A 3.3-magnitude earthquake shook the San Francisco Bay Area hours after an earlier tremor and days after a deadly Northern California temblor, the U.S. Geological Survey reports. The 3-mile deep quake hit near Union City at 6:22 p.m. Wednesday, Dec. 21, according to the USGS. About 1,600 people from as far away as Chico and Los Banos reported feeling the tremor to the agency. “A little shaking in the East Bay just a few moments ago,” wrote one resident on Twitter. “Felt it here in Union City big jolt,” read another post. “That was quite a quick quake in Union City,” a third Twitter post read. The earthquake follows a 2.9-magnitude tremor north of San Leandro east of Oakland at 8:30 a.m. Wednesday morning felt by more than 1,000 people. A 6.4 magnitude tremor struck about 8 miles west of the small city of Ferndale, population 1,400, in Humboldt County at 2:30 a.m. Tuesday, Dec. 20, The Sacramento Bee reported. Two people died and a dozen were hurt in the quake, and 14,000 people are still without power. Gov. Gavin Newsom has proclaimed a state of emergency for the county. Dozens of aftershocks continue to rattle the Ferndale area, which is about 260 miles north of the San Francisco Bay Area. Union City is a community of 69,000 about 25 miles southeast of San Francisco. Magnitude measures the energy released at the source of the earthquake, the U.S. Geological Survey says. It replaces the old Richter scale.