A colossal megatsunami, triggered by a landslide in Alaska last summer, has emerged as the second highest wave ever recorded, highlighting the critical dangers posed by climate change-induced glacier melt. The event, which devastated a remote fjord in southeast Alaska, has raised urgent concerns among scientists about the increasing frequency of such phenomena in the region.
A Catastrophic Event Unfolds
In August 2025, the tranquil waters of Tracy Arm Fjord were violently disturbed as approximately 64 million cubic metres of rock—equivalent to 24 Great Pyramids—plummeted into the sea, generating a wave that soared nearly 500 metres high. This powerful surge went largely unnoticed at the time, occurring in the early hours of the morning, which spared tourist cruise ships from potential catastrophe. “We know that there were people that were very nearly in the wrong place,” said Dr Bretwood Higman, an Alaskan geologist who witnessed the aftermath. “I’m quite terrified that we’re not going to be so lucky in the future.”
Understanding Megatsunamis
Megatsunamis are unique in their formation, typically resulting from landslides—either triggered by earthquakes or loose rock—plummeting into water bodies. Unlike traditional tsunamis, which can travel vast distances in the open ocean, megatsunamis tend to be localised events that dissipate rapidly. The largest megatsunami on record occurred in the 1950s, exceeding 500 metres. The recent event in Alaska is now positioned as a stark reminder of the potential for devastating waves in the face of geological instability.
Dr Higman visited the site shortly after the landslide and noted the extensive destruction. “I found broken trees littering the mountainside, hurled into the water, and vast swathes of scarred rock stripped of soil and vegetation,” he remarked, emphasising the dramatic impact of the event.
The Climate Connection
New research published in the journal *Science* indicates that climate change is exacerbating the conditions that lead to such catastrophic landslides. As glaciers retreat, they no longer support the rock faces that can collapse into fjords. Dr Stephen Hicks from University College London explained that the melting ice had previously stabilised the rock, and its absence allowed for the sudden and dangerous descent of material into the water. “More people are now going to remote areas—often these tourist cruises are going to see the natural beauty of the area to actually learn more about climate change—but they are also dangerous places to be,” he warned.
The scientists involved in the research are calling for increased monitoring of areas in Alaska that may be vulnerable to similar events. The potential for more frequent megatsunamis—possibly ten times as frequent as in previous decades—poses a serious threat to both the environment and human safety.
Vigilance and Safety Measures
In response to the heightened risks, several cruise companies have opted to halt operations in Tracy Arm, prioritising passenger safety over the allure of the region’s stunning scenery. This precaution reflects a growing awareness of the dangers that accompany the beauty of Alaska’s glacial landscapes.
Dr Higman emphasised the urgency of addressing these risks. “At this point, I’m pretty confident that these are increasing not just a little bit, but increasing a lot,” he stated, underscoring the need for proactive measures to protect both residents and tourists in these vulnerable areas.
Why it Matters
The recent megatsunami serves as a stark reminder of the interconnectedness between climate change and geological hazards. As our planet warms and glaciers continue to recede, the likelihood of such catastrophic events will only rise, posing significant risks to coastal communities and tourists alike. This incident not only highlights a pressing environmental issue but also calls for immediate action to safeguard lives in these remote yet breathtaking landscapes. The implications are clear: understanding and mitigating the risks associated with climate change must become a priority for both scientists and policymakers to prevent future disasters.
