By STACY LIBERATORE, US SCIENCE & TECHNOLOGY EDITOR
Published: 23:56 BST, 27 August 2026 | Updated: 07:03 BST, 28 August 2026
A disaster similar to the one that devastated Nepal could strike parts of the US, where collapsing mountainsides can unleash giant waves and send torrents of mud tearing through communities.
Wednesday's deadly flash flood in Nepal was likely triggered when an enormous chunk of glacier broke away and plunged thousands of feet into the valley below, according to an initial scientific assessment.
Researchers have spent years monitoring two parts of the US where a sudden mountainside collapse could trigger a tsunami or unleash a deadly mudflow.
'Alaska has much of the same ingredients for hazard cascades that occur in Nepal and surrounding countries,' Marten Geertsema, an adjunct professor of earth sciences at Canada's Simon Fraser University, told the Daily Mail. He explained that thawing frozen ground can weaken mountainsides, while retreating glaciers can remove the ice that once supported steep slopes.
Geertsema and 13 other scientists warned in 2020 that an unstable slope at Barry Arm, in Alaska's Prince William Sound, could collapse into the water and trigger a catastrophic tsunami. At the time, they considered a landslide-generated tsunami 'likely within 20 years.'
Washington's Mount Rainier, an active, heavily glaciated stratovolcano looming over more than 3.3 million people across the Seattle-Tacoma metro area, also has ice-covered slopes capable of unleashing deadly torrents of mud and debris with little warning.
More than 90,000 people are estimated to live within the mapped danger zones for volcanic mudflows known as lahars. These powerful mixtures of water, rock, mud and debris resemble churning wet concrete as they rush downstream, and some can begin without a volcanic eruption.
Models suggest a large lahar could reach residential areas outside Mount Rainier National Park within 15 to 60 minutes of starting, depending on the location.
Nepal's devastation (pictured) offers a warning for some American communities, where unstable mountainsides could give way to towering waves and deadly torrents of mud
Wednesday's deadly flash flood in Nepal was likely triggered when an enormous chunk of glacier broke away and plunged thousands of feet into the valley below
More than 360 people have died and more than 1,400 remain missing across Nepal and Tibet following Wednesday's disaster.
The US Geological Survey (USGS) identified a glacier collapse and debris flow that produced a seismic signal initially mistaken for an earthquake.
The disaster illustrates a 'hazard cascade,' where one collapse sets off destruction far downstream.
