In July 1958, an 8.3-magnitude earthquake at the Fairweather Fault rocked Alaska’s southern coast. The ground-shaking event caused a massive landslide at nearby Lituya Bay, which triggered a devastating tsunami that ripped through the narrow body of water and killed five people.
The colossal wave leveled trees on the steep slopes surrounding the bay up to a maximum height of 1,719 feet (524 meters) above sea level — higher than New York’s Empire State Building (which stands at 1,454 feet, or 443 m). This is known as the runup height, or the height the wave reaches after it makes landfall.
“It is the largest wave ever recorded and witnessed by eyewitnesses,” Hermann Fritz, a professor of civil and environmental engineering at the Georgia Institute of Technology who specializes in tsunamis and hurricanes, told Live Science. There have likely been larger waves in Earth’s history, which can be inferred from geological deposits, but these are open to interpretation, he added.
Fritz was the lead author of a study published in 2009 in the journal Pure and Applied Geophysics(opens in new tab) that recreated the Lituya Bay tsunami using a specialized 1:675 scale laboratory tank mimicking the shape of the bay. The team found that the maximum height of the wave responsible for leveling the trees was around 492 feet (150 m) tall, which makes it taller than any wave crest recorded on Earth.
For the tsunami to reach this height, the landslide that triggered it would have likely dumped around 1.1 billion cubic feet (30 million cubic meters) of rock into Lituya Bay, the researchers estimated. But while the extreme scale of the landslide provided the force to create such a massive wave, the shape of the bay is the real reason why the wave was so tall, Fritz said.