In the almost 60 years since a ski resort began operating on Whistler Mountain, the Sea to Sky corridor has boomed.
A gravel road turned into a multi-lane highway, while the number of people who called Whistler home grew from under 1,000 when it was incorporated as a resort municipality in 1975 to almost 14,000 in 2021, according to Statistics Canada’s most recent census. That’s before taking into account the corresponding population spikes in Pemberton and Squamish.
Despite those changes, the region has, geographically, stayed fairly consistent since settlers first showed up—including the Garibaldi Volcanic Belt (GVB), the northern arm of the Cascade Volcanic Arc that includes massifs such as Mount Baker and Mount St. Helens. It’s well documented that much of the rocky terrain across the Sea to Sky can be attributed to a long period of extensive volcanic activity spanning millions of years, culminating with an explosive eruption of Mount Meager about 2,350 years ago.
What’s less clear is how significant a hazard volcanoes like Mount Cayley and Mount Garibaldi in Whistler, and Meager near Pemberton, pose to the corridor and its growing population today. Are those volcanoes at risk of erupting? What would happen if they did?
It’s what academics like Conner Morison are working to help figure out.
The University of Edinburgh PhD student authored Mount Garibaldi: hazard potential from a long-dormant volcanic system in the Pacific Northwest, alongside volcanologist Catherine Hickson, based on research Morison conducted as an undergraduate at St. Andrew’s University. The research paper was published in the Canadian Journal of Earth Sciences last month.
The paper compiles existing research about the Mount Garibaldi Volcanic System, but argues more monitoring is needed to paint an accurate picture of “the hazards posed by long-dormant but potentially active volcanoes,” such as Garibaldi, the paper stated. It’s “important so that communities can be more prepared for unexpected eruptions,” the authors added.
“Nothing has changed—I don’t want to spark undue alarm,” Morison told Pique. “But this is bringing Garibaldi a bit more up into line with other volcanoes that are dormant, but potentially active.”
He added, “There’s no evidence to suggest that it will never erupt again.”
Morison said researchers haven’t been able to determine whether a magma chamber still exists underneath Garibaldi, but can tell the volcano erupted roughly 10,000 years ago, towards the end of the Ice Age. “But that’s not to say we’ve identified the most recent eruption,” he said. “That’s just the deposit that has been radiocarbon-dated—there may well be something that has been missed, but further research on Garibaldi would perhaps find that.”
Evidence of both lava flows and hot, ground-hugging ash and debris flows called pyroclastic density currents from that event was found reaching all the way to Squamish, highlighting potential risks if a similar event was to occur today. In the event of an eruption, Whistler and its infrastructure could be severely impacted by volcanic ash and tephra, or rock fragments, while the hot lava could even spark forest fires, depending on the time of year. Still, those previous eruptions occurred in an undeveloped landscape that was still covered by retreating ice, said Morison, making likely impacts of any future eruptions difficult to predict.
Gaps of thousands of years between eruptions is common, particularly in the Cascades. “We need to know more about how often Garibaldi has erupted in the past—and why is it quiet now?” Morison added.
Here’s what researchers have been up to at Meager
Those occurrences have been better documented at Mount Meager, another GVB massif located about 60 kilometres northwest of Pemberton. The volcano was the site of Canada’s largest landslide in 2010 and has been studied for its geothermal energy potential since the ’80s, but drew renewed interest after a helicopter pilot, by chance, spotted gas seeping out of fumeroles, or vents, on Meager in 2016.
Aside from its most recent eruption about 2,350 years ago, researchers recently identified another eruption that they estimated took place approximately 24,000 years ago, said Glyn Williams-Jones, a volcanologist and chair of the Earth Sciences department at Simon Fraser University (SFU).
That data “is important because it allows us to start to try to get a handle on how the volcano behaves,” he explained.
Last summer, Williams-Jones joined researchers from the University of British Columbia, SFU, the University of Tennessee Knoxville and NASA’s Jet Propulsion Laboratory, plus “a whole army of expert cave search-and-rescue professionals,” for several days in Meager’s glacier caves.
Williams-Jones said researchers located and measured a few of those fumeroles, and determined sulfur dioxide was present within the ice caves. That “clearly supports the idea that this volcano’s obviously not extinct,” he said.
Studying those fumeroles is just one of several multidisciplinary research methods crews are currently using to learn more about Meager. Teams are turning to both computer models and cameras to monitor how Meager’s ice caves and slopes are changing alongside the climate, while Williams-Jones and his fellow researchers are currently working with provincial and federal agencies, like Natural Resources Canada, to develop a “semi-automated satellite monitoring program” using Canada’s RADARSAT satellite system to measure how the terrain is changing within the GVB. That monitoring is already underway at Garibaldi. Meanwhile, Meager Creek Development Corp., the group working to harness geothermal energy from the site, also shares data with researchers from the seismometer and other monitoring tools it operates onsite.
“The things that we’re trying to understand are: are the movements on the mountain due to just the instability of the mountain, because of things like changing climate, or are there signals of renewed volcanic activity?” he explained. “We don’t see that at the moment, thankfully, but at the same time, that’s where we’re trying to expand the ground-based monitoring.”
One way to accomplish that would be a bigger network of inexpensive seismometer models, or through good old fashioned firsthand accounts from those recreating throughout the GVB’s peaks. In other words, citizen science.
Williams-Jones’ ultimate goal would be to develop an app or portal where those observations can be submitted.
“What I’m always looking for is people who’ve seen something different,” he explained.
“If people who are in the area, who were out there skiing or hunting, or whatever and they see something odd, whip out the phone, take a photo … ‘I smelled rotten eggs here, and I saw hot ground here that I’ve never seen before.’ That kind of information is really important, because we’ve got this big, broad country that is often inaccessible or challenging to access,” Williams-Jones added, “but we have people who are getting out into the backcountry.”
From an academic perspective, “we still know relatively very little about these mountains that are in our backyard,” he said. “That’s where a lot needs to be done."
