A light, 4.7-magnitude earthquake struck in Northern California on Wednesday, according to the United States Geological Survey.

The temblor happened at 6:34 p.m. Pacific time about 2 miles northwest of Cobb, Calif., or about 70 miles north of San Francisco, data from the agency shows.

As seismologists review available data, they may revise the earthquake's reported magnitude. Additional information collected about the earthquake may also prompt U.S.G.S. scientists to update the shake-severity map.Aftershocks can occur days, weeks or even years after the first earthquake. These events can be of equal or larger magnitude to the initial earthquake, and they can continue to affect already damaged locations.