An earthquake of preliminary magnitude 4.9 shook residents awake across the Bay Area at 1:41 a.m. early Thursday morning, according to the United States Geological Survey.
The earthquake was centered near Boulder Creek in the Santa Cruz Mountains. Shaking was felt in Oakland, and San Francisco and as far as Petaluma. At a home near the epicenter, a book was knocked off the shelf.
Reports of damage were not immediately available. People across the Bay Area got earthquake alerts, which go out for magnitude 4.5 quakes and above.
The quake was originally reported at 5.1 magnitude but quickly revised down to 4.9.
Various faults run through the Santa Cruz Mountains area. The 6.9 magnitude Loma Prieta earthquake struck in 1989 off the San Andreas Fault was epicentered near Mount Loma Prieta in the Santa Cruz Mountains.