Map showing epicenter of Aug. 24 earthquake. Source: USGS
Map showing epicenter of Aug. 24 earthquake. Source: USGS

A magnitude 6 earthquake shook many people awake in Berkeley at 03:20:44 a.m. on Sunday Aug. 24.

According to the U.S. Geological Survey (USGS), the epicenter of the shaker was 4 miles north-west of  American Canyon, California, and registered a depth of 6.7 miles. American Canyon is north of Vallejo and about 28 miles north of Berkeley.

People took to Twitter almost immediately after the quake, which was felt around the Bay Area and lasted a significant time. It was described by one person as “a long roll.”

Early reports suggest Napa, which is 6 miles south-south-west of its epicenter, may have felt the quake most strongly. People there are posting photographs of overturned furniture and broken household items on Twitter. On Sunday morning, PG&E was reporting power outages affecting more than 5,000 customers in areas of Napa and Sonoma.

Laura Morland, who lives in North Berkeley, just north-east of Live Oak Park, described the quake as “long, slow, and steady. “I counted eight or nine seconds for the main shaking, and a couple more seconds for ‘residual trembling,’” she wrote Berkeleyside by email. “It wasn’t sharp, but it was notable for its length.”

Writing in the comments to this story, reader “DisGuested” said it felt like the quake lasted about 15 seconds with a “steady rocking, but no jolt.”

If the early USGS calculations are correct, this was the largest earthquakes in the Bay Area since Loma Prieta in 1989.

USGS shake map for the Aug. 24 American Canyon earthquake shows where it was felt most intensely.
This USGS Shake Map for the Aug. 24 American Canyon earthquake shows its instrumental intensity.

At 3:38 a.m. the  California Highway Patrol reported via Twitter that it was checking over crossings and bridges for obvious signs of structural integrity. It encouraged the public to report any signs in their area. Follow CHP on Twitter at @CHP_GoldenGate for updates on road conditions in the Wine Country in the aftermath of the quake.

The City of Berkeley organizes regular emergency preparedness training workshops. The next Community Emergency Response Team (CERT) class is on Aug. 30. Visit the city’s Office of Emergency Services website page for details.

Read about emergency preparedness on Berkeleyside.

The USGS encourages people to share their experience of earthquakes. Tell them what it felt like on their website.

Let Berkeleyside know in the comments, via Twitter or Facebook how you experienced the quake.

This story was updated with new information as it became available.

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Tracey Taylor is co-founder of Berkeleyside and co-founder and editorial director of Cityside, the nonprofit parent to Berkeleyside and The Oaklandside. Before launching Berkeleyside, Tracey wrote for...