Sleeping giant: Inside the Mount Meager volcano

Something melted a hole through the glacier above the Mount Meager Volcano in 2016. A perilous expedition ventured deep inside the cave to find out, did the volcano wake up

  • Aug 25, 2023
  • 3,894 words
  • 16 minutes
Christian Stenner (in red) and Kathleen Graham exit the upper entrance to the cave below Mount Meager’s Job Glacier. On this descent, they discovered the volcano’s fumerole, from which they took samples. (Photo: Adam Walker)
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Christian Stenner walked across British Columbia’s Job Glacier and came to a hard stop. At his feet, the icy ground ended at a precipice. On the other side, he could see a cave.

Stenner was looking into a seven-metre-wide chasm. Across it, toxic steam gushed from a tunnel, obscuring what lay behind. The air reeked of rotten eggs — a warning sign of hydrogen sulfide gurgling up from somewhere inside. 

Over there, Stenner thought, is where I need to be.

He decided to swing himself across the pit by a rope anchored to the cave’s entrance. Stenner checked his rope and jumped as far as he could. He didn’t quite make it across, and as he swung back and forth like a pendulum over the pit, he pumped his legs to gather momentum. His breath echoed loudly through the respirator covering his face. Each inhale ate away at the supply of compressed air held in a tank on his back. 

Then, a crunch: his crampon stuck into the ice on the other side of the chasm. He pulled himself onto the ledge and into a space where no human had been before.

Stenner was inside a cave squished between the glacier atop the Mount Meager massif and the volcano that hides beneath.

He was in search of a fumarole, the vent that was spewing deadly gas from the volcano. But all Stenner could see was steam. He checked his watch; he was out of time. He had to turn back or he’d run out of air.

With that, the hunt to solve the mystery of Mount Meager took another twist. Stenner had no concrete answers for the scientists who stood on the glacier above him, waiting to find out if Canada’s most dangerous volcano was waking up. 

Members of the 2022 Mount Meager expedition near the upper entrance to the cave. (Photo: Glyn-Williams-Jones)
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Mount Meager (Qwe̓ lqwe̓ lústen) is one of the northernmost volcanoes of the Cascade Arc, a series of volcanoes that rise out of Northern California, Washington and Oregon, and up into British Columbia. Shrouded by its glacier, Meager’s potential for ferocity gets overlooked. But it is one of two Canadian volcanoes that meet the criteria for a “very high” threat according to Natural Resources Canada; Mount Garibaldi (Ch’kay-Nch’kay), about 94 kilometres south, is the other. This ranking does not reflect the probability of an eruption, however — that precise calculation is unknown. In lieu of a good prediction tool, a high threat level is given to a volcano deemed likely to harm people or damage property, based on its geology and the exposure risk. As one volcanologist put it, Mount Meager has location, location, location. Its peaks look out over the town of Pemberton and the lush farmland of the Sea to Sky corridor with its more than 33,000 permanent residents. Just over 150 kilometres south lies Vancouver. 

Graham and Stenner (right) strap on respirators as they prepare to enter the cave’s upper entrance. (Photo: Adam Walker)
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Qwe̓ lqwe̓ lústentranslatesto“cooked face place” or “really hot face” in Ucwalmícwts, the language of the Líl̓wat First Nation. This name dovetails with the story of Mount Meager that scientists have put together. It goes like this: the volcano last erupted about 2,400 years ago, almost yesterday in geological terms. A viscous lava, heated to 800 to 900 degrees Celsius, began to push out of the side of Plinth Peak, the tallest peak in the massif. Without room to move, the growing mass exploded, launching into the sky a glowing cloud of ash, gas and car-sized rock fragments that ripped down the upper Lillooet River Valley at speeds of hundreds of kilometres per hour. The mass couldn’t find enough space to spread out and cool. Instead, the material began to weld itself together, solidifying into a giant dam across the Lillooet River measuring a whopping 110 metres high and more than three kilometres long. Over the next month or maybe two, water pressure built up in the lake that had formed behind the rock wall. According to modelling done by the lab run by University of British Columbia volcanologist Kelly Russell, water burst over the dam and began to slice downwards into the volcanic rock. The force unzipped the land to form a canyon that opened into a waterfall and series of basins. What’s most shocking was the violent speed: water split through 2.5 kilometres of rock in about eight hours. 

“This kind of biblical level flooding and unzipping of solid rock, we just don’t think about in modern geologic timescales,” says Glyn Williams-Jones, a professor in the department of earth sciences and co-director of the Centre for Natural Hazards Research at Simon Fraser University. “We think everything’s slow and steady. And this was almost back into the old days of a catastrophic event.”  

Today, the product of this rupture is a bucolic Instagram hot spot. The resultant Keyhole Falls (Múml̓ eq) and Keyhole Hot Springs are now among the area’s popular hikes, as well as being an important spiritual, cultural and food gathering area for Lílw̓ at Nation. It’s easy to forget that the majestic peaks of the massif, which reach an elevation of 2,680 metres at its highest point, are capable of extreme destruction. But they could, in a matter of hours, dramatically rearrange the verdant pastureland of the valley below.

The danger became very real one weekend in August 2010: around 3 a.m. on a Friday morning, unstable rock layers of the Mount Meager massif gave way, and 53 million cubic metres of rocks, snow and mud came crashing down in Canada’s largest landslide, blocking the Lillooet River. About 4,000 residents of the Lillooet River Valley were told to prepare to evacuate as water pressure built up behind the dam, which appeared ready to burst at any moment. That same weekend, however, Meager Creek mercifully cut a new channel through the debris and eased the buildup. It was a shocking reminder that the grand mountain is highly unpredictable. 

Brilliant blue scalloped ice walls form as warm air from below moves over the surface of the glacial ice. (Photo: Adam Walker)
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Six years later, a helicopter pilot, who’d studied geology at the University of Victoria as an undergraduate student, was flying a group of biologists into the area when he noticed something strange — a large hole, like a gaping mouth, perforated the Job Glacier. Steam was rising from it. The pilot took photos and sent them to his former professor, and eventually they found their way to Williams-Jones.

The question immediately on everyone’s mind was the same: just how active is Mount Meager? Forecasting volcanoes is a tricky practice, not unlike forecasting the weather. Consider a rainstorm. Many variables in the atmosphere influence whether a city will be pounded by rain. The signs may be crystal-clear 20 minutes or even two days beforehand, but not so one week or six months out. The same is true of volcanoes, but with an extra challenge: the variables are deep underground, hidden from analysis. At Mount Meager, there’s also a glacier to contend with. 

To find answers, volcanologists watch trends over time. They pay attention to subtle changes in temperature or gases that are percolating to the surface. They are on alert for tiny earthquakes and the lifting of the ground around the volcano, indicating magma, other fluids and gasses are moving underneath. At Meager, however, the glacier and the toxic gasses emanating from the massif make it incredibly difficult for scientists to access the volcano to test temperature and gas. Adding to the challenge, Canada has not historically monitored for changes at volcanoes. It’s expensive to carry out regular monitoring and there are other more pressing concerns for governments and academia given that an eruption seems unlikely and remote. A volcano? Erupting? Near an urban area? 

But it is perfectly plausible. Just ask the people in Washington State who live near Mount St. Helens, a volcano also in the Cascade Arc that infamously erupted on May 18, 1980. Fifty-seven people were killed; 200 homes and nearly 300 kilometres of highway were destroyed. Ever since, the United States Geological Survey has maintained a rigorous monitoring program. But in Canada, the country’s volcanic eruptions are beyond living memory; most volcanoes are in remote areas and covered by glaciers. Monitoring them is an expensive proposition, to the frustration of people who spend their lives studying them. “There are other priorities. There are the wildfires that we’re seeing in Alberta right now. 

There are mass floods, atmospheric rivers and landslides. So, volcanoes are low on the priority list,” says Williams-Jones.

This kind of biblical level flooding and unzipping of solid rock,
we just don’t think about in modern geologic timescales.

But the appearance of a steamy cavern in the Job Glacier sparked action. Natural Resources Canada, citizen scientists and private industry joined forces to launch an investigation into Mount Meager. On one of several reconnaissance trips, Williams-Jones stood on the glacier, lowered a gas sensor into a crevasse and measured hydrogen sulfide levels of 280 parts of gas per million. Anything more than 100 ppm is considered immediately dangerous to life and health. Later, Williams-Jones saw four dead finches lying on the ice by the vent. After consulting with a biologist colleague, Williams-Jones came to the conclusion that the birds flew close to the outlet in search of warmth in the spring and were overcome by the fumes from below — a literal case of the canary in the coal mine. Their deaths added to the evidence that the vent was belching lethal levels of gas. 

Given the risk, no one would be getting anywhere close to that fumarole under the ice. Williams- Jones and his colleagues stayed a safe away from the cave entrance and watched carefully for crevasses on the glacier — any hole could be a pocket full of deadly hydrogen sulfide, which is invisible and heavier than air so it settles into low-lying areas. For now, whatever clues Mount Meager held hidden under the glacier were out of reach.

A steady plume of gas and steam billows from the upper entrance to the cave. (Photo: Glyn Williams-Jones)
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Christian Stenner, a 43-year-old security expert in the energy industry, and Kathleen Graham, a 40-year-old accountant, had started exploring caves in Alberta in the mid-2000s. They eventually met through the Alberta Speleological Society at a caving event around 2009 near their hometown of Calgary. Over the next five years, the pair began to shift into uncommon territory for cavers — the mysterious spaces between glaciers and volcanoes. Glaciovolcanic caves form when heat and gas from a volcano warp the ice of the glacier above, creating tunnels that are continuously morphing. Inside, these caves are “like a cathedral of ice,” says Stenner. The beauty is otherworldly: white and blue rooms carved into ice, with curved walls that look like they are made of hundreds of giant white seashells. 

Only a handful of cavers worldwide explore glaciovolcanic caves. The risks are enormous: rocks and ice fall frequently from the ceiling as steam gnaws at the underside of the glacier. There can be dangerously high levels of hydrogen sulfide, sulphur dioxide and other gases. A few cavers, however, accept the risk, drawn by the beauty and the opportunity to work as citizen scientists, gathering on-the-ground details to feed back to the scientific community. “It’s more than just personal,” says Stenner.

Map: Chris Brackley/Can Geo
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Beginning in 2014, Stenner and Graham joined an expedition to explore Mount Rainier and map its cave system. Over three years, Stenner (Graham left after the first year) surveyed 3.5 kilometres of caves ringing its eastern crater, the longest known glaciovolcanic cave system in the world.

In 2018, Stenner gave a talk at Calgary’s Mount Royal University about the expedition. As chance would have it, in the audience that night was the son of a scientist at Natural Resources Canada, who immediately saw a potential solution to the problem plaguing the Mount Meager investigations. The son connected Stenner to his father, who connected him to Williams-Jones. Within a few weeks, plans for a Meager expedition were underway.

Williams-Jones wanted three measurements: the temperature, gas composition and gas concentration at the fumarole. As a volcano moves closer to eruption, its magmatic system heats up and the gas composition evolves, becoming richer in sulphur dioxide. “If we see significant changes in [gas composition] over time, that can give us insight that maybe there’s new magma getting closer to the surface,” says Williams-Jones.

The beauty is almost otherworldly: white and blue rooms carved into ice, with curved walls that look like they are made of hundreds of giant white seashells

In 2019, Stenner, Graham, Williams-Jones and a support team visited Mount Meager. The cavers took the same air-supply system they’d used at Mount Rainier, which would give them 45 minutes to one hour of safe air inside the volcano. The window was tight; they’d have just enough time to measure the temperature if the fumarole was located directly below the hole in the glacier and pumping gases straight up like a chimney.

Stenner went in first. Graham waited at the cave’s entrance. That’s when Stenner discovered the fumarole was off somewhere down a maze inside the cave system. The 2019 expedition came to a halt without any real answers. 

Over the next two years, another large hole formed in the glacier, this one about 100 metres from the first. Three tiny cracks appeared nearby, which had the effect of skylights into the cavern below.

Something was changing.

Team members prepare to enter the cave on day two. This was Stenner’s and Graham’s first attempt to bypass the two vertical sections of the upper entrance to the cave. (Photo: Adam Walker)
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Graham and Stenner started planning their return. First, they needed to figure out a life support system that would allow them to breathe safely for longer while they worked in deadly levels of toxic gas. Mount Meager was filled with more treacherous air than any other glaciovolcanic cave they knew of; no breathing system that the cavers had used would protect them from its stew of toxic gases for long enough.

One company offered a life support system that that could be used over several hours, but it needed to be recertified after every use and was prohibitively expensive — rendering it impractical for a team on a multi-day expedition. A company that makes military-grade equipment suggested Shield, a brand of self-contained breathing apparatus with an air-purifying mode that filters dangerous gases out of the air as the user inhales. But this, too, had a catch: the filters are American military technology and restricted for export. On the internet, Stenner found similar filters at a store that sold military and tactical survival supplies in Red Deer, an hour and a half up the highway from his home in Calgary. Stenner bought its entire stock of filters. “They would filter chemical weapons, but they would also filter hydrogen sulphide and sulphur dioxide,” he says. No one had used the SHIELD system inside a cave before, but Graham and Stenner calculated that this system could do the job. 

Inside the cave, Stenner wears a gas monitor on his arm. (Photo: Adam Walker)
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In September 2022, a 14-person team of cavers, safety support members and scientists arrived at a dorm at Pemberton Meadows, a short drive and a helicopter ride away from Mount Meager. The group included Jill Mikucki, a microbiologist from the University of Tennessee and a world expert in polar microbial ecology. She’d spent years focused on Antarctica, studying microlife that exists in difficult-to-reach water beneath glaciers — the best place on Earth to prepare for, one day, studying life in alien ocean worlds. As we rapidly lose glaciers to climate change here on Earth, Mikucki is in a race to document the diversity of life and the genome of any microbes in these environments. “This is where we discover antibiotics and anti-cancers and some of these novel natural products that can be very useful to humans,” she says. 

Two NASA engineers also joined the crew, carrying with them the head of a robotic ice snake called EELS, short for Exobiology Extant Life Surveyor, to help train its artificial intelligence system. The space agency’s Jet Propulsion Laboratory developed EELS for a possible space mission to Enceladus, one of the 146 moons orbiting Saturn and widely considered one of the places other than Earth most likely to contain life. Enceladus is an ocean world, measuring about four per cent of the Earth’s size. It’s encased in a crust of ice, except for the geysers on its surface that spew giant plumes of water, ice particles and other chemicals. EELS was being trained on Meager as a vehicle to capture information about the surface of Enceladus and its geysers — and, perhaps, find answers to the question of whether there are signs of life in its waters.

The team buzzed with excitement as they set out in helicopters from base camp to the glacier. They were a mix of elite scientists and experienced cavers from different disciplines. For many, this would be the first fieldwork they’d done since the pandemic. Everyone was “sparking off each other,” says Williams-Jones. He called the expedition “a serendipitous cross-pollination of information and ideas,” with people trading questions and answers. On one of the helicopters, passengers noted they’d filled the
bird entirely with women scientists, including Graham. They celebrated by singing an acapella version of Madonna’s “Like a Virgin.”


After landing at the glacier, Graham went first into the cave, this time rappelling down into a large cloud of steam, where she could see the ground and a pit that was receiving water. At the base of the crevasse, she saw a long wall of ice that she’d have to traverse. It would be too costly in time. She returned to the top and the team decided to try the new hole.

From inside the second entrance, Graham and Stenner walked 60 metres across an ice floor and set up the rigging to rappel deeper into the cave system.

On the second day, they did two short rappels and found themselves on a hot, rocky floor. The pair stopped frequently to scoop sediment samples into little bags that had been prepared by Mikucki’s team. A vaulted ceiling of ice hung 20 metres above their heads. On the ground, patches of bright yellow needles of crystal popped through the haze, indicating the presence of sulphur dioxide. This gas comes off the magma in an active or potentially active volcano — not one that is extinct. Gases released at the fumarole work their way up through a complicated network to get to the surface, a process that changes their chemistry into hydrogen sulfide, exactly what the scientists could smell at the glacier.

Two team members traverse Mount Meager’s complex glacier terrain above the steamy lower cave entrance. The team later discovered an upper entrance with easier and safer access to the cave system. (Photo: Adam Walker)
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It was a sign that the cavers were near a fumarole. Graham collected samples, bagging and labelling them. “I was pretty laser focused. This is our job, and we don’t have that much time,” she says. Meanwhile, Stenner wandered nearby, taking temperature readings. So far, 90 degrees was the hottest they’d recorded. He stepped up on a mound of volcanic rocks, and his gas monitor went off, indicating the toxic gas level was over the measurable limit. He switched to his purified air supply, then turned
back to return to Graham, when he was blasted by a column of steam. He could barely see his hands. His crampons were poking into rock, which made him unstable. If he tripped and got injured, it could be impossible to get him out. He was sweating in the heat, and the steam had soaked through his jacket. He took a deep breath and started to move forward in baby steps. One foot, carefully; then the other. He slowly made his way off the rocks and out of the heavy steam.

When he returned to Graham, she chastised him for venturing off on his own, reminding him it was dangerous. “Yeah, I learned,” he told her. He held a bag open so she could deposit sediment into it, and he felt the heat burning through his latex gloves as rocks landed in the bag.

The pair continued down a slope and into a hallway with a rocky floor. They were now on a lower level of the cave, like a long narrow basement. They could hear ice and rock falling — the sounds of the cave disintegrating around them. With steam obscuring their vision, they couldn’t see dangers. Sometimes, they’d catch a glimpse of seracs, massive blocks of unstable glacial ice, hanging from the ceiling. “Walking by those was like, eww, that’s unnerving,” says Graham. “You just look above you and walk fast.” In all, they explored through approximately 258 metres of cave. They passed a second fumarole field, a stream and a pool of water, before arriving at the first entrance. The team was unable to map the inside of the cave in detail (the lasers that scientists typically use to survey beneath glaciers didn’t work in the heavy haze of Mount Meager’s recesses), but they did manage to hand sketch an outline of a lopsided horseshoe of a cave system with water and fields of rock. 

Their work has confirmed that Mount Meager is not just an extinct, cold mountain. This is something that is active

Over three days, the cavers took 17 samples. On the first night, at base camp, Mikucki tested a sample and found adenosine triphosphate, the molecule used by all living cells as fuel. Indeed, life exists at Mount Meager. Since then, Mikucki has been testing the samples to see if the microlife is unique to Mount Meager and to learn how it survives in such austere conditions. She is hopeful these microorganisms are chemoautotrophs (which produce their own energy by oxidizing inorganic molecules, such as sulphur), making them a useful analog for microlife outside of Earth. Her team has now cultivated microbes from the Mount Meager samples and is able to grow them on petri dishes, to then extract DNA and start to sequence the microorganisms’ genomes.

Meanwhile, NASA formally unveiled EELS in May 2023, saying the targeted expeditions carried out by its engineers at Mount Meager with the robotic snake had allowed the AI system to gather enough data to render EELS now capable of picking a safe course through a wide variety of terrain on Earth, the Moon and far beyond, including the labyrinthine spaces within glaciers.

And in the hunt to figure out the mystery of the Mount Meager volcano, scientists now have a “fingerprint” — a measurement of a moment in time, says Williams-Jones, one that will help build the baseline data for Mount Meager’s activity. Their work has confirmed that Mount Meager is “not just an extinct, cold mountain. This is something that is active,” he says. But it is not immediately about to erupt. The hottest temperature reading from within was 90.5 degrees.

Still, scientists and cavers will keep going back to monitor changes over time, he says. The federal government has also started a satellite monitoring program of Canadian volcanoes, which will help identify changes on the surface.

Right now, birds are flying around the Mount Meager massif. A rock is sliding down one of its slopes. Water pours over Keyhole Falls. Somewhere under the glacier, a vent is burping hydrogen sulphide into the air. Mount Meager’s future is a mystery. But we know this: the volcano is neither extinct, nor erupting — it’s evolving and, one day, this scene may look very different.

This expedition was funded in part by National Geographic and Canadian Geographic through a Trebek Initiative Grant. trebekinitiative.com


This story is from the September/October 2023 Issue

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