A powerful 7.0 magnitude earthquake shook northern California this Thursday, causing a tsunami warning that extends to Oregon, reports the United States Geological Survey (USGS).
The earthquake occurred at 10:44 a.m. (18:44 GMT) at a depth of 10 kilometers northwest of Petrolia, a city in Humboldt County.
This shock was followed three minutes later by an aftershock of magnitude 5.8 9 kilometers from Cobb, in northern California, and three others of 3.3; 3.7 and 4.2 respectively, according to USGS data.
Initially, USGS classified the intensity of the earthquake at 6.6, but later raised it to 7.0.
Authorities have issued a tsunami warning for coastal areas of northern California and central Oregon.
Residents of the San Francisco Bay area have received tsunami warnings and have been asked to be alert for possible evacuation orders.
Authorities are currently assessing the situation and residents are advised to remain alert for possible aftershocks.
So far, no possible victims or damages have been reported.
Humboldt County is located north of San Francisco and is a forested area.
