Scientists warn a devastating “mega tsunami” could hit parts of the U.S. within our lifetimes, mainly due to the Cascadia subduction zone — a major fault line stretching from Northern California to Vancouver Island.

If a powerful earthquake occurs, it could cause land to sink up to 6.5 feet, triggering a tsunami capable of wiping out entire coastal towns. “The impacts to land use could significantly increase the timeline to recovery,” said Tina Dura, lead author of new research from Virginia Tech.

There’s a 15% chance of a magnitude 8.0 or stronger earthquake striking Cascadia in the next 50 years. Other regions are also at risk — Alaska could face tsunamis from landslides and melting glaciers, and Hawaii has seen massive waves from volcanic collapses, including one that sent a 1,000-foot wave over Lanai over 100,000 years ago.

All these threats lie within the Pacific Ring of Fire, an area known for intense earthquakes and volcanic eruptions due to active tectonics.

Experts say a major Cascadia quake is overdue, last hitting in 1700. While fear isn’t the answer, preparedness is. “Have a plan, register for local emergency alerts, and become familiar with evacuation routes,” scientists urge.