The U.S. Geological Survey said the shallow quake was a magnitude 4.4 and occurred at 2:39am PST. It wouldn't be a big surprise if we had a big quake on the Hayward Fault. While many were jolted out of their beds, there was no preliminary reports of damage.
On average, the fault produces a large natural disaster every 160 years, with a margin of error of about 80 years.
No damage or injuries were immediately recorded.
People in Santa Cruz called in to the KSBW newsroom reporting that they felt the shaking for up to 10 seconds.
An natural disaster woke many Berkeleyans shortly after 2:39 a.m. Thursday.
"We know that it's ready [and] is capable of having another big natural disaster at anytime", Tom Brocher, seismologist at the USGS, told Newsweek. In fact the 150th anniversary is coming up - we think that natural disaster was a magnitude 6.8 or so. A magnitude 6.8 quake occurred on October 21, 1868, and was known at the time as the "Great San Francisco natural disaster". "It may mean less likelihood of a larger quake to follow".
The last major quake along the Hayward fault happened in October of 1868, when a magnitude 6.8 hit the San Francisco Bay region, making it the most destructive natural disaster in the state's history.
The 1868 quake was the 12th most lethal in California history, killing 30 people.
The California Governor's Office of Emergency Services said there were no reports of damages from the region at this time.
One Twitter user posted a video showing an aisle in a Safeway grocery store in San Leandro, peppered with toiletries that had fallen to the ground.
The quake is said to be associated with the Hayward fault, which aligns underneath the eastern side of the Bay area - from Hayward through Berkeley.