[Alas Babylon!]

At that latitude, the northern end of the Juan de Fuca plate is subducting eastward under the North American plate, while the Pacific plate to the west and the Juan de Fuca plate is spreading out, like the Mid-Atlantic ridge.

So, could be normal. Earthquakes along this plate generally reduce pressure. However, a big one could let go several miles in and deep, and then...

Fo’getaboutit!

Tsunami's, Mt Rainer blowing its top, Shasta, Mt Baker, Mt Hood, what a mess!

[hoagy62]

If the Cascadia let’s go, I doubt any of the Cascade volcanoes would erupt.
Granted, Seattle, Portland, and a bunch of other places would be wrecked, but I doubt there would be any eruptions.