What is the Cascadia Subduction Zone?

The last massive earthquake from the Cascadia Subduction Zone was in the year 1700 and measured at 9.0 magnitude. There have been countless smaller quakes, but many of these are hardly noticeable for inland residents. History, however, has something to say about that. Cascadia earthquakes usually happen every 200 to 530 years, and we are in that timeframe now. As time passes, more pressure builds in this underwater megathrust fault.

It is impossible to determine precisely when this earthquake will happen. We do know the results would be catastrophic.  The Cascadia Subduction Zone is one of the world’s most dangerous fault lines Opens a new window. This fault line spans the coast of the Pacific Northwest, putting large cities like Seattle and Portland in its path.

We only need to look to the south to see how the modern-day Pacific Northwest would be impacted. Mexico was struck by two massive earthquakes this year Opens a new window. The first quake was the most powerful earthquake to hit Mexico in a century measuring 8.1 magnitude. The second was a 7.1 earthquake Opens a new window just two weeks later. The first shock sent tremors through Mexico City despite originating in the south. This second 7.1 magnitude quake, however, unleashed catastrophic damage upon this second-most-populated city of the Americas. Hundreds perished, tens of thousands of homes and businesses were leveled in a matter of minutes, and millions felt the tremors.