Cascadia Megathrust Earthquake

The Cascadia Megathrust Earthquake refers to a potential, extremely powerful earthquake that could occur along the Cascadia Subduction Zone, located off the coast of the Pacific Northwest, including parts of the U.S. and Canada. This zone is where the Juan de Fuca Plate is sliding under the North American Plate. Such an earthquake could be magnitude 9 or greater, causing massive ground shaking and tsunamis. Historically, major quakes have occurred every 300 to 600 years, with the last significant event estimated to have happened in 1700. Preparedness is crucial for the regions most at risk.