A colossal wave triggered by a landslide in Alaska has emerged as the second largest megatsunami ever documented, serving as a dire reminder of the threats posed by climate change and glacial retreat. This extraordinary event unfolded in August 2025, when 64 million cubic metres of rock tumbled into a remote fjord, generating a wave that soared nearly 500 metres. Experts are sounding alarms over the potential dangers for both the local ecology and the increasing number of tourists drawn to these breathtaking, yet perilous, landscapes.
Catastrophic Event Unveiled
The cataclysmic wave swept through Tracy Arm Fjord, a stunning destination in southeast Alaska, with little public attention at the time. New research has unveiled the scale of destruction, highlighting how the natural beauty of the area can mask significant hazards. An analysis led by a team of scientists revealed that the landslide occurred early in the morning, narrowly averting a disaster involving tourist cruise ships that frequent the fjord.
Dr Bretwood Higman, a geologist who surveyed the aftermath, described the scene as both striking and alarming. “It was a close call,” he remarked, noting that the potential for human casualties was significant. “We know that there were people that were very nearly in the wrong place,” he added, expressing concerns for future visitors.
The Mechanics of Megatsunamis
Megatsunamis, defined as massive waves typically generated by landslides into water, can be devastating but usually remain localised. Unlike traditional tsunamis, which can be spawned by undersea earthquakes or volcanic activity and travel across oceans, megatsunamis dissipate more quickly but can be incredibly destructive in their immediate vicinity.
The largest recorded megatsunami occurred in the 1950s, reaching over 500 metres. The recent event at Tracy Arm, while not surpassing this record, has raised red flags among scientists, particularly as the conditions leading to such disasters are exacerbated by climate change.
The Role of Climate Change
Research published in the journal Science has established a link between climate-induced glacial melt and the increased frequency of landslides in the region. Dr Stephen Hicks from University College London explained that the retreating glaciers, which historically stabilised the rock faces, are now contributing to collapses into the fjord. “The glacier was previously helping to hold up this piece of rock,” he said, noting that its absence allows for sudden and catastrophic failures.
Scientists are particularly concerned about the implications of such events for both local ecosystems and the influx of tourists seeking to experience Alaska’s majestic scenery. “More people are now going to remote areas—often to learn about climate change—and these are dangerous places to be,” Dr Hicks stressed, underscoring the duality of tourism and risk.
Increasing Risks and Future Monitoring
Dr Higman expressed a growing confidence that the frequency of megatsunamis is on the rise, potentially increasing tenfold compared to previous decades. The combination of Alaska’s steep topography, frequent seismic activity, and climate change creates a perfect storm for such disasters.
In light of these findings, experts are advocating for enhanced monitoring of areas susceptible to megatsunami events. Some cruise lines have already decided to halt operations in Tracy Arm due to safety concerns, signalling a shift in how tourism will adapt to these emerging threats.
Why it Matters
The occurrence of this megatsunami serves as a critical warning about the intersection of climate change, geological instability, and human activity. As glaciers continue to recede, the risks associated with landslides and megatsunamis may escalate, threatening both natural habitats and human lives. This situation underscores the urgent need for increased safety measures and monitoring in vulnerable areas, as well as a greater awareness among tourists and local communities about the real dangers lurking beneath the surface of Alaska’s breathtaking landscapes.
