I feel the earth move

Did a wee bit of digging and turns out that we have been having a lot of very small quakes. Not large enough to trigger the alert system I subscribe to but large enough to get noticed. From Oregon Public Radio:

Thousands Of Tremors Hit Northwest, But Don't Necessarily Signal The Big One
Did you feel the ground move this week? Not likely, even though a wave of small tremors was spreading under people’s feet in the coastal Pacific Northwest.

The Pacific Northwest Seismic Network has detected more than 4,500 tremors over the past two weeks deep beneath the Olympic Peninsula and southern Vancouver Island and from another swarm stretching from Eugene to the Siskiyou Mountains.

It’s a phenomenon called “episodic tremor and slip” or “slow slip.” Humans can’t feel it, but seismologists have discovered this happens along Cascadia’s tectonic plate boundary on a regular basis — every 14 months or so in the case of Puget Sound and on a different cycle in Oregon and northern California.

The key question for seismic network director Harold Tobin at the University of Washington (UW) is whether the current slow slip has implications for the feared Big One, a large Cascadia earthquake.

And what keeps me awake at night:

The last full rip of the Cascadia Subduction Zone happened in January 1700. The exact date and destructive power was determined from buried forests along the Pacific Northwest coast and an “orphan tsunami” that washed ashore in Japan. Geologists digging in coastal marshes and offshore canyon bottoms have also found evidence of earlier great earthquakes and tsunamis. The inferred timeline of those events gives a recurrence interval between Cascadia megaquakes of roughly every 300 to 600 years, according to the Pacific Northwest Seismic Network.

Fortunatley, Camano Island is well sheltered by the other San Juan islands, Whidbey in particular. FEMA shows us as getting a gradual five foot surge but that will be it.

Classical reference in the post title