Is the “Big One” Coming? Recent Earthquakes Have Northern California on Edge

A string of powerful earthquakes overseas, combined with a recent uptick in shaking closer to home, has many Northern Californians asking an uneasy question: Is the “Big One” coming?

Earlier this month, two major earthquakes struck within days of each other abroad. A magnitude 7.0 quake hit Alaska on Dec. 6, followed by a massive 7.6 earthquake in northern Japan on Dec. 8 that triggered tsunami warnings and mass evacuations. Both regions continue to experience aftershocks, and Japanese officials have warned that another strong quake could still follow.

Meanwhile, California has seen its own flurry of seismic activity. In November and early December, clusters of small earthquakes rattled the San Francisco Bay Area and Central Coast, including a 3.8 quake in San Ramon and a 4.0 tremor near Gilroy. According to the U.S. Geological Survey, these “seismic swarms” are not unusual, but they still grab attention.

California ranks second in the nation for seismic activity, behind Alaska, and sits atop hundreds of faults. More than 70% of the state’s population lives within 30 miles of a potentially hazardous fault, including the San Andreas, Hayward, and Calaveras systems.

So what are the odds? Scientists estimate a 72% chance of a magnitude 6.7 or larger earthquake striking the Bay Area by 2043. And while small quakes don’t reliably predict big ones, they don’t rule them out either.

Bottom line: earthquakes remain unpredictable and in Northern California, they’re always a possibility.