In a concerning revelation, a recent study highlights the alarming pace at which glaciers in Alaska’s Denali National Park are melting, intensifying the risks associated with coastal rockslides and mega tsunamis. The research underscores an urgent need to address the escalating dangers posed by our changing climate, particularly in areas frequented by cruise ships.
The Tsunami That Shook Alaska
Last year, a mega tsunami struck the Tracy Arm fjord in southeast Alaska, reaching a staggering height of 481 metres (1,578 feet) following a catastrophic rockslide linked to climate change. This event, which marked the world’s second-tallest tsunami in recorded history, was triggered by a landslide that occurred on 10 August 2025, when a massive volume of rock collapsed onto the South Sawyer glacier.
The timing of the landslide was particularly perilous. Just hours after the disaster, two cruise ships, each capable of carrying over 100 passengers, were scheduled to navigate the fjord. Fortunately, no casualties were reported, but the potential for tragedy was dangerously high. Dennis Staley from the US Geological Survey described the tsunami as “a historic event,” noting the close call for vessels and passengers in the area.
Rising Risks in a Warming World
The study, led by geomorphologist Dan Shugar from the University of Calgary, reveals that the retreat of glaciers due to rising summer temperatures is significantly increasing the likelihood of such catastrophic events. Researchers determined that the landslide, which generated the tsunami, would likely not have occurred without the rapid glacier retreat, underscoring the direct link between climate change and geological instability.
The Tracy Arm incident is part of a worrying trend; annual cruise passenger numbers in Alaska surged from 1 million in 2016 to 1.6 million by 2025. As more vessels traverse these treacherous waters, the risks associated with glacier retreat and subsequent rockslides are compounded, creating a perfect storm for disaster.
Call for Enhanced Safety Measures
The findings highlight an urgent need for improved risk management strategies in coastal regions impacted by climate change. Researchers have called for comprehensive monitoring of unstable slopes, realistic tsunami modelling scenarios, and enhanced protective measures for local communities and tourists alike. This is especially vital given the potential for future tsunamis generated by landslides in fjords, which could have devastating impacts on both human life and infrastructure.
In the past decade, Alaska has witnessed several significant tsunamis, including an 18 to 55-metre wave generated by a landslide in Kenai Fjords National Park in 2024, and a 193-metre tsunami in Taan Fjord in 2015. Each incident serves as a stark reminder of the growing dangers posed by our rapidly changing environment.
Why it Matters
The implications of this research extend far beyond Alaska’s fjords. As the climate crisis intensifies, the risk of geological disasters linked to melting glaciers will only increase. This not only threatens the safety of those who navigate these waters but also poses a significant challenge to coastal communities and ecosystems. Immediate action is essential to safeguard lives and livelihoods, as well as to mitigate the broader impacts of climate change that continue to reshape our planet.
