SAN FRANCISCO (KGO) — A magnitude 7.0 earthquake struck Northern California on Thursday, triggering a tsunami warning and multiple aftershocks.

The tsunami warning – which affected at least 5.3 million people before it was lifted around 12 p.m. Pacific time – was in effect for coastal areas in California and Oregon, including several parts of the Bay Area.

The epicenter of the earthquake is offshore near Petrolia in Humboldt County, according to the U.S. Geological Survey. The USGS estimated that more than 1.3 million people lived close enough to the quake to have felt it to some extent.

The map below shows the epicenter of the earthquake and the magnitude of the shaking. There were reports of tremors in the state from northern Del Norte County and southern San Mateo County.

Since the earthquake struck at 10:44 a.m. Pacific time, USGS data through 6 p.m. shows that there have been about 60 aftershocks so far in Northern California.

The strongest aftershock was magnitude 5.0 and the lowest was magnitude 2.4. The aftershocks occurred near the epicenter of the original earthquake. Two smaller earthquakes were recorded elsewhere in Northern California, including in Lake County.

There will likely be several more aftershocks in the next few days.

According to the USGS, there is a 5% chance of a magnitude 6 or larger earthquake and a 34% chance of a magnitude 5 earthquake occurring in the next week.

ABC News and the Associated Press contributed to this report.