A major earthquake waiting to strike the Cascadia Subduction Zone isn’t the only natural disaster looming in the Pacific Northwest, new research shows.

When an earthquake rips along the Cascadia Subduction Zone fault, much of the U.S. west coast could shake violently for five minutes, and tsunami waves as tall as 100 feet could barrel toward shore.

A major earthquake in the Pacific Northwest could sink land and expand flood zones, putting thousands more at risk.