1,000ft tsunami threat to US as experts reveal risk zones

These towering waves, some capable of exceeding a full 1,000 feet in height, aren’t the kind triggered by undersea earthquakes. Instead, they can form when the sides of mountains, glaciers, or volcanic slopes collapse suddenly into the sea. This then displaces millions of tons of water in an instant. That water has to go somewhere - and it often ends up on land. Researchers say such events, while rare, have happened before. And may very well happen again (Picture: USG)

Most tsunamis are frightening enough, of course. But mega-tsunamis? They're in a league of their own. They're capable of reaching unimaginable heights, rushing inland at incredible speeds and leaving little to almost no time for warning. One historic example took place in 1958 at Lituya Bay in Alaska. There, an earthquake-triggered landslide sent a huge 90 million tons of rock crashing into the water, launching a wave over 1,700 feet high. It’s still the tallest wave ever recorded (Picture: Getty Images)

More than six decades later, expert geologists are watching Alaska very closely once again. As warming temperatures melt glaciers and destabilize frozen slopes, the risk of another massive landslide is growing. In 2020, scientists raised concerns over the retreat of Barry Glacier, warning that a sudden collapse could produce a wave that would absolutely devastate the nearby Prince William Sound region (Picture: AP)

Further south, Hawaii holds a rather frightening prehistoric reminder. Around 100,000 years ago, a wave estimated to be in excess of 1,000 feet high struck the island of Lanai. Fossils from marine life were later found high above sea level - evidence that a gigantic wave once washed across the land. Researchers believe the disaster may have been caused by a sudden volcanic landslide. Hawaii’s steep undersea slopes and volcanic geology mean it’s still at a sizeable risk. If a portion of a volcano collapsed into the sea today, it could be catastrophic. Entire communities might well be caught off guard by a fast-moving wall of water (Picture: Getty)

The Atlantic coast isn’t immune either. Scientists have long debated the potential danger that's posed by Spain’s volatile Cumbre Vieja volcano, which is located on the small Canary Island of La Palma. If a future eruption caused one side of the volcano to shear off and plunge into the ocean, simulations suggest the resulting tsunami could travel across the Atlantic and strike the east coast of America. Though plenty of geologists argue that the scenario is a little unlikely or even overblown, it's an idea which has captured public imagination and prompted calls for more research into long-distance tsunami risks (Picture: USG)

Perhaps the most pressing tsunami threat to North America comes not from far-off volcanoes or prehistoric landslides, but from the Pacific Northwest. 'The Cascadia Subduction Zone', a 600-mile fault line that stretches from Northern California all the way up to British Columbia, is capable of producing both massive earthquakes and devastating tsunamis that affect the US, Canada, and potentially even Central America and beyond (Picture: Google Earth)

The last major rupture happened there way back in 1700. In a new study published in the Proceedings of the National Academy of Sciences, experts say there’s around a 15% chance of a magnitude 8.0 or higher earthquake happening again at some point in the next 50 years. A wave generated by such a quake could reach coastal cities within 15 to 30 minutes, leaving little time to evacuate and escape. One piece of in-depth research predicted that coastal land in some areas could sink by over six feet during such an event, worsening the damage from flooding and making land recovery incredibly difficult or even impossible (Picture: Getty)

The sheer size of a potential mega-tsunami makes it hard to prepare for. A 1,000-foot wave isn’t something you can easily outrun. But experts say early detection, evacuation drills and resilient infrastructure can make a life-saving difference. 'People think these events are science fiction,' one hazard analyst said. 'But we have geological records that prove they’ve happened. And climate change is increasing the risk factors.' Some communities are investing in better early warning systems, while others are mapping escape routes and educating residents on how to respond (Picture: Getty Images)

Whether it’s melting glaciers, volcanic instability or seismic zones, the ingredients for a mega-tsunami already exist. While the chances of one happening tomorrow are pretty small, the consequences would be catastrophic. Scientists hope that by studying past events and monitoring unstable regions, we can prevent history from repeating itself. The threat may be remote. But the wave, if it comes, won’t be (Picture: Getty Images)