A magnitude 3.0 earthquake hit the Marietta-Alderwood area Thursday morning around 1:40 a.m.
People reported feeling the quake in Ferndale and Bellingham.
There were no immediate reports of injuries.
This quake adds to the round of earthquakes that struck the state within the past 24 hours.
A map from the Pacific Northwest Seismic Network shows where the quakes have been over the past day.
Thursday morning, another earthquake was recorded at a magnitude of 2.6 in Bremerton. On Wednesday morning a magnitude 2.5 quake hit near Enumclaw.
The quakes were not deep underground, only ranging from one to about five miles deep. They are also in the vicinity of known fault zones capable of causing serious damage in the Puget Sound region as the Seattle Fault line is believed to be capable of a magnitude 7.2 earthquake.
While the quakes are concerning, are they tied to the major fault lines?
"We think the Seattle Fault is complicated," said John Vidale of the Pacific Northwest Seismic Network. Vidale also serves as the official seismologist for the state of Washington. "It could be in that system of faults, but we don't know if there's a primary fault down there, and if there is if these earthquakes are on it."
What makes the Seattle Fault so dangerous is that it's very shallow, rising to the surface.
"It's very interesting of course," says PNSN seismologist Renata Hartog. "Because how the Seattle Fault is driven from below is interesting to know. We don't know that very well at the moment."
But scientists want to learn more, and each quake becomes another data point for study, bringing the inaccessible depths under Puget Sound into sharper focus.