An earthquake shook the Bay Area on Thursday morning.

LATEST April 2, 8:52 a.m. The U.S. Geological Survey downgraded a major temblor that shook the Bay Area to a magnitude 4.6. The preliminary estimate for the quake was 4.9. The quake was centered 1 kilometer east-southeast of Boulder Creek in the Santa Cruz Mountains at a depth of 6.7 miles. Over 27,000 people in the region reported feeling the temblor, including in areas far from the epicenter like Sacramento and Santa Rosa, according to the USGS. 

No aftershocks were reported in the hours after the quake struck. The USGS estimates the chance of a magnitude 3.0 aftershock over the next week is currently 27%. They estimate a 4% chance of a magnitude 4.0 aftershock arriving.

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April 2, 1:53 a.m. A preliminary magnitude 4.9 earthquake rattled the Bay Area shortly before 1:45 a.m. Thursday, shaking awake sleeping residents and surprising people with alerts to their phone. According to the U.S. Geological Survey, the earthquake was centered near Boulder Creek, an unincorporated area in the Santa Cruz Mountains. There were no immediate reports of injuries or damage, although the shaking was widely felt throughout the region.

A ShakeAlert was sent to phones warning of the earthquake as it hit. The service, which is used throughout the West Coast, is meant to give people a warning immediately before a large earthquake hits. The ShakeAlert warned a 5.0 earthquake was in progress; that initial magnitude was taken down slightly to a 4.9. 

According to the USGS, the chance of at least one aftershock with a magnitude of 3.0 or higher is 76% sometime this week.

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