Scientists not overly concerned over PNW weekend earthquake swarm. Here’s why
A series of earthquakes off the Washington state coast last weekend aren’t a threat to the region, and no tsunami warning was issued, seismologists said Sunday.
More than 18 quakes were recorded in an “active swarm” of tremors starting around midnight Sunday on the Juan de Fuca Ridge about 250 miles due west of Aberdeen, according to the Pacific Northwest Seismic Network.
Most of the quakes were in the magnitude 3 and 4 range and all were about 6 miles deep, according to PNSN data from the University of Washington.
“The USGS locations show that these are not anywhere near the Cascadia Subduction Zone. They are also not at the Axial Seamount Volcano, which has been predicted by others to be nearing an undersea eruption, though they are farther north along the same ridge,” officials at PNSN tweeted Sunday.
The Cascadia Subduction Zone is a part of the Earth’s crust that is slowly moving east and grinding under the West Coast from northern Vancouver Island to Northern California. It is believed to be capable of producing a catastrophic earthquake.
The Axial Seamount Volcano is on the Juan de Fuca Ridge about 300 miles west of Astoria, Ore., and last erupted in 2015.
Another eruption is likely later this year, according to Oregon State University researchers who were quoted in the Statesman Journal of Salem, Ore.
Earthquakes of magnitude 2.5 to 5.4 are often felt and can cause minor damage, according to Michigan Technological University.
There were no reports that any quakes in Sunday’s swarm were felt, according to the U.S. Geological Survey.
This story was originally published April 13, 2026 at 1:17 PM with the headline "Scientists not overly concerned over PNW weekend earthquake swarm. Here’s why."
