Fractured Forest

Alberta's Seismic lines dilemma

By Liam Harrap

A yellow ski-doo pulls two sleds across an icy outflow. The machine loses grip and its track begins to spin aimlessly. Lyle Dupperon stands and rocks the machine from side to side. Left, right, left, right. Eventually the belt beneath catches, and with a puff of exhaust Dupperon zooms forward.

Dupperon is a 51-year-old fur trapper, and although the trapping season just ended, he’s bringing supplies to his cabin for a 10-day bison hunt in the Caribou Mountains of northern Alberta.

As the soft mid-February light fades to yellow, pink and red, the wind blows swirls of dancing snow across the path. The trail is mostly straight, an endless line through thick and entangled forest. We’re on a seismic line, speeding along at 40 km an hour. If it weren’t for seismic lines, it could take days to reach his cabin. Instead it takes a few hours.


To find petroleum, oil companies build seismic lines. They clear trees and vegetation so that vehicles can drive down the lines and put explosives in the ground. The explosives are detonated and the frequencies measured to determine if oil or gas is below. The size and length of the lines vary: some are 10 metres wide, others only two. Most stretch for kilometres, going far beyond the horizon, even when viewed from an airplane.

A study by the National Research Council of Canada suggests Alberta could have more than 1.8 million km of seismic lines, which is the equivalent of twice the distance from earth to the moon and back.

When the lines were built, they were never understood to be permanent; they were left to revert naturally back to native forest. But many remain barren, even 50 years on. And while drilling and mining for oil extraction requires reclamation by law, no such legislation exists for seismic lines.

The lines disrupt mammals, birds and insects, as well as affect permafrost and carbon storage. The effects of seismic lines also spill over into the adjacent forest by changing plant and tree composition. Indigenous peoples of northern Alberta say the woods are emptying out and that seismic lines are largely to blame. A University of Alberta study found that seismic lines are particularly disruptive to wolves and caribou. The issue of wolves travelling the lines to more easily catch caribou has brought seismic line reclamation into the spotlight. The provincial government estimates that only 2,000 caribou are left in the province, though it admits the exact number is unknown.

In 2017 Alberta’s NDP government released a draft caribou range plan to help caribou herds recover and become self-sustaining. The documents include plans to restore and reclaim seismic lines across the province. This was the first major government strategy attempting to address the problem of seismic lines. Due to opposition from the public and industry, who feared the cost of mandated reclamation, the draft plan was suspended in 2018. In 2019 the UCP government announced it had established three task forces across the province to revisit the 2017 caribou draft plan; they aim to release their recommendations this year.


We get to Dupperon’s cabin in darkness. One time, he arrived and found the interior in tatters. A fellow snowmobiler hadn’t properly closed the door or set the electric fence. A black bear got inside, smashed it up and ate all the food.

“There’s all kind of beings that live in places like this,” muses Dupperon as he passes me a hot toddy of rum, coffee, syrup and creamer. He switches on the satellite radio and we listen to “If Drinkin’ Don’t Kill Me (Her Memory Will),” by George Jones.


The oil and gas industry has built seismic lines since the 1940s. In the early days, the lines were wide, straight and spaced at distances of 300–500 metres. Bulldozers were used to clear the land and remove topsoil. Little consideration was given to restoration or replanting. These seismic lines were called 2D, or legacy lines, and could be up to 10 metres wide.

Today, seismic lines can be as narrow as 1.75 metres and are built in a grid pattern, sometimes only 50 metres apart. While these new grid-pattern seismic lines are narrower, they are also more frequent. For example, instead of 1 km2 of forest having one seismic line, as with the old legacy lines, with the new model it can have 20. Each line provides data on the fossil fuel deposits below, such as the exact position and depth. The greater the number of lines, the more exact and comprehensive the data. These new lines are called 3D, or “low impact” lines.

Jesse Tigner, a senior ecologist at Explor, a global seismic exploration company, says the only reason seismic lines exist is to move equipment. “It’s a huge cost. What we really want to know is what’s going on under the ground.” Tigner says that in rough, rugged and remote terrain it can cost up to $100,000 per km to cut a seismic line. On flat, easy-to-access terrain, only $3,000 per km.

Right now companies needn’t factor in reclamation expenses. While voluntarily replanting and restoring seismic lines to natural forest is still in experimental stages, Michael Cody, a biologist at Cenovus, pegs the average cost of restoration at $10,000 per km.

Cenovus has a restoration pilot project near Cold Lake. The company is spending $32-million over 10 years to treat an area five times the size of Calgary. Treatments include planting roughly one million trees, mounding dirt in swampy areas to make tree growth easier, and creating wood piles and leaning tree stems to block the lines (making them harder to travel for humans and animals alike).

So far Cenovus has replanted more than 700 km of lines in caribou range. They plan to restore 3,900 km, with the intention of helping caribou populations rebound. Although energy companies aren’t required by law to do this, Cody says “environmental integrity is important to our company.” And Cenovus has had some positive results from restoring seismic lines. Some trees the company planted in 2008 are now more than 4.5 m in height, which is far taller than most trees on lines that were cut in the same year but not replanted.


The sky is cloudless. We stand on top of a bluff overlooking Dupperon’s trapline. The Caribou Mountains gently rise in the distance behind a sea of spruce and frozen lakes.

Faint lines ripple across the expanse, but they’re hard to see. Dupperon used to travel those seismic lines a few years back, but now it’s too difficult. The forest has taken them back, he says. We jump back onto our ski-doos and speed off. Branches grab our jackets as we whiz past, as if they’re slowly reclaiming this line as well.

Seismic lines are disruptive to wildlife, particularly wolves and caribou. Wolves travel the lines to more easily catch caribou.

In truth, replanting seismic lines is tricky and not well understood. “It’s an open question,” says Scott Nielsen, professor of conservation biology at the University of Alberta. Nielsen’s lab specializes on research pertaining to seismic lines. “There’s been a lot of restoration, for sure. But to be honest, just establishing trees in the ground isn’t restoration.”

It all depends on how you define restoration. “That’s the billion-dollar question,” says Nielsen. “What is success, and what would it look like?”

For Alberta’s forestry industry, once the average tree is 2–3 m tall, the landscape has been officially restored. After an area has been logged, it can’t be relogged for 10–20 years.

Nielsen, however, says that while clumps of 3-metre trees might stop wolves from travelling down seismic lines, different species may not view the same forest as recovered. “An ovenbird might perceive 2–3-metre height on a seismic line as a massive, open corridor in some habitat. A fisher [a small member of the weasel family] might perceive it completely differently, and a rare plant completely differently. Every species has its own niche and its own response,” he says.

A 2005 study by the University of Alberta suggested ovenbirds use seismic lines as territory boundaries. The birds perceive the lines as forest “gaps.” In some cases, due to the frequency of lines, the birds have smaller territories.

Since the lines have less leaf litter, they also have fewer arthropods. But a recent study by Federico Riva found that butterflies have a higher abundance and diversity on legacy lines than in nearby forest. The diversity and abundance of butterflies decrease as line width shrinks. The lines become “highways,” allowing more species to travel and mix.

Regardless, getting trees to grow on seismic lines is tricky. Restoration is proving especially difficult in two types of boreal ecosystems: dry, sandy, pine forests; and peatlands.

Nielsen says little research exists on why restoration in pine forests is difficult, but studies have shown those lines to be revived after a forest fire. “For the most part you need fire in those systems to open the cones.”

Peatlands are low-lying areas with an accumulation of decaying vegetation. They are notoriously wet, and when seismic lines are cut there, the vegetation becomes flattened and is often pushed below the water table, making it difficult to replant trees.

As fate would have it, peatlands are favoured by caribou. Wolves have tended to avoid peatlands since they have fewer moose and deer, which have traditionally been wolves’ main prey. By cutting seismic lines through peatlands, it’s easier to add caribou to the menu.

According to Alberta government data, more than 200,000 km of seismic lines run throughout the province’s peatlands.


A report by the Canadian government indicates environmental changes go beyond the lines and into adjacent forests. Since seismic lines provide a break in tree canopies, more light reaches the forest floor. Thus trees can ironically grow faster at the edges of seismic lines. With an increase in tree growth, the competitive balance among species can shift, resulting in fewer shrubs, flowering plants and mosses.

There is also more wind on seismic lines, sometimes up to seven times more, compared to adjacent forest. This can increase tree mortality. More deadwood along the edge leads to more fungi and lichens. More wind also disperses seeds faster and farther, which helps invasive species such as bluejoint reedgrass, which can smother conifer saplings.

Given all of these effects, “seismic lines can have an environmental impact that far exceeds any other human disturbance in northern Alberta,” says Nielsen.

Seismic lines are also associated with permafrost thaw. In areas of northern Alberta, a layer of soil is frozen year-round. This permanently frozen layer is sensitive to human disturbances such as soil compaction and removal of vegetation. On seismic lines, the frozen layer can melt, resulting in moister soil, which affects carbon storage. Because of slow decomposition rates, northern peatlands have long been a carbon sink (they store roughly one-third of the planet’s soil carbon, more than all of the world’s forests combined). In some places, however, they are becoming a carbon source as melting permafrost releases greenhouse gases, contributing to climate change.

Studies indicate that twice as much carbon dioxide is stored in permafrost as in the atmosphere, and that seismic lines increase methane emissions in Alberta by 4,400–5,100 metric tons annually. This is the CO2 equivalent of more than 27,000 cars.


Yellow ice covers the creek and we slow to a crawl. Dupperon’s ski-doo starts to twirl, the belt beneath failing to catch snow. His machine does a slow waltz across the ice, straightening in the fresh powder.

“Before seismic, trappers used creeks. And lots died. You fall through the ice, you break through overflows. It’s extremely dangerous,” says Dupperon with a toothless shrug. He lost all his teeth when a bull stepped on his face.

“I’m on borrowed time. I should have died years ago.” Once, his machine fell through ice and he was up to his chest in water. When Dupperon eventually got the ski-doo free, he managed to get back to his cabin quickly, using seismic lines. Without these straightaways for his speedy getaway, he says, he could have frozen to death.


In a house on a nameless gravel street in Fort McKay, Mary Powder, 77, prepares ribs. An award for Alberta’s Best Trapper, 2003, adorns the wall. Fish swim in a tank, and her husband, Zachary, 89, watches the news.

Zachary has been trapping north of Fort McMurray for more than 50 years. The Powders are part of the Fort McKay First Nation. When oil companies began building seismic lines in the region, everything changed.

“When they open a line, animal goes away,” Zachary says. “That’s what happens. All over traplines. Not only me. When they make a noise there, animal goes away. Everything changed.” Zachary is almost deaf, so Mary shouts my questions to her husband. She tells me that after I leave, he won’t remember I was here.

For the Powders, trapping was essential. Not only was it an important part of their culture, it put food on the table. The Powders wouldn’t agree with Lyle Dupperon. For them, seismic lines have destroyed everything.

“It’s how we brought up all our children,” says Mary. “We get money from the fur. We trap. Nobody scared away the animals before. Now, all the trees are taken down. They won’t grow. Damage to everything.”

When I ask if seismic lines should be replanted, Mary interrupts. “Never mind if they replant! They’re not our god. God grows everything. How many years will it take before something comes up? Because they killed all the roots. How many years before something comes up again?”

For the Powders, the damage is done. Nature is the best replanter and restorer of the land. It should be left to do what it does best—grow. Even if it takes a lifetime.

As I leave in the fading twilight, I notice an old pickup truck in the driveway. There’s a sign attached to the back window:

To love a person is to see all of their magic.

And to remind them of it when they have forgotten.

Their small house is surrounded by a fence decorated with flowers and butterflies. All is quiet. Yet the air is sweet and sickly from nearby mined bitumen. The smell cloaks the Powders’ home.


PinPoint ends the seismic line as we know it,” says Allan Chatenay, president of Explor. “It’s pretty groundbreaking.” The company pioneered the new technology, which uses a low energy source to map the subsurface.

As Tigner, who also works for Explor, said, seismic lines exist solely to move machinery to gather seismic data. Chatenay says to gather PinPoint data, they “just walk through the forest,” following the path of least resistance, carrying hand-held devices and a backpack. They need no trucks or explosives; they cut down no trees.

“We can acquire data without any measurable impact to the forest,” he says.

Chatenay says they’ll continue testing and hopefully roll out the technology commercially this year. But at the moment, using PinPoint is more expensive than building seismic lines. Chatenay says this is because more people and energy source points are required to create the data. For example, with 3D seismic lines, you might have 1,500 source points per km2. PinPoint has 10,000. But Chatenay argues the data Explor produces is of higher quality. “If you think about your TV screen, smaller pixels produce a much higher-resolution image. Each pixel doesn’t have to be as bright, but you have many, many more pixels, which makes it more expensive than a lower-resolution screen.” If the technology were cheaper, says Chatenay, “we’d have the market locked up.”

But even if new seismic lines can be eliminated, the problem of the old lines remains. Craig Dockrill, Alberta Environment and Parks’s director of land and environmental planning north, says the provincial government’s new task forces are “a little more holistic regarding the landscape and look at the various land uses that are important and interact with caribou recovery, which remains a priority for the government.”

He says the new draft will be “more forward looking.” Most concerning for the government, he says, are the old legacy lines, as they “are a large contributor of our concerns about caribou.”

If caribou were not declining, the U of A’s Nielsen says it’s possible seismic line reclamation wouldn’t even be discussed. “Caribou is the poster child that is driving a lot of this.”

Dockrill says government is mostly focusing on restoring lines within caribou habitat. According to the province’s figures, 250,000 km of legacy lines lie within such habitat, of which 150,000 km are of greatest concern.

If restoration costs roughly $10,000 per kilometre, 150,000 km could cost $1.5-billion. The government has yet to release a plan or a means to pay for restoration. Who will foot the bill—industry or citizens—remains an open question.

Dockrill says the government is less concerned with 3D lines, as they deem those to have less impact. However, since 3D lines are more frequent, the amount of area disturbed is greater. Nielsen says it’s possible 3D lines have a significant influence on the landscape.

Regardless, reclamation will need to consider the needs of more than just caribou: other wildlife, insects, flora, carbon storage, permafrost and Indigenous peoples’ use of the land. A forest that’s usually an entanglement of chaos now has seismic highways. It has been forever changed. Seismic lines were never meant to be permanent, but that’s what they are.


“There’s no straight lines in nature,” says Dupperon as we load the ski-doo onto his truck, his curly hair dancing as he talks. “There’s probably a reason for that.” We drive down a gravel road, heading back to his acreage.

When asked what he’d like the Alberta government to do about seismic lines and caribou, Dupperon says they should talk with the people who work on the land. “If something changes, we see it. Because this is our living room. If someone moves the couch, we’ll notice.”

Other than seismic lines, there’s little industrial development—oil drilling, mining, logging—in the Caribou Mountains, where Dupperon traps. It’s one of the least-disturbed caribou ranges in the province.

As we park, Dupperon says he’ll fight any changes the Alberta government proposes. For him, it’s important that seismic lines remain, and it wouldn’t hurt if they built more.

“The people being paid by the Alberta citizen have forgotten that they work for us,” he says. “They should work with us and not be dictating how things should go. We don’t work for them. They work for us. They need to remember that.”

As we leave the truck, there’s the sound of his galloping horses. A dog runs up, excited to see his master. Erin, Dupperon’s wife, has left us moose meat cabbage rolls in a casserole dish. For Dupperon, though, this will never truly be home. His home is in the bush, in a cabin without plumbing, with an outhouse for a toilet and seismic lines for a driveway.

Jasper-born Liam Harrap is a journalist and backcountry baking enthusiast. Send feedback to


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