[Axenolith]

That relatively earthquake free area west of Washington and Oregon is the remant Juan De Fuca plate continuing to subduct under the N. American plate. Fractional melting of the subducting plate, and its predecessor the Farallon Plate, is the source of the Cascade volcanoes. That partial melting is still going on under Oregon and California.

[calawah98]

And the plates are moving north. I believe I read one time how much they had, since they have been monitoring them, but do not recall at the moment

[Quix]

Thanks for the plate specifics.

It seems to me you'd be the best one to host a geology ping list. You up to it?

On the #216 post map of seismic stations . . . why would they string several strings of them out as they have across Northern Nevada toward Yellowstone? Are there some specific faults in those areas that they've strung them perpendicular across or alongside of?