On a fair mid-July evening, Melenda Lekanof rode in a helicopter over a glacier-ringed inlet north of Yakutat.
A 2,000-passenger cruise ship sat in the middle of the bay, but Lekanof was focused on something else. As the helicopter veered east, she pointed out a ridge marked with deep, vertical gashes. Scientists say the slope has started to destabilize and creep toward the water below.
“That cruise ship is right there. And that mountain, that cliffside, is right there,” said Lekanof, who is Tlingit and Aleut, from Yakutat. “If that slid, the cruise ship is toast.”
The threat isn’t unique to Yakutat’s Disenchantment Bay. Much of Alaska’s southern coast is made up of steep, crumbling slopes above deep, narrow fjords — the perfect recipe for deep-seated landslides so large they can generate waves hundreds of feet high.
Those landslide-generated tsunamis could be catastrophic for people in nearby vessels, including commercial fishermen, tour operators, and passengers in the giant cruise ships that bring about 1.7 million people to Alaska every year.
Public awareness of landslide tsunamis has surged since August of 2025, when the second-tallest tsunami on record hit Tracy Arm, a fjord south of Juneau frequented by cruise ships.
It was early, and no boats had arrived for the day, so no one was hurt. But experts say the near miss highlighted a threat that appears to be intensifying with climate change.
Scientists working on the problem face a long list of challenges. Funding is limited, and Alaska’s sprawling, remote coastline makes identifying and monitoring dangerous slopes an enormous undertaking. On top of that, there is no sure way yet to tell if a slope is about to fail, or to warn people if it does.
Chad Hults, a geologist formerly with the National Park Service who now consults with the agency, said the problem could result in a major loss of life and an environmental catastrophe.
“There’s 4,000 people in the way of an obvious hazard every single day, in multiple fjords across Alaska,” he said. “The likelihood of another event happening, and a cruise ship being in a fjord, is really high.”
Meanwhile, residents and emergency management officials in places like Yakutat worry that there are no clear plans for what to do if a tsunami does take out a cruise ship.
“We don’t have enough people, in every skiff in town, to get up there and help,” said Casey Mapes, who served as chief of the community’s volunteer fire department for 12 years. “You’re going to have a massive loss of life.”
‘The landscape of Alaska is falling apart’
There’s a cliche in the cruise world that spells out the recipe for the perfect Alaska voyage: Three ports and a tidewater glacier.
“They call it ‘getting ice,’” said Alix Pierce, Juneau’s visitor industry director. “It’s like, ‘If I can’t go here to get ice, where do I go?’”
The most sought after ice is in Glacier Bay National Park, but a strict permit system limits entry there to two large ships per day. That leaves other ships to go where there’s little or no regulation — like the Hubbard Glacier in Disenchantment Bay or the South Sawyer Glacier in Tracy Arm, where the 2025 tsunami happened.
The bad news is, experts say some of the same fjords that draw the industry also appear to be where landslide tsunami risk is the highest, and growing.
“We actually are seeing a dramatic increase, maybe on the order of a tenfold increase, in the occurrence of these events,” said Bretwood Higman, a geologist who runs Ground Truth Alaska, an educational nonprofit focused on Alaska’s environment.
Many scientists, including Higman and Hults, see a likely connection to rising global temperatures.
Permafrost high up in the alpine is thawing, leaving coastal slopes without the glue that’s long held them together. At the same time, glaciers are retreating rapidly, exposing new, fragile mountainsides in the process.
“Us geologists have recognized over the last couple decades that the landscape of Alaska is falling apart,” Hults said. “And it’s largely due to climate change.”
There’s a long history of these events in Alaska. The most famous happened in 1958, when an earthquake triggered a massive rockslide into Lituya Bay. The slide created the highest tsunami ever recorded. Two people died on a fishing boat in the bay. About 100 miles northwest, in Yakutat Bay, another three people died while berry picking on an island that partially slumped into the sea.
Still, landslide tsunamis have been rare, historically speaking. And one has yet to sink a cruise ship. Higman said both of those factors make it hard to get people to pay attention.
“I certainly grew up thinking of Lituya Bay as this one-in-a-billion chance, crazy event,” he said. “And now this is happening roughly once a year.”
“That’s something people don’t realize,” he added.
‘Dozens or hundreds of locations’
Alaska’s shoreline sprawls for tens of thousands of miles, and much of its southern reaches hold the key ingredients for landslide tsunamis: strong earthquakes, steep mountains, weak rock, deep water and extreme weather.
“It can happen just about anywhere we have these inlets with retreating glaciers and steep rocky slopes,” said Jill Nicolazzo of the Alaska Division of Geological and Geophysical Surveys. “There are dozens or hundreds of locations.”
State and federal agencies have started surveying the southern coast for slopes that could fail and cause death or damage. But Hults said narrowing the focus to cruise ship hot spots would make the most sense right now.
“They only go to a handful of tidewater glaciers across the state, right?” he said.
Experts say a monitoring system that could help people avoid hazardous areas by informing them about worsening conditions, as opposed to issuing post-slide alerts, makes the most sense for people on the water. That’s because landslide-generated tsunamis can cross fjords and bays in minutes.
But that kind of system would also be a huge lift because maintaining monitoring equipment on remote coastal slopes is expensive and logistically difficult. It’s also possible for every sign to point toward an imminent failure that never happens — or for a slope to fail without any warning at all.
“We can assess where landslides are more likely, but predicting the exact timing of an individual event remains beyond current scientific capability,” Michael Loso, a glacier- and landslide-focused geologist with the National Park Service, said in an email.
State and federal agencies are using remote sensing technology to monitor slopes and active slides throughout parts of the region. But for now, on-the-ground work largely focuses on a single site: Barry Arm in Prince William Sound, where scientists raised the alarm in 2020 about an unstable slope above the Barry Glacier.
Dennis Staley, who runs the project for the U.S. Geological Survey, said lessons learned there could eventually be applied elsewhere. But he thinks that could take years, if not decades.
“So there are things that we could do, but there’s no one simple answer,” he said. “None of it’s easy, and all of it takes time.”
‘There needs to be a plan’
Back in Yakutat, on a foggy afternoon in mid-July, Mark Sappington dodged icebergs as he steered his boat north toward the Hubbard Glacier. The boat jerked from front to back after a large chunk calved off the towering wall of ice, sparking a sizable wave.
“This is no landslide, but there’s a lot of energy going on right here. Can you imagine the side of a mountain, and what that would do?” said Sappington, who has run fishing and glacier viewing tours in Disenchantment Bay for more than three decades.
“I watch for it,” he said. “I definitely watch for it.”
Higman, of Ground Truth Alaska, created a statewide landslide inventory that shows two slow slides near the water in the bay, though he said there could be more he’s missed.
Lekanof had pointed out one of the slides, at Logan Bluffs, from the helicopter. A simulation at that site shows that a major slide could send a huge tsunami across the bay in minutes.
In some parts of the bay, the wave would amount to a large swell that Higman said would be dangerous but potentially survivable. The model shows a “violent breaking wave” moving through the mouth of the bay, where many cruises travel. The tsunami could be over 100 feet tall and “destroy anything in its path,” Higman said.
Depending on the day, the busy inlet draws charter operators like Sappington, fishing boats, and as many as five cruise ships.
Lekanof has played a key role in raising awareness around the risk and bringing experts to town to study it. She said the community would benefit greatly from a monitoring system with some sort of dashboard that could alert mariners to elevated landslide risk.
But she also thinks the tsunami danger calls for an emergency response plan tailored to the worst-case scenario — and that the cruise industry has a responsibility to be involved.
“There needs to be a plan for them and for their rescue,” she said.
The Cruise Line Agencies of Alaska did not respond to multiple requests for comment, and the Cruise Lines International Association did not respond to an interview request. But the international organization said in an emailed statement that safety is the industry’s “highest priority,” and that cruise lines are able to adjust itineraries “when conditions warrant.”
It’s happened before. After the Tracy Arm slide, major cruise lines tweaked their itineraries to avoid the fjord, opting instead for another nearby glacier.
Raymond Reichl, an emergency management specialist with the U.S. Coast Guard, said the agency has not received any “specific feedback directly from the cruise lines as to where that sits in their risk analysis.”
He said the Coast Guard is following research related to landslide tsunamis. But at least for now, he said, the agency has not seen anything that would warrant steps like closing specific waterways, and it has not developed a plan for “events like what happened in Tracy Arm.”
Mapes, the longtime fire chief, is a local history buff. He’s spent years combing through old accounts of tsunamis and other disasters in Yakutat and beyond.
“Look at these pictures of forests laid down,” he said. “Look at these stories of guys washed over spits riding on the face of waves. It’s going to happen again.”
That’s what pushed him to keep raising it with Coast Guard officials at meetings to plan for other mass casualty disasters.
But Mapes said he always felt like “the heckler in the room,” and never got any traction. As he sees it, the most immediate solution would be to ratchet down cruise visitation to one ship per day.
“Nobody wants to hear that at these kinds of meetings,” Mapes said.
