Unexpected Tsunami in Southeast Alaska: A Close Call for Kayakers
On August 10, 2025, Sasha Calvey and her companions faced an unforeseen natural phenomenon while on a kayaking expedition in Southeast Alaska. Early that morning, sounds resembling a deep waterfall alerted Calvey to an impending danger, prompting her to check outside their tent.
“Everything in my gut told me to check outside,” Calvey said.
What they discovered was alarming: 15-foot waves had stormed the beach, forcing water into the nearby forest and scattering their gear. Fortunately, the tsunami struck at low tide, sparing them from potentially being swept into the ocean.
The tsunami, they later learned, originated from a massive landslide about 30 miles away in Tracy Arm fjord. This area, situated south of Juneau, saw a landslide triggered by the retreat of the South Sawyer Glacier. Such glacial retreats are increasingly linked to landslides.
Remarkably, the tsunami ascended 1,580 feet on nearby mountains, marking the second-highest run-up ever recorded. As it traveled along the fjord, it left a trail of destruction that extended to the beach where Calvey’s group camped.
In recent years, Alaska has seen a surge in landslide-induced tsunamis. A significant example occurred in 2015 at Taan Fjord with a 630-foot run-up. Another looming threat exists near Barry Glacier, where a landslide could potentially unleash a tsunami greater than Tracy Arm’s.
Researchers and local stakeholders are actively seeking solutions to mitigate these risks, especially as receding glaciers increase the likelihood of such events. The safety of nearly 2 million annual visitors to Alaska, including those on large cruise ships, is at stake.
Calvey noted that while researching her trip, she found warnings about tsunamis linked primarily to earthquakes, such as the 1958 event in Glacier Bay. However, the threat from glacially-triggered landslides was not mentioned, something she hopes will change.
Meanwhile, tour operators and community leaders are grappling with the implications of these natural hazards. Cruise lines have already begun adjusting their routes to avoid areas like Tracy Arm. Communities like Yakutat are working with scientists to understand and prepare for potential geohazards.
As the climate continues to alter landscapes, the need for comprehensive monitoring and early warning systems becomes increasingly apparent. Scientists like Bretwood “Hig” Higman and Jackie Caplan-Auerbach are at the forefront of this research, aiming to better predict and prevent disasters in these vulnerable regions.
Original Story at www.hcn.org