A colossal wave, born from a massive landslide in Alaska, has been identified as the second-highest megatsunami ever recorded. This event, which struck last summer, serves as a chilling testament to the dangers posed by melting glaciers and shifting geological landscapes amid climate change. New research has unveiled the details of this frightening incident, revealing its potential consequences for both the environment and human safety.
The Tsunami That Went Unnoticed
In August 2025, a significant geological event unfolded in the remote fjords of southeast Alaska. A staggering 64 million cubic metres of rock—equivalent to the weight of 24 Great Pyramids—plummeted into the sea, generating a wave that reached an astonishing height of nearly 500 metres. Fortunately, the early morning timing of this disaster spared tourist cruise ships from encountering the monstrous wave, a close call that has left experts like Dr Bretwood Higman, an Alaskan geologist, deeply unsettled.
“We know that there were people that were very nearly in the wrong place,” Dr Higman remarked, expressing concern about the increasing likelihood of such incidents in the future. “I’m quite terrified that we’re not going to be so lucky next time.”
How Megatsunamis Form
Megatsunamis, unlike their oceanic counterparts triggered by seismic activity, are typically localised phenomena caused when landslides—often instigated by earthquakes or destabilised rock—plunge into water bodies. These colossal waves dissipate relatively quickly and usually affect only nearby areas. The largest megatsunami on record occurred in the 1950s, eclipsing 500 metres in height. The recent Alaska wave, however, ranks as the second largest and highlights the increasing geological instability in the region.
Dr Higman, who visited the scene shortly after the wave struck, noted the extensive destruction left behind. Observations included uprooted trees and extensive rock faces stripped bare of their soil and vegetation, stark evidence of the ferocity of nature’s forces.
The Role of Climate Change
Recent research published in the journal *Science* indicates that climate change-induced glacier melt is exacerbating the risks of such catastrophic landslides. Dr Stephen Hicks from University College London explained that the retreating glaciers, which once held up the rocky cliffs, are now allowing previously stable rock formations to collapse into the water.
“We’re seeing a domino effect,” Dr Hicks warned. “As the ice recedes, it exposes the cliff faces, making them vulnerable to sudden and violent failures.” This phenomenon could have dire implications, especially given the growing number of tourists venturing into these remote areas to witness the natural beauty and learn about climate change.
Increasing Risks and Future Implications
Both Dr Higman and Dr Hicks expressed their alarm over the increasing frequency of megatsunamis. Dr Higman stated, “At this point, I’m pretty confident that these are increasing not just a little bit, but increasing a lot—maybe in the order of 10 times as frequent as they were just a few decades ago.” This stark prediction calls for urgent action and heightened awareness regarding the geological hazards in vulnerable regions like Alaska.
In response to the rising dangers, several cruise companies have already begun to reconsider their itineraries, opting to avoid areas like Tracy Arm. This shift reflects a growing acknowledgement of the potential perils that accompany the breathtaking allure of Alaska’s fjords.
Why it Matters
The recent megatsunami in Alaska serves as a powerful reminder of the interconnectedness of our changing climate and geological stability. As glaciers melt and landscapes shift, the dangers posed by natural disasters like megatsunamis are not only increasing; they are becoming more complex and unpredictable. The implications are profound—not just for local ecosystems but also for the safety of those who seek to explore these breathtaking, yet precarious, natural wonders. As we continue to grapple with the realities of climate change, understanding and mitigating these risks must remain a top priority for scientists, policymakers, and the public alike.
