Scientists are raising alarms over a recent mega tsunami in Alaska, which struck a popular fjord last year, revealing alarming risks linked to glacier retreat and coastal rockslides exacerbated by climate change. The incident, which occurred in August 2025, serves as a crucial warning for the cruise industry and local communities navigating these treacherous waters.
A Historic Tsunami Event
On 10 August 2025, at 5:26 AM local time, a massive rockslide occurred at the South Sawyer glacier, triggering a tsunami that reached a staggering height of 481 metres (1,578 feet) in Tracy Arm fjord. This wave, the second-tallest tsunami on record, dwarfs the height of the Eiffel Tower, which stands at 330 metres (1,082 feet).
The study, published in *Science* and led by geomorphologist Dan Shugar from the University of Calgary, indicates that the landslide dropped approximately 1 kilometre vertically into the fjord, unleashing the immense wave. Fortunately, no casualties were reported at the time of the event, but the fjord is frequented by about three cruise ships daily, alongside numerous other vessels.
Just hours after the landslide, two large tour boats were set to enter the fjord, raising concerns about the potential for disaster. The previous day, thousands of tourists had already passed through the area, highlighting the precarious nature of such popular tourist destinations.
Eyewitness Accounts and Effects
Witnesses reported the tsunami’s effects from as far as 55 kilometres away. Kayakers camping on Harbor Island experienced water surging past their tents, with one kayak swept away. Another observer, positioned in No Name Bay, approximately 50 kilometres from the landslide, described seeing waves cresting at heights of 2 to 2.5 metres, followed by a smaller wave of about 1 metre.
The study details how the tsunami’s unique characteristics, including its height, were influenced by the specific geological features of the fjord. Researchers noted that tsunamis generated from landslides can have significantly higher run-ups than those produced by earthquakes due to the dynamics of confined bodies of water like fjords.
Climate Crisis and Increased Risks
The study underscores the direct link between climate change and the increased frequency of such catastrophic events. The researchers highlight that without the rapid retreat of glaciers, the landslide likely would not have resulted in such a dramatic tsunami. As glaciers continue to recede, the risk of landslides in these vulnerable areas is anticipated to rise, further threatening both local communities and the burgeoning cruise industry.
In recent years, the popularity of Alaska’s fjords among cruise passengers has surged, with figures climbing from approximately 1 million in 2016 to 1.6 million in 2025. This increased footfall into already precarious areas raises pressing questions about safety and preparedness.
The Need for Proactive Measures
Given the increasing incidence of landslide-generated tsunamis, researchers are calling for enhanced monitoring and risk mitigation strategies. This includes systematic observation of unstable slopes, improved tsunami modeling, and stronger protective measures for local communities and tourists alike.
The implications of the Tracy Arm tsunami are significant. Several other notable tsunamis have occurred in Alaska in recent years, including a wave reaching 193 metres in Taan fjord in 2015. These events highlight a concerning trend that demands immediate attention from policymakers, scientists, and the tourism industry.
Why it Matters
The alarming rise in tsunami events related to glacier retreat and climate change poses a serious threat not only to the natural environment but also to human life and economic stability in coastal areas. As climate change continues to reshape landscapes, the need for robust risk assessment and management becomes ever more critical. The Tracy Arm incident serves as a stark reminder that the impacts of climate change are not distant concerns but present realities that require urgent action and awareness.
