A strong earthquake was felt widely across northern California on Thursday, as authorities issued a tsunami warning.
The quake struck at 10.44am local time west of Ferndale, a small city in coastal Humboldt County near the Oregon border, according to the US Geological Survey.
It was felt as far south as San Francisco, where residents felt a rolling motion for several seconds, and was followed by smaller aftershocks.
The San Francisco Bay Area Rapid Transit District, known as Bart, has stopped traffic in all directions through the underwater tunnel between San Francisco and Oakland.
At least 5.3 million people in California were under a tsunami warning after the magnitude 7.0 earthquake, the US Geological Survey said, in a yellow alert, which predicts localised but minimal damage.
More than 1.3 million people lived close enough to the quake that they could have felt it, the USGS estimated.
The National Weather Service urged residents along the Northern California coastline, including in the San Francisco Bay Area, to move inland because of the threat of a tsunami.
A wave could reach the San Francisco coastline as early as 12.10pm local time, said Rachel Kennedy, a meteorologist with the National Weather Service.
She said forecasters were waiting for a report on how high potential waves could be. She called it “a pretty dangerous situation”.
The San Francisco Zoo’s visitors have been evacuated as a result of the earthquake, the zoo said in a post on X, formerly Twitter. The animals have been secured and staff have been moved to higher ground.
Throughout northern California phones buzzed with a tsunami warning from the National Weather Service that said: “A series of powerful waves and strong currents may impact coasts near you. You are in danger. Get away from coastal waters. Move to high ground or inland now. Keep away from the coast until local officials say it is safe to return.”
