LOS ANGELES: A magnitude seven earthquake hit off the northern California coast on Thursday, prompting a tsunami warning for a large stretch of the California and Oregon coasts.

Some 4.7 million residents of California and Oregon were under the tsunami warning, the National Weather Service said. But the tsunami warning was lifted an hour later.

San Francisco and a large part of the surrounding Bay Area were under the tsunami warning.

The quake, which hit at a shallow depth of 10 kilometres, was centred 63km west of the town of Ferndale, a sparsely populated portion of the northern California coast, the US Geological Survey said.

Authorities in Berkeley, California, issued an evacuation order for parts of the city on the San Francisco Bay, according to an alert sent to residents.

Smartphone users received warnings urging them to move to higher ground immediately.

“A series of powerful waves and strong currents may impact coasts near you,” the warning said. “You are in danger. Get away from coastal waters.”

The National Weather Service, which issued the warning, withdrew it around midday, shortly before the first waves had been expected.

The quake appeared to have been felt across the region, including in the San Francisco Bay Area, where some people said they had felt rolling waves underfoot.

Marc Buller, an attorney who lives in Eureka, a port city in northern California close to the offshore epicenter, said he had experienced a lot of quakes, but this one felt unusual.

“It was an intense jolt. When the big jolt stopped, it felt like the house was on rollers,” he said.

“It was like when you throw a big stone in water and the ripples go out, it was like the earth was doing that.”

About 19,000 clients were without power in Humboldt county — up from near zero before the earthquake struck, according to data from PowerOutage.us.

The office of California Governor Gavin Newsom wrote on social media that the governor “is now meeting state emergency officials and working to ensure Californians are safe”.

The US west coast is the confluence of several of the Earth’s tectonic plates, and tremors are common.

The area has been struck by a number of major earthquakes, including a 1994 quake that hit Northridge, in the Los Angeles area, killing dozens of people and injuring thousands more.

The San Francisco earthquake of 1906, which also caused a tsunami, is thought to have killed upwards of 3,000 people, some of whom died in fires that erupted after the powerful tremor.

Published in Dawn, December 6th, 2024