Crampons crunched in the mountain snow. Afternoon sun shone through wispy clouds as Simeon Caskey surveyed the glacier that swept skyward before him, from the base of the Middle Teton to high on its north face. He turned to his climbing partner.
“You want to start low?” he asked.
The Grand Teton National Park ranger, who leads the park’s physical sciences branch, trudged across the glacier’s base beside Jenny Lake Climbing Ranger G. R. Fletcher. They and the rest of their team had ventured 6 miles into the park that early September morning to document the ebb and flow of the Middle Teton Glacier. And, obviously, for the fun of it.
“I just show up ’cause I like to walk on ice,” Fletcher said.
The two were decked in the grays and greens of National Park Service attire, each wielding a scepter of science: poles, taller than them, mounted with GPS systems called Trimbles. They traversed the glacier, tracing a massive grid and pausing every 10 meters to let the devices home in on each point.
This kind of work is going on around the world as a warming atmosphere envelops the planet. With ice melting everywhere from the Andes to the Himalayas, researchers are striving to understand just how quickly the Earth’s glaciers are disappearing.
The Tetons are home to 11 of them, all of which have retreated since they were first surveyed in the late 19th and early 20th centuries. Park personnel in recent years have begun to seriously study the health of five: Teton, Schoolroom, Falling Ice, Petersen and, of course, Middle Teton.
Visible from the highway and located along the most popular route up the Grand Teton, the Middle Teton Glacier is familiar to many. But the closer you get, the more stunning and otherworldly it appears.
It’s a harsh, scarred landscape. Dirt and rock debris litter the otherwise white surface. Meltwater carves the ice, in some places as tiny rivulets, trickling silently; in others as foot-wide streams, crashing against the ice and snaking back and forth in deep channels. High up, jagged crevasses tear across the glacier’s steep face.
Each year park scientists trek up to this spot — plus those previously mentioned — and collect data that will reveal how much and how rapidly the glaciers are melting.
“I would say it’s extremely important,” Caskey said, waiting for his coordinates to load. “For one because of their importance to the downstream ecosystem.”
Acting as reservoirs, glaciers keep water flowing through the driest months and in turn maintain the health of plants and animals throughout the mountains and valley below.
“And then, secondly,” he went on, melting ice rushing around him, “they are a great manifestation of what climate factors are taking place on a longer scale.”
Searching for signs
Another member of the team, Reba McCracken, glaciologist by training and self-proclaimed nerd by nature, stood at the edge of the glacier. While her colleagues crisscrossed up and down, back and forth over the ice, she had tasks of her own.
But first she heaved off her pack, grabbed a bottle and smiled: “I’m going to drink some meltwater,” she said.
Refreshed with the icy liquid, she wandered off to investigate one of the ablation stakes that had been planted in the glacier earlier in the year.
The stake, a segmented piece of PVC pipe, was stuffed into a hole in the snow at its peak depth. This year it was placed on the first of June, and as the snow around it melted it became exposed, showing McCracken how many meters have turned to water in the months since.
“One, two, three,” she said, counting the sections. “Four, five, six, seven.” Nearly seven and a half meters, or just under 25 feet.
“This was all under snow, which is pretty crazy,” she said.
But is that amount normal or abnormal?
“We don’t know,” she said with a laugh. “The dynamics of this glacier are hard to know.”
And more so considering the dearth of data. Sporadic monitoring over the decades offers some insight into long-term patterns in the Teton glaciers, but not enough to glean anything with much certainty. It’s only since 2015 that park scientists have made an earnest attempt to understand their workings and condition, and it could take as much as a decade before they start drawing conclusions.
Much of the equipment for the work is purchased through a partnership with Grand Teton National Park Foundation.
“Our glacier program’s super young,” McCracken said. “When your data only extend that far back, it’s hard to make sweeping statements.”
For now she has little to go on. Based on what scientists have predicted for other glacier-rich areas, however, their future is bleak. In Glacier National Park, for example, some estimate the world-famous ice could be gone within the next couple of decades.
But, McCracken noted, other research shows that although glaciers are by and large receding, they’re doing so at a slower rate over time.
As they shrink, the logic goes, they retreat into the cool, shady slopes of the mountains they inhabit, where they’re protected from the worst of the melting. In fact, she said, judging by the rate of retreat back in the 1800s the glaciers should be gone already.
“It’s just amazing that they’re still here hanging on,” she said.
Regardless, she hopes that with the measurements her team is now consistently collecting, they’ll be able to learn more and see how the glaciers fit into established climate models. Besides the GPS coordinates and ablation stakes, they also set up time-lapse cameras and compare modern-day photos with those taken over the years, to gauge the extent of the ice across time.
“These glaciers are in a climate regime that is warming,” she said. “That is probably ultimately bad news for them, but there are some factors that could help them stick around longer. That’s what we’re trying to suss out.”
For the love of ice
A Nashville, Tenneesee, native, McCracken grew up far from the glaciers of the West and went to university with an interest in economics. It took a summer working in Alaska for her current passion to bloom, and for her to ditch her first major and switch to studying glaciology.
“I didn’t know anything about glaciers,” she said. “I just got really obsessed with them.”
It’s easy to see why after witnessing one up close. The sheer natural force of a flowing glacier, the way its icy bulk can mold a landscape effortlessly — and, from a human perspective, invisibly — is mystifying and magnificent.
The glaciers of today’s Tetons are not the same ones that shaped its peaks and canyons, though. The remnants of those earth-shifting behemoths can be seen, for example, in the hills around Bradley and Taggart lakes — ancient moraines deposited by the conveyor belts of glaciers that flowed here during the Pleistocene Ice Age more than 10,000 years ago.
The modern glaciers formed much more recently, during the Little Ice Age that lasted from about 1300 to about 1850. They are far smaller than their prehistoric counterparts, and some of McCracken’s glaciologist friends from Alaska poke fun at their size.
But even so, they are remarkable, and McCracken is far from the first to become entranced by them.
Joey Nadeau, a geographic information system specialist and the fourth member of the team, said that every time he has helped with glacier monitoring the park-goers they encounter want to know what they’re doing.
“It’s cool to see that people are genuinely curious about what’s in their parks,” Nadeau said.
McCracken recalled that she once even found the footprints of some inquisitive soul leading up the steep slope of the glacier to an ablation stake, and then back down — apparently not skiing or mountaineering, only satisfying a desire to know.
Glaciers are not the predominant features of Grand Teton National Park. But without them the ecology and topography of the cherished mountain range would change dramatically, and McCracken argued their loss would ripple across the many groups that love them — albeit for far-ranging reasons.
“It resonates with so many different people,” she said. “Whether it’s the ecologists who are psyched about their role in the ecosystem, or the skiers who are psyched to have something late-season to ski, or the people from Tennessee who come out here and say ‘Whoa, I’ve never seen a glacier before and I can walk on this one.’”
As she spoke, hikers and climbers passed along the moraine above Middle Teton Glacier. They craned their necks toward the scientific ballet unfolding below and, presumably, wondered at the spectacle.
“No matter who I end up talking to about what I do here,” McCracken went on, “they always seem interested and excited.”
This version of the article has been updated to add a sentence about the Grand Teton National Park Foundation partnership. — Ed.