Study Confirms Alaskan Landslide Caused 1,500-Foot Wave in Remote Fjord Last August

A new study confirms that a landslide in Alaska triggered a megatsunami last August that pushed water more than 1,500 feet up the sides of a fjord near Juneau. The megatsunami sent a wall of water surging high up the fjord walls in an event that went largely unnoticed at the time. Npr reported the details in a story published on May 9, 2026, and heard on Weekend Edition Saturday.

Researchers say more monitoring is needed to prevent future catastrophes. The confirmation comes from analysis that definitively links the landslide to the massive wave. Rebecca Hersher reported the findings for Npr.

The story appeared as part of the network's Weekend Edition Saturday broadcast. The event took place in a remote fjord near Juneau, where the topography amplified the landslide's impact into a megatsunami. Scientists examined evidence from the site to reach their conclusions about the sequence of events.

Last August's landslide dislodged a massive volume of rock and debris directly into the water. That sudden displacement generated the wave that climbed more than 1,500 feet up the opposing slopes. The scale of the megatsunami underscores the potential for similar events in Alaska's glaciated and seismically active terrain.

Researchers emphasized that without better monitoring of unstable slopes, comparable disasters could occur with little warning. Npr reported that the study provides the clearest picture yet of how the landslide initiated the megatsunami. The findings highlight the importance of ongoing geological surveillance in vulnerable coastal areas of Alaska.