Small Earthquake Jolts Berkeley Ahead of Statewide Preparedness Drill

The quake occurred about one hour before the Great California ShakeOut, a statewide earthquake preparedness exercise that took place at 10:16 a.m.

Rudy Blalock

Published: 10/16/2025, 5:03:23 PM EDT

Small Earthquake Jolts Berkeley Ahead of Statewide Preparedness Drill — Drinks and other food items are toppled on the floor inside Hoby's Market and Deli after a 7.0 magnitude earthquake, in Scotia, Calif., on Dec. 5, 2024. (Dylan McNeill/The Times-Standard via AP)

A minor earthquake rattled the East Bay on Thursday morning, striking less than an hour before millions of Californians participated in the state's annual earthquake preparedness drill.

According to the U.S. Geological Survey, an earthquake with a preliminary magnitude of 3.1 hit the Hayward Fault near Berkeley at 9:23 a.m. Residents throughout the East Bay and portions of San Francisco reported light shaking to the USGS website. No immediate damage or injuries were reported.

The quake occurred about one hour before the Great California ShakeOut, a statewide earthquake preparedness exercise that took place at 10:16 a.m. According to data from the event’s website, at least 10 million people across California, including 1.6 million in the Bay Area, participated in the drill at schools, workplaces, homes, and other locations.

The same section of the Hayward Fault experienced a magnitude 4.3 earthquake on Sept. 22, along with several aftershocks.

The annual ShakeOut drill is held each Oct. 16 to commemorate the 1989 Loma Prieta earthquake. That magnitude 6.9 earthquake claimed 63 lives, injured and displaced thousands, and caused extensive damage to buildings and infrastructure.

"When it comes to earthquakes, practice makes perfect and seconds can save lives. California is leading the nation to its advanced technology can detect shaking before it starts and notify Californians when to take protective action for an earthquake," Gov. Gavin Newsom said in a Thursday press release ahead of the event.

California's Earthquake Early Warning System, launched under Newsom's administration, uses ground motion sensors throughout the state to alert residents before shaking begins. The MyShake app, which has been downloaded more than 4 million times, can provide Californians with up to 30 seconds of advance warning for earthquakes of magnitude 4.5 or higher.

The free app is available in six languages—English, Spanish, Traditional Chinese, Tagalog, Korean, and Vietnamese—and can be downloaded on iOS, Android, and Chromebooks. The app includes earthquake and tsunami preparedness resources and features a Homebase function that enables users to receive alerts at a designated location even when location services are disabled.

According to Newsom’s office, California has more than a 99 percent probability of experiencing a magnitude 6.7 or greater earthquake within the next 30 years.

Earlier this week, the Governor's Office of Emergency Services conducted a statewide tour featuring an earthquake simulator to educate residents about preparedness and the MyShake app. The tour stopped at UC Davis, Cal State Fullerton, and the San Francisco Zoo before ending Thursday at San Diego Waterfront Park.

The warning system detects the faster-moving P-wave from a rupturing fault, which arrives before the slower, more destructive S-waves and surface waves. Sensors across California detect these initial waves and transmit data to an alert center, where the earthquake's location and magnitude are calculated and sent out through alerts.