The quake hit right near the Oakland Zoo. It was initially registered at 4.1 but has since been downgraded several times, and the USGS now says it was a magnitude 3.8 quake.
Two aftershocks, magnitudes 3.0 and 2.8, hit at 9:07 a.m. in the same area.
Shaking from the earthquake was reported across much of the East Bay and BART trains stopped as a precaution.
Oakland police and fire tell ABC7 Eyewitness News there have been no reports of damage.
The quake measured at a depth of 5.2 kilometers.
The closer to the surface an earthquake starts, the more ground shaking and potential damage it will cause.
People typically report feeling earthquakes larger than about magnitude 2.5, according to the USGS.
Bay City News contributed to this story.
MAP: Significant San Francisco Bay Area fault lines and strong earthquakes
Zoom in on the map below and compare where you live to the significant faults and where strong earthquakes have struck in the Bay Area.
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