There is no doubt in my mind that a "big one" will hit the west coast of the U.S. or Canada within the next century.

My 13th birthday saw the big Alaska quake ... it hit 9.2 on the Richter scale in Anchorage. That was about three times more powerful than the quake that just hit Japan, and there was a quake in 1960, down in Chile, that was three times more powerful than the Alaska quake, and possibly the largest one ever recorded (was 9.5 on the Richter scale).