A magnitude 5.6 earthquake struck northern California early Wednesday, triggering alerts across the Bay Area. The quake was recorded about 6 miles from Redwood Valley at 8:10 a.m. PT, followed by a smaller 2.5 aftershock, and officials said a tsunami was not a
The ground shook across northern California on Wednesday morning, and by the time the alert messages started landing on phones across the Bay Area, residents in Mendocino County already had a clearer picture of what had happened.
A magnitude 5.6 earthquake rattled the region at 8:10 a.m. PT, according to the United States Geological Survey. The quake was recorded just over 6 miles from Redwood Valley, with data from the USGS showing it occurred at a depth of 8.1 miles. People across the region reported feeling the shaking.
For now, the most urgent questions remained unanswered: it was not immediately clear whether anyone was injured or whether damage had been reported.
Redwood Valley sits in Mendocino County, about 125 miles north of San Francisco. Shortly after the initial quake, another jolt followed—officials said a smaller 2.5 magnitude earthquake struck again in Redwood Valley.
As of 9 a.m. PT, officials said a tsunami was not anticipated.
Gov. Gavin Newsom’s office moved quickly to get in sync with local responders. In a post on social media, his office said, “The Governor’s Office is closely coordinating with emergency officials and assessing potential impacts and damage.”
The sequence of events—one damaging-sized quake followed by an aftershock, while state and local officials check for impacts—puts familiar pressure on communities that are used to monitoring risk but never fully ready for the moment the ground starts to move.
There’s also a reminder embedded in how earthquake size translates into real-world effects. A guide from Michigan Technological University breaks down impacts by magnitude: below 2.5 is generally not felt; 2.5 to 5.4 brings minor or no damage; 5.5 to 6.0 can mean slight damage to buildings; 6.1 to 6.9 can cause serious damage; 7.0 to 7.9 is major with serious damage; and 8.0 or greater can produce massive damage that can destroy communities.
For Wednesday’s quake, the magnitude sits in the 5.6 range—close to the threshold where slight building damage becomes possible—while officials continued to assess what, if anything, the shaking left behind.
Northern California earthquake USGS 5.6 Redwood Valley Mendocino County aftershock 2.5 tsunami not anticipated Gov. Gavin Newsom