Cruise ships at high risk as Alaska's melting glaciers trigger megatsunami

A massive landslide that struck a remote Alaskan fjord last summer triggered a tsunami nearly 500 meters high.

This marks the second-highest ever recorded.

Scientists warn that the accelerating rate of glacial melt can trigger many such catastrophic events in the future.

In August 2025, the world’s second-highest tsunami occurred at 5:26 a.m. when around 64 million cubic centimetres of rock (around the size of 24 Great Pyramids of Giza) plunged from a mountainside into Tracy Arm fjord in southeast Alaska.

Following the event, a 481-meter (1,578 ft) wave appeared on the opposite wall, which is even higher than the Eiffel Tower.

Within a minute, the entire collapse occurred.

As per research conducted and published in the Science journal on Wednesday, the tsunami was caused due to the rapid withdrawal of South Sawyer Glacier, which until then, "had been helping to hold up this piece of rock," according to Dr Stephen Hicks from University College London.

The withdrawal of ice led to the collapse of the rock formation into the fjord.

Luckily, no one was hurt in this incident. But researchers mentioned that it was a “close call” as hours later, a sightseeing vessel and a National Geographic tour boat carrying over 100 passengers entered the fjord.

According to research conducted, there is an increasing danger of tsunamis due to changes in the climate, which are causing glaciers to melt and cause landslides. 

There has been a notable increase in annual passengers on cruises, who numbered about 1 million in 2016 but are estimated to be about 1.6 million in 2025. 

Cruise companies have even announced that they will stop taking their ships into Tracy Arm.