{"id":1564,"date":"2026-09-07T16:46:04","date_gmt":"2026-09-07T16:46:04","guid":{"rendered":"https:\/\/flatplanplus.io\/bbc-sciencefocus\/?p=1564"},"modified":"2026-09-07T16:46:05","modified_gmt":"2026-09-07T16:46:05","slug":"can-and-will-happen-a-deadly-tsunami-from-the-sky-could-soon-hit-the-us-warn-experts","status":"publish","type":"post","link":"https:\/\/flatplanplus.io\/bbc-sciencefocus\/2026\/09\/07\/can-and-will-happen-a-deadly-tsunami-from-the-sky-could-soon-hit-the-us-warn-experts\/","title":{"rendered":"‘Can and will happen\u2019: A deadly \u2018tsunami from the sky\u2019 could soon hit the US, warn experts"},"content":{"rendered":"\n
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Natural disasters<\/p>\n\n\n\n

\u201cCan and will happen\u201d: A deadly \u2018tsunami from the sky\u2019 could soon hit the US, warn experts<\/h1>\n\n\n\n

Nepal’s deadly flash flood could be a preview of what’s coming to Alaska and other US mountain regions<\/p>\n\n\n\n

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By Jessica McAllen<\/p>\n\n\n\n

–<\/p>\n<\/div>\n<\/div>\n\n\n\n

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Photo credit: Getty<\/figcaption><\/figure>\n<\/div>\n<\/div>\n\n\n\n

Late last month, a wall of water, mud and debris \u2013 likely triggered by a glacial collapse high in the Himalayas \u2013 tore through villages and hydropower sites along the Nepal-China border. At least 1,287 people are known to have died after the flash flood, with 5,000 more still missing.<\/p>\n\n\n\n

The disaster may be a warning of what\u2019s to come. Experts say it\u2019s a matter of when, not if, another deadly \u2018tsunami from the sky\u2019 strikes one of the world\u2019s icy mountain regions \u2013 including in the US.<\/p>\n\n\n\n

In fact, just last year, Alaska’s Tracy Arm fjord was hit by a landslide-triggered wave taller than the Eiffel Tower.<\/p>\n\n\n\n

The 481-metre (approx 1,578 feet) \u2018mega-tsunami\u2019 \u2013 the second-highest ever recorded \u2013 struck at 5:26am, before tourist ships had entered the area. Had it happened just a few hours later, the consequences could have been devastating.<\/p>\n\n\n\n

The only people known to have been nearby were three kayakers camping along the fjord, who had an extraordinary escape.<\/p>\n\n\n\n

\u201cWe scrambled out of our tent and were stunned to find our entire camp obliterated by a tsunami,\u201d they later wrote on a GoFundMe<\/a> page set up to replace their lost equipment.<\/p>\n\n\n\n

The trio survived the wave and were later spotted by a passing yacht, which brought them to safety.<\/p>\n\n\n\n

They were lucky to escape \u2013 but some scientists warn it\u2019s only a matter of time before someone isn\u2019t.<\/p>\n\n\n\n

Prof Bill McGuire<\/a>, a climate scientist and professor emeritus at University College London, says glacier collapses pose a growing danger to communities below ice-covered mountain regions.<\/p>\n\n\n\n

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The aftermath of the recent flash floods and mudslides along the Trishuli River in Nuwakot, Nepal. Photo credit: Getty<\/figcaption><\/figure>\n\n\n\n

\u201cThe event isn\u2019t only a sign of the times, but a pointer to the future,\u201d he says. \u201cIt is a threat that is only going to get bigger as the planet gets hotter.\u201d<\/p>\n\n\n\n

And it’s not just people who live in these mountainous regions who are at risk. Tourists, including those aboard cruise ships, could also find themselves in the path of these disasters. <\/p>\n\n\n\n

So which places are most vulnerable \u2013 and is there any way to know when the next one will hit?<\/p>\n\n\n\n

Why the US can expect more mega-tsunamis<\/h2>\n\n\n\n

Although a landslide is suspected of triggering the flash flood in Nepal, scientists don\u2019t yet know whether climate change or regional warming played a role.<\/p>\n\n\n\n

\u201cIt is not obvious that this is the case, and it will take some time to figure out,\u201d says Patrick Lynett<\/a>, a professor of civil and environmental engineering at the University of Southern California. \u201cPotentially, changes to the glacier conditioned the area for a landslide, or it may have just been a massive landslide with a glacier sitting above it.\u201d<\/p>\n\n\n\n

That uncertainty reflects just how complicated these disasters can be. Climate change is only one factor among many, says Alton Byers<\/a>, a research scientist and mountain geographer at the University of Colorado Boulder\u2019s Institute of Arctic and Alpine Research.<\/p>\n\n\n\n

\u201cThey are certainly related to the impacts of a warming planet and cryosphere,\u201d he says. \u201cBut they\u2019re also influenced by the dynamic geology of mountains, gravity, tectonic activity, and people settling in floodplains.\u201d<\/p>\n\n\n\n

But elsewhere, scientists have found a clearer connection between a warming climate and these extreme events. Alaska\u2019s Tracy Arm mega-tsunami last year is one example.<\/p>\n\n\n\n

\u201cAfter some detailed work it became clear that the rapid retreat of a glacier set the scene for the huge slide and the following mega-tsunami,” says Lynett.<\/p>\n\n\n\n

There are several ways warming can increase the danger. McGuire says rapidly melting glaciers can destabilise mountain slopes, while rising temperatures can thaw the permafrost that helps hold them together.<\/p>\n\n\n\n

Put simply, permafrost is a combination of perpetually frozen ground, rock, soil, debris and ice found in high-altitude alpine regions.<\/p>\n\n\n\n

The devastation caused by the Nepal mega-tsunami. Credit: Getty<\/figcaption><\/figure>\n\n\n\n

In Alaska, McGuire adds, rapid ice loss can also remove enormous amounts of weight from the crust below, allowing faults to move and potentially increasing the risk of earthquakes. \u201cIn a circular manner, quakes caused by ice loss have the potential to trigger glacier collapse and breach meltwater lakes.\u201d<\/p>\n\n\n\n

All of this means glacier collapses are becoming a growing threat to people living downstream of high mountain regions, McGuire says, particularly where there are large amounts of snow and ice. \u201cThis includes Alaska and some of the Rockies, the European Alps and \u2013 especially \u2013 the Himalayas.\u201d<\/p>\n\n\n\n

Similarly, Lynett expects events like Alaska\u2019s mega-tsunami to become increasingly common.<\/p>\n\n\n\n

\u201cTracy Arm-type events will continue to happen, seemingly at an increasing rate, in fjords and other water bodies with rapidly retreating glaciers.\u201d<\/p>\n\n\n\n

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