An active swarm of earthquakes was detected about 250 miles offshore of Washington state.

All 18 Sunday morning earthquakes remained in the 2-4 magnitude range, which is quite common over the course of a year.

Harold Tobin with the Pacific Northwest Seismic Network said the swarm of earthquakes off of Washington's coast is not a concern.

The earthquake-generating geology between Alaska and Washington is very similar. That’s because large portions of both states sit on top of a giant fault, where crustal plates are being shoved past each other. A powerful 7.0 earthquake struck near ...

“Quite an active swarm” of smaller earthquakes was recorded Sunday morning as well off Washington’s coastline, according to the Pacific Northwest Seismic Network. The second-largest quake came around 8:04 a.m. at a magnitude of 4.1.

A swarm of 18 earthquakes were recorded 250 miles offshore from Washington, the strongest recorded with a 4.2 magnitude.