Also, major subduction of Juan De Fuca Plate, more locally. link
We're WAY overdue.
Although the last giant earthquake hit Washington's coast 300 years ago, scientists say that the Cascadia Subduction Zone may be storing up energy to be released in the next catastrophic earthquake. The stresses detected off Washington's coast could generate a huge earthquake (magnitude 9 or more). That would rival the largest earthquake ever recorded. (A magnitude 8.7 earthquake would release 1,000 times the energy of the magnitude 6.6 earthquake that struck Los Angeles in 1994.)