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Dr. Alison Criscitiello's expedition to an ancient ice core offers clues on modern climate change

The expedition team climbs towards camp 1 on Mt. Logan in Kluane National Park and Reserve. Credit: Leo Hoorn/National Geographic
The expedition team climbs towards camp 1 on Mt. Logan in Kluane National Park and Reserve. Credit: Leo Hoorn/National Geographic

For a long time, glaciologists have suspected that Mount Logan’s summit plateau, the highest point in Canada, holds some of the region’s oldest ice.

Theoretically, they’ve known that buried deep in the Yukon’s Mount Logan was “potentially the oldest non-polar Arctic ice in the world,” said National Geographic Explorer, ice core scientist, and mountaineer Dr. Alison Criscitiello. “In the ice core community and climate community in general, it's been an important target,” she told FootPrint Coalition. “We’ve always known that there’s a much longer climate record sitting up there than has previously been retrieved.”

Now, after an expedition long in the making, Dr. Criscitiello and her team retrieved that record.

Back from the National Geographic and Rolex Perpetual Planet Mount Logan Expedition, Criscitiello now has an ancient ice core from one of the most coveted peaks in the world. How old is this core exactly? Likely, 30,000 years.

The information that such a​​n old core will be able to tell ice core scientists about climate change runs deep, from predicting temperature climbs to sea level rise to even wildfire frequency.

The depths Dr. Criscitiello and her team went to in order to retrieve the core are mountainous.

The expedition up what’s known as the “Roof of Canada” lasted six weeks and the ascent 10 days. It was a demanding trip. Criscitiello and her team of six high-alpine scientists were up against far below freezing temperatures, between 20 to -40 C, the extreme altitude of the mountain, and other intense weather conditions like strong winds, icefalls, and heavy snowfall. Not to mention, they were up against its monumental size, as the Mount Logan massif is a part of the most extensive non-polar icefield in the world.

Not all of the climbers made it to the top, due to the high altitude. Despite planning for this, Criscitiello ended up operating a 900-pound ice core drill on the summit plateau, working with a very “small, bare-bones team.”

The ice core drill in action at high camp, Mt. Logan. Kluane National Park and Reserve. Credit: Leo Hoorn/National Geographic
The ice core drill in action at high camp, Mt. Logan. Kluane National Park and Reserve. Credit: Leo Hoorn/National Geographic

Nevertheless, her team extracted a beautiful ice core. To Criscitiello, the depth of the core was the most surprising. Prior to drilling, she and the team narrowed the location down to the ideal site using data they had collected from radar surveys. A radar expert estimated that the spot was 260 meters, or 853 feet deep. The team’s extraction lasted 11 days, rotating three-hour shifts to drill into the mountain’s ice. Then they hit 260 meters. The drill kept going. 270, it drilled deeper.

280, it drilled deeper.

290, it drilled deeper.

300, it drilled deeper.

To their surprise, the depth was much deeper than anticipated, totaling 327 meters. With over 1000 feet in depth, Criscitiello and her team now have 35 cardboard boxes filled with ancient ice sitting in the freezer of the University of Alberta where she directs the Canadian Ice Core Lab.

This particular depth is remarkable considering Mount Logan is outside of the polar regions. Beyond this, the depth of the core matters for a number of reasons.

Simply put, “The depth of an ice core correlates with age - that is, the deeper we go, the farther back in time we go,” Criscitiello said. But, “it's not that the oldest parts of ice core records are necessarily the most valuable. The whole record is valuable, and the bottom ice is only valuable in its context within the rest of the record.”

The additional value of Mount Logan’s core comes in the fact that “it is likely that no one is going to go up there and drill again,” she said. “It’s very very hard to pull off,” and thus, “getting that oldest ice is very critical.”

Criscitiello recalled the time when glaciologists uncovered 16,000-year-old ice core data from the North Pacific, an area of the Earth scientists care a lot about for climate dynamic reasons. Yet, it’s also an area researchers “don’t have many long-term records from,” she said.

The reason? There are not very many ice cores you can get out of the North Pacific. Because of that, at the time of the 16,000-year-old ice core drilling, the news was, in the climate world, “totally Earth-shattering,” Dr. Criscitiello aptly said.

“It taught us things that we didn’t know about climate variability in the North Pacific, and how that variability is unique.” Now, with perhaps 30,000 years worth of ice core data, climate scientists can potentially learn so much more.

Looking from a big picture standpoint, peering down on the world from the top of the mountain’s peak, ice cores allow us to predict the future of things like sea level rise. Ice cores are one of a couple of ways to predict this, and to Criscitiello, they are the most powerful and high-resolution tool we have.

Scientists can use the ​​gas bubbles, pollen, dust particles, trace elements, and isotopes found in the cores to reconstruct the planet’s past, specifically looking at climate and air composition.

“They give us a really long-term perspective of what natural cycles of climate variability look like and then we can look at our current epoch, the Anthropocene, the period where humans have an imprint, and see what differences there are and have some hope of predicting what’s to come,” the glaciologist said.

At the core of the data, however, ice from Mount Logan has more specific research implications. “It can be somewhat endless,” Criscitiello joked.

One implication she’s most excited about is the potential to reconstruct temperature. Looking at long-term temperature, “tells us something not only about global climate, but there’s information in an ice core that’s specific to the region that the core is from. So in this case, we anticipate learning something about climate and temperature history in the past, specifically in the North Pacific.”

In this core, the researchers will measure an entire suite of marine aerosols, which are ions that originated from the oceans. This part, in particular, digs into what Dr. Criscitiello calls her niche area of expertise: using novel marine aerosols to reconstruct sea ice in the past, prior to the satellite era of the 1970s.

The aerosols as Criscitiello uses them, are “signals coming from the ocean which get transported up onto glaciers, ice caps, and ice sheets. They tell researchers information about sea surface conditions that, before the satellite era, they “had no way of knowing.” Sea ice acts as a barrier between the atmosphere and the ocean. Thus, as Criscitiello explained, “big changes in sea ice in the past can help explain large changes in climate.”

The implications don’t end at sea ice. On the hotter end of the spectrum, this data can also tell scientists a lot about wildfires.

In ice core science, this is fairly new. Looking at specific chemical markers, scientists can fingerprint wildfire vegetation. These measurements will be able to mark changes in wildfire frequency over time. It can also tell the kind of vegetation that was burning during different periods in the past. These measurements are key to understanding wildfire frequency in the future.

The research this core could catalyze is nothing short of groundbreaking. For years, Mount Logan has been at the top of the priority list for Criscitiello and other glaciologists because not long ago, thousands of years' worth of Arctic ice core history vanished.

Five years ago, a freezer malfunction at the University of Alberta in Edmonton led to several thousand years of history evaporating. The malfunction was prior to Criscitiello being hired at the university. At the time, the collection was a part of the largest collection of ice cores from the Canadian Arctic in the world.

Valuable ancient ice was reduced to puddles and a vital part of the record of the region’s past climates and environments was lost. An ice core from the Penny Ice Cap on Baffin Island lost about a third of its mass, amounting to about 22,000 years of history. A core from Mount Logan lost 16,000. The New York Times called the event, “An Ice Scientist’s Worst Nightmare.”

“When that happened, in my mind it [the Mount Logan expedition] suddenly became a top priority,” Criscitiello said. “Not only as sort of a rescue mission of what was lost but to do better because that’s not the oldest ice that’s sitting up there.” The ice core Criscitiello and her team recovered more than makes up for what was lost.

For a long time, Alison Criscitiello was thinking about scaling Mount Logan. She started working to get the original seeds of funding for the project in 2017. “I worked on it for a long time before I met National Geographic. It was a target for me and in the minds of a lot of ice core scientists, but I like to think I was the right person to do it,” she said and joked, “just because I like to suffer I guess, and go to these places.”

Criscitiello first visited Mount Logan in May of 2021. as part of the Perpetual Planet Expeditions partnership between National Geographic Society and Rolex. With her climbing partner, geologist Rebecca Haspel, they traveled to conduct radar surveys of the summit plateau, searching for ideal ice core drilling sites for an expedition that would take place a year later. Specifically, they were analyzing the ice’s internal stratigraphy all the way down to the bedrock.

The 2021 expedition marked two significant milestones in that it was both the first high alpine radar survey expedition conducted solely by two female scientists and resulted in the installation of the highest weather station in North America. The weather station sits at a towering 18.5 thousand feet, making it what Criscitiello remarks as the highest weather station in North America. By a long shot.

National Geographic Explorer Dr. Alison Criscitiello repairs North America's highest weather station on Mt. Logan, Kluane National Park and Reserve. Credit: Leo Hoorn/National Geographic
National Geographic Explorer Dr. Alison Criscitiello repairs North America's highest weather station on Mt. Logan, Kluane National Park and Reserve. Credit: Leo Hoorn/National Geographic

Weather stations that communicate real-time data to an open access website every five minutes are few and far between, especially in high mountain areas, Criscitiello said. After being established, they tend to not last very long for the same reasons that they are rare: brutal conditions, extreme cold, and hurricane-force winds. They don’t get installed often because of how difficult it is to accomplish. Nevertheless, Criscitiello was surprised by how much it was used.

“I didn’t realize how valuable this particular weather station would be,” the mountaineer said. “When we can pull these things off, the data is valuable across various sectors.” The station’s impact was broad.

“It’s been accessed an unreasonable amount. Not just by scientists at all, but by a lot of local First Nations communities who live in the area, by Parks Canada, by independent climbers, by pilots, by all sorts of people who want to know what’s going on with the weather.”

The weather station was scheduled to be taken down this year at the end of the drilling campaign. But Parks Canada had other plans. Instigated by the agency, Criscitiello has received the option of keeping the station up for a minimum of five more years because they have seen the need it satiates. “It’s the local community access that really made them realize the value in it,” she said.

Criscitiello’s list of accomplishments runs much deeper.

Before relocating to Canada for a postdoctoral fellowship in 2014, Criscitiello was awarded the first Ph.D. in glaciology ever conferred by the Massachusetts Institute of Technology. Since becoming the director of the University of Alberta’s Canadian Ice Core Lab, she’s led glacial ice studies and expeditions across Canada's Arctic and Rocky Mountains, Nunavut, the Himalayas, Greenland, and Alaska.

National Geographic Explorer Dr. Alison Criscitiello flying to base camp in Kluane National Park and Reserve. Credit: Leo Hoorn/National Geographic
National Geographic Explorer Dr. Alison Criscitiello flying to base camp in Kluane National Park and Reserve. Credit: Leo Hoorn/National Geographic

One of these expeditions was to the Columbia Icefield in British Columbia. It is one of the few iconic water towers in the world, meaning the snow and ice accumulated there is a source of water for many areas below, including, Criscitiello said, where she resides in Edmonton.

In the Columbia Icefield, Criscitiello and her team were looking at environmental contaminants that get transported up onto the icefield and then melt out as temperatures warm; contaminants that can potentially reach the drinking water, she said in the previous interview.

Mount Logan, in comparison, is not a water tower but has vast control over the regional climate and beyond the Yukon Territory. The mountain holds a lot of importance in terms of the health of the ice and the amount of melting that’s occurring across the icefield ranges.

“It’s a place that’s very cold so you would intuitively think it's a place that’s immune to surface warming and climate change in general,” Criscitiello said. “But unfortunately there’s a phenomenon called elevation-dependent warming which has shown — even in the St. Elias — that places at higher elevation can be, in some ways, more prone to increases in temperature and they can actually experience greater warming than lower elevations.”

Mount Logan’s cache of ice is almost incomprehensible. The reserve, as Criscitiello describes, is an enormous bowl of ice, with 20 kilometers in length and 400 meters in depth. The area is in one of those “precarious zones,” where over the next century, Criscitiello predicts, we’ll see rapid warming. “It will have a huge impact because of what the landscape looks like,” the ice core scientist said.

That landscape is a canvas of blue and white, a backdrop to Mount Logan’s sea of subpeaks and deep, gaping crevasses. Ice stretches as far as the eye can see. In pictures, the snow and ice look like a shiny blanket draped over the mountain’s jagged crowns. The Yukon’s glaciated scenery is the type of image that pulled Alison Criscitiello into the world of glaciology.

“I got into the kind of research I do because I fell in love with the places,” she said. After falling in love with recreation, climbing, mountains, exploring cold places, and the adventure of it all, “I wanted to understand them better,” she said.

But these places are rapidly changing.

As the evidence grows that warming — caused by levels of greenhouse gasses in the atmosphere — is amplified at higher altitudes, the world’s highest mountain ranges are warming at speeds outpacing that of their lowlands. As shown in a 2020 study published in the Journal of Climate, the surface air temperature in St. Elias Mountains warmed at a rate approximately 1.6 times larger than the global warming rate between 1970 and 2015.

This point was further drilled in years earlier by a December 2012 study. The study, published in the journal The Cryosphere, used survey maps of the Alberta-British Columbia border from 1903-1924, aerial photographs from 1982 and 1987, and satellite images from the early 2000s to document changes in the central and southern Canadian Rockies.

Their results were Earth-shattering.

Over the past 90 years, the total glacierized area has been vastly vanishing, with 154 of 660 glaciers disappearing and 124 glaciers fragmenting into multiple ice masses. While the majority of glaciers disappearing are small — as they are more at risk than larger ones — the study found that the higher rates of glacial change coincided with higher temperatures and lower-than-average rain. The researchers found a similar glacial retreat pattern in the Columbia Icefield where Dr. Criscitiello studied. They concluded that since 2000, the rate of glacial retreat and loss has accelerated with thinning held at a constant.

The need for quickly using ice cores to archive the history of Mount Logan is put eloquently in a Canadian Geographic essay written by one of Criscitiello’s expedition partners Zac Robinson, earlier this year.

Robinson writes in the essay’s conclusion, “And so the race is on to document — and learn from — 30,000 years of climate history before even Mount Logan begins to give in, the melting ice releasing the Earth’s secrets before we have a chance to learn from this last icy stronghold.”

National Geographic Explorer Dr. Alison Criscitiello takes in the view from the summit plateau of Mt. Logan, Kluane National Park and Reserve. Credit: Leo Hoorn/National Geographic
National Geographic Explorer Dr. Alison Criscitiello takes in the view from the summit plateau of Mt. Logan, Kluane National Park and Reserve. Credit: Leo Hoorn/National Geographic

Retaining hope in the face of a slow, sedated melt may seem like an even more strenuous feat than scaling the highest point in Canada. But what gives Criscitiello hope for the future are those who will come after her.

Over 15 years ago, her colleague Erin Pettit started a US program called Girls* On Ice, an initiative under the umbrella organization Pettit founded known as Inspiring Girls Expeditions. Before moving to Canada, Criscitiello was a long-time reader of applications for the program. The program is free with a goal to have zero barriers. But because of that, funding is difficult and there are very few spots available. As Criscitiello put it, despite many Canadian applications, those girls rarely, if ever, got selected. Thus, upon moving to Canada, Criscitiello worked with other Canadian women to establish a sister program. The program is called Girls* On Ice Canada, and focuses only on Canadian participants, mostly from First Nations, Canada’s Indigenous population.

“It’s the most important thing I do,” the mountaineer said, “And it’s not even my job!”

She started the program by thinking a lot about her own privilege. “I grew up in an upper-middle-class family outside of Boston,” she said, “I’m Jewish and queer, but I’m white, and as a privileged white person I think I’ve only been able to do what I do because of that. I have no idea if I would have landed where I’ve landed if I didn’t have all the opportunities I had growing up.”

So, she hopes that through Girls* On Ice Canada, she can help ease barriers in front of female-identifying high schoolers interested in glaciology, environmental science, STEM, and nature in general; a passion that can be expressed through the sciences or arts. To Criscitiello, it does not have to be confining or traditional, as long as participants are building confidence.

“It will truly have a life-changing impact on the trajectory of their life hopefully,” she said.

The program has been running for four years, serving new immigrants and First Nations members, and extending to other provinces and territories. Over those four years, it has grown largely. In its first year of funding, Criscitiello was able to arrange one expedition in Revelstoke in British Columbia. This year, for the first time ever, they have been able to arrange three expeditions. The expeditions are in the Kootenays and the Yukon, tripling the number of participants they are able to take.

Being surrounded by men, both in the lab and in the mountains, also inspired this program. Having a daughter now has made it all the more personal. What gives Criscitiello hope for the future is that in a couple of decades, someone like her isn’t the only woman in the room, or rather, the mountain range. “I’ve seen a huge change in these worlds that I’m in,” she said, “And I really hope this trajectory I’m seeing continues.”

“We’re headed in the right direction. The world just needs more time.”


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