Imagine a wall of water, hundreds of miles per hour, towering a third of a mile high, crashing across the ocean. That’s the terrifying force of a mega-tsunami.
Unlike regular tsunamis triggered by earthquakes, mega-tsunamis are usually caused by massive landslides or volcanic eruptions.
In the U.S., Alaska, Hawaii, and the West Coast face the highest risk due to their active volcanoes, unstable slopes, and earthquake zones.
Scientists are still studying traces of a mile-high mega-tsunami caused by an asteroid during the age of dinosaurs. It’s believed the wave started at 2,000 feet near the impact and dropped to 150 feet as it hit the Americas.
More immediate concerns lie with potential mega-tsunamis from areas like Cumbre Vieja in the Canary Islands—but many experts doubt it will produce such a wave, despite past eruptions.
Alaska
A massive granite landslide in Alaska—2,400 by 3,000 feet and weighing 90 million tonnes—triggered a record-breaking 1,719-foot mega-tsunami, the largest ever recorded. NASA compared it to dumping eight million dump truck loads into the ocean.
