A colossal wave, the second largest of its kind ever documented, surged through a remote fjord in Alaska last summer, unveiling the significant hazards posed by climate change and glacier melt. The event, which has largely flown under the radar until now, was triggered by a massive landslide, indicating a serious need for vigilance in an area where natural disasters are becoming increasingly frequent.
The Scale of the Disaster
In August 2025, a staggering 64 million cubic metres of rock—equivalent to the weight of 24 Great Pyramids—plummeted into the waters of Tracy Arm Fjord. This catastrophic landslide generated a megatsunami that reached heights of nearly 500 metres. Researchers suggest that the incident could have had far more devastating consequences had it occurred during the day when tourism activities were at their peak.
Dr Bretwood Higman, a geologist who visited the site shortly after the incident, described it as “a close call.” He expressed his concerns over the proximity of tourists to such disasters, stating, “We know that there were people that were very nearly in the wrong place. I’m quite terrified that we’re not going to be so lucky in the future.”
Understanding Megatsunamis
Megatsunamis differ from traditional tsunamis, which are typically generated by seismic activity or underwater volcanic eruptions. The former are localized and result from landslides that occur when loose rock or ice collapses into water. Although they dissipate swiftly, their impact is immediate and destructive. The largest recorded megatsunami occurred in the 1950s, measuring over 500 metres, making this recent incident the second highest on record.
After the tsunami, Dr Higman surveyed the aftermath and found a landscape transformed: trees were uprooted, and large areas of rock were stripped bare of vegetation. Alaska’s unique geography—with its steep mountains, narrow fjords, and frequent seismic activity—makes it particularly susceptible to such occurrences.
The Role of Climate Change
Recent research published in the journal *Science* indicates that climate change is exacerbating the risks associated with landslides and megatsunamis. As glaciers retreat due to rising temperatures, they destabilise the rock formations they once supported. Dr Stephen Hicks from University College London noted that the melting glaciers were “helping to hold up this piece of rock,” and their retreat allowed for a sudden collapse into the fjord.
Scientists like Dr Hicks, who have studied tsunamis for decades, are increasingly alarmed. “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 cautioned.
Increased Monitoring and Safety Measures
The potential for megatsunamis appears to be increasing significantly, with Dr Higman estimating that such events may occur ten times more frequently than they did a few decades ago. In response to this alarming trend, researchers are calling for enhanced monitoring of hazardous areas in Alaska that are vulnerable to megatsunami activity.
In light of safety concerns, some cruise lines have already adjusted their itineraries, opting to avoid Tracy Arm for the foreseeable future.
Why it Matters
This latest megatsunami serves as a critical reminder of the interconnectedness of climate change and natural disasters. As glaciers continue to retreat, the risks posed to both local ecosystems and human activities are escalating. The incident highlights the urgent need for increased monitoring and safety protocols in vulnerable regions, particularly as tourism grows in areas often perceived as pristine and safe. The implications for both residents and visitors are profound, marking a pivotal moment in the dialogue surrounding climate resilience and disaster preparedness.
