flashlight and a way to charge their phone. They should also be prepared to have access to electricity or water cut off for days or weeks. Here are a few practical tips: When trying to use your phone,text–don't call. In a disaster, text messages are more reliable and strain cell networks less. To power your phone, you can cheaply buy a combination weather radio, flashlight and hand-crank charger to keep your cell running even without power for days. A cash reserve is good to have,USGS seismologist Lucy Jonespreviously said. You'll want to be able to buy things, even if your credit card doesn't work for a time. Simple things like securing bookshelves can save lives.Downloading an early warning appcan give you precious moments to protect yourself in the event of a big quake. Buying earthquake insurance can protect homeowners. And taking part ina yearly drillcan help remind you about other easy steps you can take to prepare. Contributing:Elizabeth WieseandJoel Shannon This article originally appeared on USA TODAY:Is California 'overdue' for a major earthquake?
