When Alaska state engineer Jeff Currey heard about frozen debris lobes inching toward the Dalton Highway, the first thing that flashed in his mind’s eye was the campy 1958 horror movie “The Blob.”
Currey, who worked 21 years for Alaska Department of Transportation and Public Facilities in this capacity, found it a bit absurd.
It didn’t seem plausible to him that a massive, underground mix of rocks, soil and trees was relentlessly inching toward the highway 200 miles north of Fairbanks near Coldfoot. The 414-mile highway runs from Fairbanks, Alaska to Prudhoe Bay, Beaufort Sea.
“Frankly, we poo-pooed it,” Currey said about the time a decade ago when transportation officials were first alerted to the lumbering mass.
He summed up the consensus among highway officials back then: “OK. It’s there and moving slow; nothing for us to be concerned about.”
But the more Currey and other engineers considered the unrelenting characteristics of one particular blob—identified as Frozen Debris Lobe A—they soon understood the dire consequences facing the Dalton and the Trans-Alaska Pipeline, which the highway was built to service in 1974 and parallels the road. They crush and engulf everything they come across.
Currey found it most concerning that Debris Lobes A and more than a dozen others were increasing in speed. This was unharnessed, and accelerated by the warming temperatures triggered climate change. Speed in the case of debris lobes may be relative when talking about a couple of feet of movement a month and the road and pipeline are still a mile away, in some cases, but there’s nothing that can stop the lobes.
The snickering stopped when it became obvious that Debris Lobe A was eventually going to wipe out a section the Dalton.
“Now it’s serious,” Currey said.
The threat has Currey and the transportation department keeping a watchful eye on the lobes, though he says he doesn’t “dwell” on them. The transportation department has contributed more $200,000 to scientists studying the brain lobes. Academics, the oil industry, and other federal agencies have joined Currey and the department to assess the threat, and to work out solutions.
Alyeska Pipeline Service Company is a consortium of oil companies that owns the Trans-Alaska Pipeline System. It has pledged $100,000 to help fund investigations into the pipeline’s lobes.
Michelle Egan, a spokeswoman for Alyeska, said the company is working with other agencies and organizations to monitor natural hazards and changing environmental conditions in Alaska.
“Alyeska’s integrity management program includes a team of engineers that specialize in monitoring and protecting the system from external forces, including frozen debris lobes,” she said. “Mitigations that protect the integrity of TAPS are under consideration and will be worked with these partners as well as regulatory agencies.”
Egan declined further information on the mitigation measures.
Climate Change has Unleashed the Lobes
According to the Fourth National Climate Assessment, released in 2018, Alaska is one the fastest-warming regions on Earth. By the middle of the century, the state’s highest daily maximum temperature could increase between 4 and 8 degrees Fahrenheit.
The warming has put the pipeline, which carries 20 million gallons of crude oil a day, and the Dalton, which acts both as a lifeline for remote Arctic villages and the supply link to the oil fields, in jeopardy.
Alyeska is involved in projects to install ground-chillers below an elevated section of the pipe 57 miles north of Fairbanks to stop the thaw that has deformed several braces. Alyeska also works along a northern segment of the pipeline for protection against the Sagavanirktok River’s increasing flooding.
At the same time, the state transportation department has spent millions over the past five years to raise six sections of the Dalton so that the roadway is above flood levels where it hugs the pipeline’s route.
Now, climate change has opened the debris lobes of the earthen behemoths and hastened their movement.
43 frozen debris pockets were identified by scientists and state transportation officials along the Dalton Highway in the southern Brooks Range. Twenty-three are uphill, in some cases less than a mile from the road and pipeline. They are also sliding faster each year. However, the lobes cannot be stopped by any mitigation measures, such as installing ground chillers to stop permafrost melting or building flood barriers to deflect flood waters.
Researchers, including the U.S Geological Survey and University of Alaska, first described the effect of global warming on the lobes in a 2012 study that concluded “frozen debris-lobes have responded to climate change by becoming increasingly active during the last decades, resulting in rapid downslope movement.”
Margaret Darrow, a professor of geological engineering at the University of Alaska Fairbanks, is one of the principal lobe researchers who has measured the movement of the lobes since 2012, noting in one early study the lobes demonstrate “characteristics of increasing instability.” In the succeeding years, she said in an interview, that hasn’t changed as the pace of the lobes continue to quicken.
“Given the trend that we have right now, we don’t know what it means for the future,” she said.
Ron Dannen is a geohydrologist from the Alaska Department of Natural Resources. He was one of the report’s authors along with Darrow. Ron has been exploring the lobes over a decade, hiking over the lumps and digging into them with a variety of devices.
He is concerned about what he sees.
“These things are an unstoppable force,” he said. “They are coming awful close to the road and pipe; and we simply do not know how to stop them. Right now they will destroy the road and pipe.”
In the face of that awesome power, “to do nothing would jeopardize the highway and pipe,” said Daanen, who calls the lobes an “incredible combination of physics and geology.”
Still Years Away
While the destruction of the road and pipeline appears inevitable, it’s not imminent. Daanen, scientists, and officials from the state have managed to temper panic by pointing out that the lobes still have years before they reach the highway or the pipeline.
“That doesn’t mean there is a sense of relief,” Daanen said. “It means now is the time we have to make finding answers a priority.”
Some of those answers could come next year because Frozen Debris Lobe A—er child of debris lobes—is about to thump into an abandoned section of the highway.
Keep Environmental Journalism Alive
ICN provides award winning climate coverage without charge or advertising. We are dependent on donations from readers like yours to continue our work.
You will be redirected to ICN’s donation partner.
Lobe A measures approximately three-quarters mile in length, is more than 600 feet wide, and is 65 feet deep. There’s no calculating the energy it carries, but it topples trees, shucks aside boulders, devours the landscape and mangles scientific instruments left in its path. Researchers estimate that it could dump 22,000 tons of debris onto the roads.
“When we explained this problem, we told them that this thing is faster than you think and it’s bigger than you think,” Daanen said about a meeting with transportation officials in 2013.
The lobe is one of eight being closely monitored and is believed to have moved out of its catchment basin around 15 years ago. The lobe was slipping towards the highway and pipeline at an average of 16 feet per year according to measurements made using everything, from GPS devices to stakes pounded into ground. But it’s been accelerating ever since. Between 2019-2020, the most recent full year measurements were available the rate of movement doubled to 32 feet per annum. (Based on incomplete data for this year, researchers say they believe movement of the lobe has “slowed some.”)
The lobe was located 19 feet from the highway’s old section at the end of July. Dec. 15 saw the lobe close to 7 1/2 feet. This confirms the relentless marching lobes, and validates the concern that the Dalton or Trans-Alaska Pipeline may be engulfed by them.
Scientists have documented the lobe’s daily, incremental movement. The lobe moved at 0.04 inches per day in the early 2000s when it was first discovered. Daily monitoring of Debris Lobe A at the University of Alaska Fairbanks shows that the pace has increased up to one inch per day. A time-lapse collage spanning January to October 2021 shows how the lobe marches downhill towards the abandoned highway.
Daanen uses another metric to measure the movement of Debris Lobe A. It’s not all that scientific, though it is telling. It took him 30 minutes to walk from the Dalton Highway to the leading edge Debris Lobe A a decade ago. He can now walk the distance in less than a minute.
As obscure as these debris lobes might seem, they are an indicator of the growing range of climate change threats to Alaska’s environment. Climate change in Alaska has many visible consequences. According to Gabe Wolken, a geologist at the Alaska Department of Natural Resources, the lumbering masses represent the extremes that global warming has wrought.
“Debris lobe acceleration really underscores how climate change affects the various elements of the cryosphere,” he said.
Rerouting the Dalton
When state officials realized that the old section of the highway was in the bull’s eye of Lobe A, it became a race against time to develop a protection plan. Because of its role in transporting critical supplies to North Slope communities as well as oil field operations, the Dalton is also known as the Haul Road. It is also the lifeline of the pipeline, providing vital access for inspections, maintenance, or emergency response.
According to the Alaska Department of Transportation, approximately 200 vehicles per day travel the Dalton. About half of these are commercial trucks supporting oilfield work and native communities carrying approximately 2,500 tons of goods or supplies.
Transportation officials have come up with a range of solutions to protect the highway. To fast freeze the pile, liquid nitrogen could be injected into it.
The state eventually decided that realigning a 4,000-foot section was the best strategy. The new segment was completed in 2018 approximately 400 feet from the debris lobe and cost $2 million. The pipeline is located another 260ft away. These distances will save time, although there is much uncertainty as to how the continued warming will affect the acceleration of the lobes.
The old section of highway was left in place to bait the lobe. Engineers and researchers are eager to observe the collision. To document the slow death of the old road, engineers have placed seismic sensors, timelapse cameras and markers. Its death will allow for a better understanding of the destructive nature and lobes.
Once Debris Lobe B has conquered the abandoned section, Currey, Daanen, and others claim they hope to discover important clues on how to manage the other huge earthen slugs who have crept within a mile or less of the highway and pipeline.
“We think we can learn a lot from this and use that information to figure out how best to protect other sections in the path of these lobes,” Currey said.
Thawing Permafrost Unleashed
Scientists believe that the lobes were formed sometime in the past ice age, approximately 5,000 to 10,000 years ago. The retreating glaciers left bowls that held dirt, rocks, and other material. Permafrost is made from water and snowmelt that was froze.
The permafrost has held the lobes in their place for many years.
They were still solidly anchored when a U.S. Geological Survey geologist mapped the North Slope route for the pipeline. At the time, the lobes appeared to be inactive and unmoving. Certainly, they weren’t considered a threat to the pipeline that would open in 1977 and cover 800 miles from Prudhoe Bay in the north to Valdez in the south.
However, temperatures began to rise in Alaska.
The heating caused the permafrost to thaw. This set off a series of events that awakened frozen debris monsters, and sent them on a slow-moving collision course to the pipeline and highway.
Daanen, then an University of Alaska Fairbanks researcher at the time, and his coworkers first noticed something odd about the lobes around 2005. They noticed some trees were kind of cockeyed, so oddly rotated that they earned the nickname “drunken trees.” Initially they thought this was an indication of thawing permafrost. It was. It also signaled something larger, they discovered.
The scientists climbed onto the lobes to see giant spruce trees open and twisted. Some trees were upside-down, with the roots facing the heavens. They noticed huge cracks in their earth. These were sure signs that the thing they were standing on had movement, Daanen said.
The movement probably began with the melting permafrost. This allowed the lobes to loosen and allowed them begin their first, barely perceptible creep. It cracked open as the earth moved. Water from melting snow and increased rainfall caused by rising temperatures could seep into the lobes through these fissures. This increased the weight of lobes which, in turn, accelerated downward movement. That movement led to bigger cracks that allowed more moisture into the lobes—all the time the permafrost continued to thaw.
“With continued warming, it doesn’t look good,” Daanen said. “The conditions will add to the acceleration of the lobes.”
The 1960s saw the lobes frozen solid.
Trans-Alaska Pipeline developers began to plan the route that the 800-mile pipeline would take in the late 1960s and early 70s. The route had to be direct, cost effective to build and out of harm’s way.
Tom Hamilton, a newly-minted U.S. Geological Survey geologist and his colleagues had to map and identify natural hazards that could threaten the pipeline in Northern Alaska. Their work would be used as one metric to select the pipeline’s route—and identify any potential threats posed by nature that could lead to the destruction of the pipeline. Potential threats identified by the surveyors were earthquake faults, soft spots in ground caused by buried lake sediment, and landslide chutes.
The list didn’t include the debris lobes.
It’s not that the lobes went unnoticed. Hamilton and other geologists flew over them for a bird’s eye view, hiked to them for close up inspection and mapped their locations. Hamilton stated that there was nothing to alarm.
The debris lobes, which are now moving towards the pipeline and highway, were then fixed in place like concrete fence posts.
“They were stable and didn’t appear to be going anywhere,” Hamilton said. “They seemed to be frozen in place. So, we figured there was no cause for alarm.”
Hamilton, 85, has been retired from USGS for 17 year and recalls standing at one of the debris lobes’ toes and thinking about how solid and firmly they were.
“It didn’t seem like they’d be moving anytime at all,” he said.
Hamilton is now able to reflect on how his assessment today of the debris lobes has changed, as Alaska’s temperatures are rising.
“They would have been considered a hazard back then if we’d have seen what we see today,” he said. “No doubt.”
Source: Inside Climate News