[winoneforthegipper]

Swarms are sometimes indicative of a large strike slip as seen in the Mexico quake a few years ago...but as witnessed in Japan this year with their megaquake...it had a 7.2(i believe) on the pacific plate in strike slip motion hours before.

Of course we know that the main quake was a severe subduction zone thrust event on the North American plate.

[djf]

Well, if we look at the known subduction zones around the world we might be able to get a clue about what to expect in Cascadia before/after a large event.

Japan - hundreds, if not thousands of micro quakes offshore there every day.
Indonesia - Same deal. Probably hardly a day goes by without a 4 or 5 in Indonesia somewhere
Chile - not so many microquakes, but you do see LOTS of 4’, 5’s, 6’s, and 7’s along a stretch of about 500 miles around Concepcion - site of the 1960 9.5+ subduction event, the largest quake ever recorded in history...
Kamchatka - What U see is what U get - this is a hodgepodge of large and micro quakes of all sorts. Not a day goes by that we don’t see a large quake in that region.

Compared to these regions, Cascadia is in a coma!!!

And I overlooked putting Alaska and the Aleutians on the list!