A powerful 7.0 magnitude earthquake struck off the Northern California coast Thursday morning, prompting temporary tsunami warnings for coastal areas from Davenport California to southern Oregon.
The earthquake occurred at 10:44 a.m. approximately 62 miles west of Ferndale, California, according to the United States Geological Survey (USGS). The tsunami warning was later canceled at 11:55 a.m. by the Tsunami Warning Center.
The tremor was felt as far south as San Francisco, where residents experienced several seconds of rolling motion. The quake triggered immediate precautionary measures, including the evacuation of the San Francisco Zoo and suspension of BART train service through the Transbay Tube.
Harold Tobin, director of the Pacific Northwest Seismic Network, identified the event as a strike-slip earthquake occurring in the Mendocino fault zone - an area where three tectonic plates intersect: the Pacific, North American, and Juan de Fuca plates.
"This is the exact point where the Cascadia Subduction Zone ends to the south and the San Andreas Fault begins," Tobin explained. "It's the most seismically active place in California over the past decades."
The earthquake was the strongest recorded in the region since the 1990s. While over 5.3 million Californians were initially under the tsunami warning, and an estimated 1.3 million people were close enough to feel the quake, no immediate damage was reported.
Local residents received emergency alerts warning of potential powerful waves and strong currents, instructing them to move to higher ground or inland areas. The warning advised people to stay away from coastal areas until local officials declared them safe.
Several aftershocks followed the main quake, though experts noted that this event occurred outside the Cascadia Subduction Zone and is unlikely to increase the risk of additional earthquakes in that area.