A massive rockfall in an Alaskan fjord triggered a record-breaking tsunami last year, with a wave towering 481 meters high, surpassing the CN Tower’s highest observation deck, a recent study reveals. The study, led by Dan Shugar, an associate professor at the University of Calgary, emphasizes the immense risk posed by such catastrophic events, particularly in British Columbia.
The research, published in Science, highlights that the tsunami near the Alaska-B.C. border was a result of a glacier’s rapid retreat that diverted the landslide’s path. It warns that with ongoing climate change and the expansion of infrastructure and tourism, the threat of landslide-induced tsunamis in fjords is escalating.
The study details how a 64 million cubic meter landslide plunged into Tracy Arm Fjord on August 10, 2025, creating a wave with a remarkable run-up of 481 meters. Fortunately, the lone cruise ship present in the fjord at the time was not in the wave’s trajectory, averting a potential disaster.
The researchers stress the importance of monitoring and assessing the risks posed by unstable slopes to prevent future tragedies. They also point out the significance of early warning systems, citing precursory seismic activity detected before the rockfall event.
While acknowledging the existing hazard assessments by institutions like the Geological Survey of Canada, the researchers urge policymakers to consider a broader national strategy to address the growing threat of tsunamis in fjords. The study serves as a stark reminder of the potential dangers posed by natural events and the need for proactive measures to safeguard coastal communities and infrastructure.
