Map showing potential tsunami warning off the coast of Northern California after a reported 7.0M earthquake on Dec. 5th, 2024.
USGS
An earthquake ruptured off California’s coast on Thursday morning, triggering a tsunami warning for the coast of Northern California and southern Oregon.
The earthquake, a magnitude-7.0 temblor, rumbled at around 10:44 a.m., about 62 miles west of Ferndale, California, according to the United States Geological Survey.
A tsunami warning was issued for the coast between from Davenport, California, to the border between Douglas and Lane counties in Oregon. The Tsunami Warning Center canceled the warning at about 11:55 a.m.
Earthquakes can trigger tsunamis when they displace the seafloor, causing waves that can rush toward shore. A tsunami warning indicates that significant inundation and coastal flooding is expected, based on preliminary information about the quake’s position.
Harold Tobin, the director of the Pacific Northwest Seismic Network, said the 7.0-magnitude temblor was a strike-slip earthquake about 50 miles offshore.
Strike-slip earthquakes take place when two plates slide past one another.
“It is not impossible for a strike-slip earthquake to produce a tsunami,” Tobin said.
A M 7.0 earthquake reported- 63 km WNW of Petrolia, CA on Dec. 5th, 2024.
Source: USGS
The quake ruptured in the Mendocino fault zone, at the intersection of three tectonic plates – 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 said. “It’s the most seismically active place in California, overall, over the past decades. It’s not a surprise to get an earthquake of this magnitude.”
Tobin said this was the highest-magnitude earthquake produced in the area since the 1990s.
Tobin said the earthquake did not take place on the Cascadia Subduction Zone and that it was not likely to increase the risk of an earthquake there.
The Cascadia Subduction Zone is one of the biggest hazards in the U.S. The fault runs offshore along U.S. West Coast from Northern California to northern Vancouver Island. It’s capable of producing magnitude-9.0 earthquakes and tsunami waves about 100 feet tall.
