Earthquake warnings flash across two US states as multiple quakes rock West Coast
Multiple strong earthquakes off the West Coast have sent shockwaves across two states on Wednesday morning.
Three were detected less than 100 miles from the coast of California and Oregon, all setting off emergency alert signals in the area.
The first alerts were sent out after the US Geological Survey (USGS) detected a magnitude 5.7 earthquake in the Pacific Ocean at 6.53am ET (3.53am local time).
The seaquake’s epicenter was roughly 100 miles from the West Coast, with residents in both states reporting shaking as the large tremor struck the shore.
Multiple coastal communities from Eureka, California, to Reedsport, Oregon, about 240 miles north, felt the tremors.
That seismic event was followed by a magnitude 5.1 earthquake at 8.45am ET. It struck just 55 miles from Eureka, a city of more than 25,000 people in the northern part of the state.
The third quake, this one registering at 4.5 in magnitude, erupted in the Pacific in the exact same spot as the second quake did 26 minutes later.
The California Governor’s Office of Emergency Services warned: ‘Earthquakes are unpredictable, so be prepared for aftershocks. Drop. Cover. Hold On.’
Three earthquakes were detected less than 100 miles from the coast of California and Oregon , all setting off emergency alert signals in the area, on Wednesday
The city of Eureka, California, felt the shockwaves from two of the seismic events. Eureka has a population of approximately 25,000 people
USGS confirmed that its ShakeAlert Earthquake Early Warning system was activated by the quakes, sending out automatic warnings to thousands of people’s phones and digital devices.
Officials noted that no tsunami warnings have been issued despite the proximity to the West Coast.
USGS has noted that there is a nearly 60 percent chance of another quake stronger than 3.0 striking the West Coast within the next 24 hours.
The area under and near Eureka is one of the most seismically active regions in the continental US.
The city sits near the Mendocino Triple Junction, a point where three tectonic plates, the Pacific, Juan de Fuca and North American, all meet under the Earth’s surface.
This crowded zone frequently produces earthquakes as the plates slide past each other and get stuck, causing seismic stress.
Geologists have estimated that this region has accounted for roughly 25 percent of all the seismic energy released in California over the last five decades.
Thursday’s trio of sizable earthquakes also took place near the dangerous Cascadia Subduction Zone, a nearly 700-mile-long fault line off the West Coast of North America.
A magnitude 5.1 earthquake struck the California coast, just 55 miles from the city of Eureka
The Mendocino Triple Junction is a point near Eureka where three tectonic plates meet
Scientists have long warned that the zone is overdue for a catastrophic event, with many nicknaming it the ‘Sleeping Giant.’
Simulations have shown the fault is capable of a magnitude 9.0 earthquake that would impact most of the Pacific Northwest, including major cities such as Seattle and Portland.
An April 2025 study found that a colossal earthquake along the CSZ was almost assured to take place by 2100, with a 37 percent chance it will happen at any point over the next 50 years.
If an earthquake between 8.0 and 9.0 in magnitude struck today, scientists have predicted that the shockwave could produce a 100-foot-tall mega tsunami, which would wipe out most of the nearby coastline.