A magnitude 5.6 earthquake struck Northern California on Wednesday morning, rattling homes, knocking goods off store shelves, and cutting electricity to thousands of residents in Mendocino County.
The quake hit at 8:10 a.m. Pacific time, centered about seven miles north of Redwood Valley, according to the U.S. Geological Survey.
The agency initially measured the shake at magnitude 6.0 before revising it down to 5.6. USGS data placed the rupture roughly five miles below the surface.
Mendocino County officials confirmed several people were hurt, though no deaths were reported, and said no major structural damage had been identified so far.
PG&E reported that around 10,000 customers lost electricity in the county, with about half restored by mid-afternoon. The utility said its gas lines and power-generating equipment escaped damage.
Footage shared with local news outlets showed merchandise toppling from shelves in Willits, Redwood Valley, and Upper Lake, along with a Willits home where cabinet contents spilled onto the floor. Other clips captured vehicles rocking back and forth as the ground shook.
Shaking Felt From Eureka to Sacramento, Aftershocks Continue
The tremor’s reach extended far beyond the epicenter. Residents from Eureka in the north down to Sacramento in the southeast told the USGS they noticed shaking, with those nearest the quake’s center describing far more intense movement.
Seismologist Lucy Jones noted this was the strongest earthquake to hit the region in almost 90 years, despite the area sitting away from any major fault line.
She said the area does experience earthquakes, but they tend to be milder than this one, adding that aftershocks remain likely but should stay relatively minor.
The region’s early-warning system appeared to perform well. ShakeAlert notifications reached phones across Northern California and into parts of Oregon, feeding into the MyShake app.
Berkeley seismology officials estimated roughly 650,000 people received alerts, and preliminary data suggested 99 percent of recipients got the warning before any shaking reached them, assuming they felt it at all. Residents in San Francisco reportedly had about 35 seconds of advance notice.
Smaller aftershocks followed the main quake, a pattern experts say is typical as a fault adjusts after slipping. Such follow-on tremors can strike anywhere from days to years later and sometimes match or exceed the original quake’s strength, raising risks for structures already weakened.
Mendocino County’s Sheriff’s Office continued assessing potential damage, while Cal Fire’s Howard Forest Emergency Command Center reported no incoming damage reports as of Wednesday.
Officials urged drivers to avoid major roads so crews from Caltrans, PG&E, and the county could inspect infrastructure and make repairs.
Willits city officials said they hadn’t received reports of injuries or damage to municipal infrastructure, though crews worked through the day addressing downed power lines, possible gas leaks, and water main breaks.
Governor Gavin Newsom’s office said it was monitoring the situation and coordinating with emergency responders to evaluate the quake’s impact.
Local residents shared a range of experiences with the shaking — from swaying clock weights and rattled light fixtures to a swimming pool sloshing water onto a backyard in Vacaville.
A cafe in Ukiah and a nearby Buddhist monastery near the epicenter both reported feeling the quake firsthand, with the monastery noting that numerous items fell over, though no one was injured.
