A wetter and warmer Alaska means dangerously slippery slopes

Alaska, News, Online, Print

Originally published by High Country News.

An hour before sundown on Dec. 2, Lilly Ford and her family heard a “strange, low rumble” outside of her home in Haines, Alaska. It lasted about a minute as a 600-foot-wide slurry of timber, mud, soil and debris cascaded down a nearby mountain, through a residential area, and into the ocean. “I couldn’t believe the mountain had swept people and houses away just like that — ripped the ground out from under them,” Ford said. “It’s just not something you’d ever anticipate.”

Haines, population 2,500, saw more than 8 inches of rainfall during the first two days of December — a total that topped the monthly average by 2 inches. Hundreds of homes on this mountainous peninsula between two inlets and the Canadian border were damaged by floods and debris flows. About 50 households were ordered to evacuate because of landslide danger, and still others were displaced by flooding. A kindergarten teacher and a local businessman are presumed dead.

Landslides are a growing threat as warm, heavy rainstorms — intensified by climate change — flush rock, soil, trees and debris down slopes onto the land below. In response to deadly landslides across the West, scientists and communities are calling for more resources to better prepare and understand the looming threat. On Dec. 16, Congress heeded that call by passing legislation that will identify the most vulnerable communities and devise emergency plans and warning systems to protect them.

SOUTHEAST ALASKA is one of the wettest places in the United States, with some areas drenched by more than 200 inches of rain a year. Lush old-growth yellow and red cedar, Sitka spruce and Western hemlock crowd the region’s Tongass National Forest, the largest intact temperate rainforest in the world. It’s also snowy: Thrill-seeking skiers and snowboarders from around the world come to Haines for its legendary deep powder. Now, local weather patterns are being reshaped by climate change.

Rising temperatures and increased precipitation make heavy rainstorms — like the one that triggered the landslides in Haines and across Southeast Alaska — more likely, said Rick Lader, a scientist at the Alaska Climate Adaptation Science Center. In the last 50 years, temperatures in the region have risen 2 to 3 degrees Fahrenheit, and precipitation has increased by up to 15%. Lader said observational records reveal that precipitation intensity — the frequency of days with half an inch of rain or more — is also “significantly increasing.”

Storms are intensifying more rapidly as the rising temperatures pump extra water vapor into the atmosphere, said Jennifer Francis, a climate scientist with the Woodwell Climate Research Center. Just off the West Coast, wind patterns and the jet stream steer warm moist air toward Alaska, fueling warm, wet storms in the North, and leaving Western states in the Lower 48 high and dry, Francis said. “We’re probably going to see a lot more of these really bizarre events.”

Warming temperatures and increased precipitation also thaw permafrost in alpine areas and heighten landslide risks. Once-frozen walls of rock, soil and ice are increasingly prone to slumping down mountains — especially during heavy rains— said De Anne Stevens, engineering geology section chief at the Alaska Division of Geological and Geophysical Surveys.

ON DEC. 3, a day after the catastrophic landslides in Haines, the U.S. House of Representatives passed the National Landslide Preparedness Act. The legislation — authored by Rep. Suzan DelBene, D-Wash., in the aftermath of a 2014 landslide in Oso, Washington, that killed 43 people — establishes a federal landslide program with the U.S. Geological Survey. The bill, which passed the Senate in mid-December, awaits the president’s signature. Money from the legislation will fund a federal grant program, expand early warning systems for post-wildfire debris flow and create a database for landslide hazards across the country.

Annually, landslides kill 25 to 50 people in the United States and cause more than $1 billion in damages. “These statistics will only get worse because of climate change,” DelBene said via email. “The tragedy in Oso, and now unfortunately in Haines, highlights how vulnerable many of our communities are.”

While landslides are nearly impossible to predict, there are ways to identify the areas at greatest risk and monitor the most hazardous slopes. Landslides are triggered by a number of weather, geologic or human factors, but America’s most frequent and damaging landslides are induced by prolonged or heavy rainfall, especially in areas with steep slopes, wildfire burn scars, or a history of landslides.

A prototype early warning system is being developed for the Southeast Alaska community of Sitka, where landslides killed three people and destroyed local infrastructure in 2015. Sensors measuring rainfall, pressure and soil moisture content were installed on three mountains near the town, and the data collected from them is monitored by the Sitka Firehall and the Sitka Ranger District. The prototype — a three-year experiment that’s currently in its second year — warns residents when conditions seem likely for a debris flow. During the early December rainstorms, the sensors in Sitka were able to pick up data about storm intensity and moisture levels in mountain top soils while local scientists monitored conditions.

These systems work: Switzerland, for example, has an active debris-flow mitigation program that includes observation stations equipped with data-collecting instruments connected to a multilevel warning system. In 2017, landslide alarms switched on when the Swiss village of Bondo was about to be hit by the largest landslide the community had seen in decades. The mud flow sent huge granite blocks tumbling into the valley, killing eight hikers. But the warning system, installed in 2012, allowed 150 residents to immediately evacuate to safety.

In Alaska, adaptation is more feasible than establishing an expensive network of warning systems, said Gabriel Wolken, a state geologist in Haines. It would require identifying and at-risk sites and educating nearby communities with the help of critical baseline information, including high-resolution topographic maps, climate data, and landslide susceptibility and hazard maps. Funding and support included in the National Landslide Act “would undoubtedly provide some benefits to understanding and adapting to landslides in Alaska,” Wolken said.

Such a database has been on Alaska scientists’ minds since Sitka’s 2015 landslides. That disaster was a wake-up call, said Stevens, the Alaska Division of Geological and Geophysical Surveys section chief. “We’re recognizing that landslides are a very unevaluated hazard within Alaska, particularly in Southeast and Southcentral Alaska, where you have more rugged topography,” she said. “We have such a huge area at risk, with so little data.”

Without detailed maps, and the baseline support data needed to make them, identification of landslide-prone areas will remain insufficient, and any decisions about possible hazards will be much less informed, Wolken said. “Ultimately, that’s what it’s going to take: the money to be able to collect the data, to be able to make the assessments, to even begin to understand what the magnitude of the problem is,” Stevens said. “We really need to do something about this because this is not going to be the last event.”

LIKE MANY ALASKANS, Lily Ford has been deeply affected by the intensified storms and the havoc they wreak on steep, craggy hillsides. There’s a hovering sense of anxiety that could be lifted with better warning systems and preparedness programs.

Ford’s family has lived in Haines for three years. Only recently, however, have they become aware of landslide risks. When she went to sleep on the first of December, she knew heavy rain was forecast. But she had no idea of the destruction it might bring. When she awoke Dec. 2, she discovered her neighborhood road was washed out, her neighbors were without water and parts of town were flooded.

Ford and her neighbors — who live on the side of 3,600-foot Ripinsky Mountain, directly above the small town — were warned to be ready to evacuate later that afternoon, only after the landslide that likely claimed two lives set off near her home. “It’s been unsettling, and I don’t think the town or anyone in it will ever be the same,” Ford said. “I’ve never had to choose what’s most important to take from my home, knowing I might not see my house again.” After a week, they were able to return, but she said her family will likely spend the rest of winter with their bags packed, ready to go. “It has changed me.”

Drowning the derelicts: Yesterday’s boats are today’s problems

Alaska, Beyond Alaska, News, Online, Print

Originally published in High Country News.

The Lumberman, a 107-foot World War II-era steel-hull tugboat, has been floating at the quiet cruise ship dock in Juneau for months, awaiting a watery grave. Abandoned for nearly a decade, the Lumberman was moored in Juneau’s Gastineau Channel in the early 2000s by its last owner, Brenden Mattson. Two years ago, the 192-ton tugboat’s anchor line broke, stranding it on state tidelands and creating a jurisdictional hot potato for city, state and Coast Guard officials as they debated how to dispose of the vessel.

Then, last winter, a high tide and forceful winds pushed the Lumberman from the tidelands. Fearing property damage, the city of Juneau took responsibility for the historic tug and towed it to the cruise ship dock. In late October, Juneau got permission from the Environmental Protection Agency to get rid of the boat: by scuttling it offshore, about 170 miles from the city. This spring, weather permitting, city officials will open a six-inch valve on the ship, allowing it to sink 8,400 feet to the ocean floor.

This is an uncommon way to deal with a common problem in coastal areas: what to do with abandoned and derelict vessels. Hundreds of such boats are strewn along Alaska’s coast, where they can become navigational hazards or dangerously alluring destinations: In 2017, two people who were trying to reach the Lumberman died when their skiff overturned. Abandoned boats can also damage habitat and leach toxic materials, such as lead paint, asbestos and household cleaners, threatening coastal environments. Each West Coast state would need over $20 million to handle the backlog, and close to $5 million annually to address the ongoing problem. On Alaska’s remote shorelines, these costs can double.

There are many reasons a boat may be abandoned: The owner can die or become unable to continue the boat’s upkeep, or the cost of either maintenance or disposal can be prohibitive. “People generally don’t walk away from the nicer boats that have value,” said Matthew Creswell, harbormaster at Juneau’s Docks and Harbors. “They walk away from the boats costing an arm and a leg to get rid of.”

The cost of removal varies by a vessel’s size and location. On Alaska’s expansive coasts, where infrastructure is sparse, prices are particularly high. The Lumberman, for example, could be discarded and hauled to a landfill, or transported by barge to Seattle, but either option would cost between $250,000 and $400,000, Creswell said. Sinking is a bargain in comparison, but it will still cost Juneau Docks and Harbors over $100,000, for towing, removing trash and stripping toxic lead paint from the vessel. “It’s not a common method,” Creswell said. “But in this case with the Lumberman, (scuttling) was the most cost-effective method.”

Juneau discards about a dozen boats annually. Most are smaller than the Lumberman and easier to remove and salvage locally. But long-abandoned boats are piling up: By 2025, Alaska’s fleet will include more than 3,000 vessels between 28 and 59 feet long that are over 45 years old — past the point of a useful life for most boats — according to the Alaska-based McKinley Research Group.

In 2017, cast-off boats caught the attention of the Pacific States/British Columbia Oil Spill Task Force, an intergovernmental group that promotes coordination in addressing oil spills. The task force labeled derelict and abandoned vessels a “critical, emerging issue” and established a work group to explore the problem. “There is a strong sense from everybody who deals with the issue that it is getting worse pretty much everywhere (on the West Coast),” said Hilary Wilkinson, an environmental consultant in Washington who helps lead the task force and chairs its abandoned vessel work group.

The work group recommends that states look to Washington, which is considered to have a model boat-disposal program — one focused on prevention, owner responsibility and generating funds for removal. Any owner who cannot pay for disposal of a derelict, but floating, vessel that’s less than 45 feet long can ask the Washington Department of Natural Resources to remove it for free. The program handles about 20 boats annually, using money collected from vessel registration fees.

Adequate funding is a “major obstacle” for every West Coast state, according to the work group’s findings. Aaron Timian, Alaska’s abandoned and derelict vessel coordinator, said the state is still developing ways to secure funds. In response to mounting issues caused by vessels like the Lumberman, the state passed legislation in 2018 establishing the program that Timian now leads. The law, which requires boats longer than 24 feet to have a title, simplified the impoundment process and added civil penalties and enforcement authority. The paper trail should also make it easier for authorities to track down owners. While it’s too soon to tell if it will be effective, Creswell said, “It’s totally a step in the right direction.”

Climate change intensifies tsunami threat in Alaska

Alaska, News, Online, Print

Originally published in High Country News.

Tucked against glacier-capped mountains, the Begich Towers loom over Whittier, Alaska. More than 80% of the small town’s residents live in the Cold War-era barracks in this former secret military port, whose harbor teems every summer with traffic: barnacle-encrusted fishing boats, sightseeing ships, sailboats, superyachts and cruiseliner monstrosities. This summer, coronavirus travel restrictions put a damper on tourism in the usually buzzing port. Then came warnings of a potentially devastating tsunami.

Whittier residents have been mindful of tsunamis for generations. In 1964, the Good Friday earthquake was followed by a 25-foot wave that crushed waterfront infrastructure, lifting and twisting rail lines and dragging them back to sea. The Good Friday earthquake — which killed 13 people here and caused $10 million worth of damage — still occupies Whittier’s memory.

With tons of rock and rubble precariously perched high above a nearby fjord, ready to crash into the sea, the town’s present is being shaped by both its past and preparations for an uncertain future. This destabilization is being driven by climate change: Tsunamis are becoming more likely in Alaska as hillsides, formerly reinforced by glaciers and solidly frozen ground, loosen their hold on once-stable slopes.

On May 14, an Alaska Department of Natural Resources press release and a public letter from 14 scientists warned locals of a possible landslide-generated tsunami. Alaska has identified three similar events in the past: Tsunamis in 2015 and 1967 occurred in remote areas, while one in 1958 killed two people whose boat was capsized. But the unstable slope in Barry Arm, a narrow steep-walled fjord in Prince William Sound, is vastly more dangerous. The potential energy from a catastrophic slide here is approximately 10 times greater than previous events, the state’s top geologist said in the May press release.

The landslide in Barry Arm has been lurching towards the ocean since at least 1957, when Barry Glacier — which once gripped the base of the mountainside and held back the slope — first pulled its load-bearing ice wall out from under the rocky slope. As the glacier retreated, so did the slope’s support system — dragging the rock face downward toward the ocean, leaving a distinct, zig-zagging indentation in the hillside. Between 2009 and 2015, Barry Glacier retreated past the bottom edge of the landslide, and the slope fell 600 feet. Since 2006, Barry Glacier has receded by more than two miles. Scientists believe the slope is likely to fail within the next 20 years — and could even do so within the year.

Climate change makes land more unstable and increases the risk of landslide-caused tsunamis. As the climate warms, glaciers melt and recede, pulling back from the mountainsides they were hugging. Barry Glacier’s wall of ice — which once held the hillside in place, supporting it against the fjord’s mountains — has thinned, edging away from the rock face, releasing its support and revealing an unstable slope that is slipping downward toward the ocean. Brentwood Higman, geologist and executive director of Ground Truth Alaska, is working with other scientists to research climate change’s impact on landslide-triggered tsunamis. “(These events) are worth worrying about regardless of climate change,” Higman said. “But there are a number of reasons to think climate change makes them a lot more likely.”

As glaciers recede, the land above them also becomes more unstable. The craggy alpine region of south-central Alaska is already thawing dramatically. Once-frozen slabs of rock, dirt and ice are releasing trapped liquids and becoming more prone to sliding down mountains.

Another less-obvious symptom of climate change increases the risk. When there’s more water in the atmosphere, precipitation becomes more intense. Rain, even more than earthquakes, is prone to trigger landslides, Higman said. Climate change will make landslides more likely and more frequent, said Anna Liljedahl, an associate scientist with the Woodwell Climate Research Center. “It’s a new emerging hazard, and that’s why it’s urgent to do an assessment of where we have these unstable slopes and where they are a hazard to people,” Liljedahl said.

Tracking unstable slopes can give local governments time to install warning systems, so scientists are working to identify unstable land, focusing on monitoring landslides near communities in Southeast and south-central Alaska.

In mid-October, Gabriel Wolken, the Climate and Cryosphere Hazards Program manager for the Alaska Division of Geological and Geophysical Surveys, took a helicopter to Barry Arm. From the air, he conducted a lidar survey, using a laser scanner to measure the topography of the slide area in fine detail, calculating how the landslide has moved and changed since June. The data is still being processed. But, there are new rockfalls in the area every time he visits, indicating the area’s instability. “The rock itself isn’t very competent,” Wolken said. “It’s basically falling apart.”

Whittier residents are aware of the risk, said Peter Denmark, who runs a commercial kayaking business in town. “With the people around town, there’s a laissez-faire attitude about it,” Denmark said. Alaskans have “thick skins” when it comes to disasters, he said. “If it’s not tsunamis, earthquakes, volcanoes, forest fires — it’s one thing or another.” Still, Denmark is taking precautions; he avoids the Barry Arm area on kayaking tours.

Kelly Bender and her husband Mike rely on summer tourism in Prince William Sound. From their waterfront office, she charters water taxis, fishing boats, kayaking and sightseeing tours. Before news of the potential landslide broke, Bender said their fleet went into Barry Arm daily. With its scenic location, near glaciers and a popular beach, the state estimates that 500 people could be in the area at any given time during peak tourist season. Bender has changed tour routes, cancelled water taxi trips — even cancelled a planned wedding. “The danger part of it — people are feeling like ‘we know what to do in a tsunami,’” Bender said. “It’s the business part of it that we’re all really, you know, hanging by a thread.” When tsunami warning sirens blare in Whittier, residents know to move swiftly away from the coast and head to higher ground. The state encourages coastal residents to keep a “go bag” filled with emergency supplies and to plan evacuation routes.

While it’s still possible to avert or mitigate many of the worst impacts of climate change, there really isn’t an option to eliminate landslide-generated tsunamis. The state uses howitzer cannons to trigger controlled avalanches in railway and highway corridors, but there’s no easy way to gently coax a colossal land mass off the side of a mountain and into the ocean. “It’s pretty much science fiction,” Higman said. Smaller landslides might be able to be stabilized from the bottom up, but large landslides, like in Barry Arm, “forget about it,” Liljedahl said.

Increasing preparedness, installing a robust monitoring system on and near landslides and creating an effective localized alert system are the best ways to protect communities, she said. Some locals, like Denmark, the kayak outfitter, prefer a quicker approach, however. “My idea was to just blast it down and duck,” he said. “But nobody thought that was a good idea.”