US Lifts Tsunami Warning In Northern California After Earthquake

The National Weather Service lifted tsunami warnings for Northern California and parts of southern Oregon after a 7.0-magnitude earthquake struck off the coast of Ferndale, California, on Thursday morning.

CBC reports that the earthquake, which occurred at 10.44 am local time, was centred approximately 62 miles west of Ferndale at a depth of less than a mile, according to the United States Geological Survey (USGS).

The Tsunami Warning Center initially issued a warning for the coast from Davenport, California, to the Douglas-Lane county border in Oregon but cancelled it at 11.55 am.

Humboldt County, the area closest to the epicentre, reported no casualties.

However, broken water mains, shattered windows, and homes displaced from their foundations were noted, according to Humboldt County District 2 Supervisor Michelle Bushnell.

According to Skynews, State Sen. Mike McGuire confirmed that about 10,000 residents were without power.

The temblor was part of a seismic swarm, with at least 17 earthquakes recorded across Northern California on Thursday, primarily near Humboldt County.

Four quakes were centred around Ferndale, while the town of Petrolia experienced at least 10 events ranging between magnitudes 3.1 and 4.2.

USGS Director of the Earthquake Science Center, Christine Goulet, explained that the earthquake’s shallow depth made it particularly intense. 

“Following a 7, there could be fairly large aftershocks,” she said, adding that there is a 5 per cent chance of another earthquake above magnitude 6.0 occurring in the region within the next week.

Harold Tobin, director of the Pacific Northwest Seismic Network, identified the quake as a strike-slip event in the Mendocino fault zone, where the Pacific, North American, and Juan de Fuca tectonic plates intersect.

“This is the exact point where the Cascadia Subduction Zone ends and the San Andreas Fault begins,” Tobin said, noting it’s one of California’s most seismically active regions.

Despite concerns, Tobin clarified that the earthquake did not occur in the Cascadia Subduction Zone, a fault known for its potential to generate magnitude-9.0 earthquakes and massive tsunamis.

“It’s not likely to increase the risk of an earthquake there,” he added.

The earthquake also triggered the USGS ShakeAlert Earthquake Early Warning System, providing residents from Eureka to Fort Bragg a few seconds of notice before the shaking began.

“It looks like the people close got several seconds of advance notice,” Goulet said.

This earthquake marks one of eight magnitude-7.0 or higher events recorded in the region over the past century, underscoring the area’s seismic volatility.