Experts fear this quake-maker and say it’s only a question of when it will strike again. It’s gigantic, sits at the bottom of the ocean and stretches for 700 miles. The last time it shifted on January 26, 1700, it caused the largest earthquake in the continental U.S. and a tsunami so powerful it crossed the entire Pacific Ocean and still had enough force to damage villages in coastal Japan.
The Cascadia subduction zone is immense and could cause a 9.0 magnitude earthquake that would be about 30 times stronger than a quake from San Andreas, California’s most well-known fault line. Chris Goldfinger, a geophysicist, says this quake will be different. “The more we learn about it, the less we like it, because it is turning out to be a big hazard as well,” Goldfinger says.