The height of the mega-tsunami that swept along Tracy Arm was 481 meters, almost one and a half times the Eiffel Tower. On August 10, 2025, it happened at 5:26 in the morning, and fortunately at that time, no cruise ship was in the fjord in the American state of Alaska, northwest of Canada, which nevertheless attracts thousands of tourists every summer.
No one witnessed this extraordinary event, but scientists have been able to reconstruct the causes and published their analysis in the journal Science on Wednesday, May 6.
In the two months before the landslide, the glacier at the bottom of the fjord had retreated by 500 meters due to abnormally high temperatures. This created a corridor through which the rock wall was able to collapse into the water, causing the mega-tsunami.
Researchers also discovered that thousands of small seismic shocks had emanated from the area in the days preceding the slope collapse. This could fuel an early warning system. However, such a system doesn’t exist yet, insist scientists, who believe that all Arctic fjords – from Alaska to Greenland and Norway – should be subject to increased monitoring. Climate change is making glaciers unstable, and mega-tsunamis in fjords are likely to increase.
Read also: Arctic glaciers, current situation.
