A colossal megatsunami, triggered by a landslide in Alaska, has emerged as the second tallest wave ever documented, underscoring the escalating dangers posed by climate change and melting glaciers. Last summer, the remote fjord of Tracy Arm was struck by a wave nearly 500 metres high, a phenomenon that initially went unnoticed but has since raised alarm among scientists and researchers.
The Catastrophic Event
In August 2025, a staggering 64 million cubic metres of rock—equivalent to 24 Great Pyramids—plummeted into the waters of Tracy Arm Fjord, generating a monstrous wave that wreaked havoc on the landscape. This extraordinary landslide, caused by the destabilisation of a mountain, released immense energy in a matter of seconds, resulting in destruction across the fjord.
Had the incident occurred just a few hours later, tourist cruise ships exploring the region could have been caught in the disaster. Dr Bretwood Higman, an Alaskan geologist, witnessed the aftermath and described the situation as a “close call.” He expressed deep concern, stating, “I’m quite terrified that we’re not going to be so lucky in the future,” emphasising the lurking threats in areas popular with tourists.
Understanding Megatsunamis
Megatsunamis differ significantly from their more common counterparts. These massive waves are generated by landslides, often triggered by earthquakes or the destabilisation of rock, leading to rapid displacement of water in localized areas. In contrast, standard tsunamis, such as those caused by seismic activity underwater, can traverse vast oceanic distances, often resulting in widespread devastation in coastal regions.
The most significant megatsunami on record occurred in the 1950s, surpassing 500 metres in height. This latest event, though monumental, is now recognised as the second largest—an alarming statistic that underscores the potential for future occurrences.
The Role of Climate Change
Recent research published in *Science* provides crucial insights into how climate change is exacerbating the risks of landslides and megatsunamis. Dr Stephen Hicks from University College London noted that receding glaciers, which once provided stability to cliff faces, are now contributing to increased rock collapses. “When the ice retreated, it exposed the bottom of the cliff face, allowing that rock material to suddenly collapse into the fjord,” he explained.
As glaciers melt at an unprecedented rate, the likelihood of similar catastrophic events increases. Dr Higman asserted that the frequency of megatsunamis may have surged tenfold compared to just a few decades ago—a stark warning for those venturing into these natural environments.
A Call for Vigilance
The implications of this megatsunami extend beyond geological concerns; they serve as a critical reminder of the intersection between natural beauty and environmental peril. With more tourists drawn to Alaska’s stunning landscapes—often seeking to understand the impacts of climate change—the risks of encountering such disasters rise. In response to safety concerns, some cruise companies have opted to halt operations in Tracy Arm.
Dr Higman and his colleagues advocate for enhanced monitoring of potential megatsunami hazards in vulnerable regions across Alaska. As our understanding of these phenomena deepens, so does the urgency to protect both visitors and local ecosystems from the growing threats posed by climate change.
Why it Matters
The recent megatsunami in Alaska serves as a harrowing reminder of the profound and immediate impacts of climate change on our planet’s geological stability. As glaciers continue to melt and landscapes shift, the potential for catastrophic events increases, amplifying the need for vigilant monitoring and proactive measures to safeguard both the environment and those who seek to explore its wonders. Understanding these risks is essential for ensuring the safety of future generations and preserving the natural beauty of places like Alaska.
