Alaska Mega-Tsunami Raises Alarm for Cruise Ships in Glacier Fjords

A massive landslide in Alaska’s Tracy Arm fjord triggered one of the tallest tsunamis ever recorded, sending water 481 meters—about 1,578 feet—up the opposite wall of the fjord in what scientists are calling a climate-linked near miss for cruise tourism.

The Aug. 10, 2025 event, detailed in a new study published Wednesday in Science, began when more than 64 million cubic meters of rock collapsed into the fjord near South Sawyer Glacier, about 80 miles south-southeast of Juneau. The landslide generated an initial 100-meter breaking wave traveling more than 70 meters per second, followed by a megatsunami that stripped vegetation from the