After 18: Alaskan adventure

Soil sampling at Denali National Park.


Every year The MV Times asks recent high school graduates to write about their experiences after graduation. Lena Hanschka is a member of Colby College, class of 2021.

We flew out to the Kahiltna Glacier in Denali National Park, Alaska, on a clear day in early June. I was accompanied by Gabe Lewis, a geology grad student from Dartmouth College, and David Polashenski, another geo grad student at the University of Alaska, Fairbanks. The three of us filled the small twin-engine airplane with our winter mountaineering gear, along with the 300-pound ice core drill and enough food to stay for a month. From above, the glacier looked deceivingly small, and it wasn’t until we saw the cluster of tents that marked Denali’s base camp that we had some sense of scale for how massive the mountains surrounding us were.

The plane circled around and landed on the snow-packed runway. As soon as we stepped out, we began shuttling the hundreds of pounds of gear uphill a short distance to our camp. Within a few hours we had set up our kitchen tent and two sleeping tents, being careful to choose a spot away from the open crevasses in the ice. It was evening, but the sun still shone high above on the dramatic snow-covered mountain ridges.

During the next two days, we got acclimated to the higher elevation of base camp, roughly 7,000 feet above sea level. To become more comfortable traveling in roped teams with our skis, we skinned on our skis a few miles away to a small hill, and lapped it several times. We also practiced setting up the ice core drill, although the higher temperatures at base camp were not conducive to drilling, and it kept jamming.

Mount Hunter, with an elevation of 14,573 feet, sits just behind base camp on the Kahiltna Glacier, although it is rarely climbed due to the difficult ice-climbing routes up the steep slopes. The saddle of Mount Hunter is essentially a flat plateau, ideal for ice and snow sampling. While other areas of the snow and ice sheet are constantly moving, the plateau is stationary, preserving snow and dust accumulation dating back thousands of years. The snow and ice samples collected from the saddle can be used to help understand changes in the westerly winds by tracing the sources of the dust that has settled there over the ages.

Due to the high elevation of the saddle, roughly 11,000 feet, it was necessary for us to spend several days acclimating slowly so as to avoid altitude sickness. To get our bodies used to the changes, we planned a multiday ski trip up to an elevation of 11,000, following the climbing route up Denali. Because June is climbing season in the park, the mountain had over 500 climbers attempting to summit Denali while we were there, waiting for the right breaks in the weather to begin or continue their ascent. With the extreme temperature and weather variability characteristic of the mountain, most climbers take about two weeks to reach the summit, bringing extra supplies and food in case a storm blows in.

With this in mind, we started our acclimatizing ski trip with enough food and supplies to last more than a week, plenty of warm layers, tents, and sleeping bags. We traveled as a roped team for safety because of the danger of the many crevasses. Gabe led the way, with me clipped in about 50 feet behind him and David another 50 feet in the back. We each carried a backpack and towed a sled filled with gear weighing about 40 pounds. Because the route is pretty well-traveled, it was easy to ski along, following in the tracks of others. Throughout the trip, the weather was clear and sunny, and often got so warm during the day that we would stop and take a break during the hottest hours of the afternoon.

Our first day was pretty mellow: We skied 3.5 miles, gaining only 500 feet in elevation. We spent the night at 7,500 feet above sea level, savoring our instant mac and cheese and warm sleeping bags. In the morning, we broke down camp, roped up, and started our long trek up to camp two, located at 11,000 feet above sea level. The route went consistently up the entire day, and we skied over 3.5 miles, this time gaining 3,500 feet in elevation. As we moved higher up, the air grew increasingly thinner, making it harder to breathe. My sled started to feel as if it were made of lead, and each step on my skis was laborious. It was a difficult ascent, and we stopped frequently to rest.

As we came up over the final hill, I was startled to see how many tents were there, creating a little village bustling with climbers. We set up our tents and dug out a hole in the snow to serve as our kitchen/dining room/living room. Although we had stopped moving, I could feel my heart beating faster in response to the high altitude.

We spent the next two days relaxing in our snowy home. Climbers came and went, often making multiple trips to shuttle their heavy gear from one camp to the next. I took weather measurements, noting how perfectly situated the camp area was, with very little wind and relatively mild temperatures. We chatted with mountain guides, who were as interested to hear about our scientific fieldwork as we were about their adventurous stories on North America’s highest mountain.

After spending three nights acclimatizing at 11,000 feet, we were ready to head down to base camp. At first, skiing steeply downhill with the sleds full of gear proved rather challenging, but after several falls we got the hang of it, covering ground more quickly. We got back to base camp by midafternoon and settled in. The next day, I helped Gabe and David prep the equipment for the drilling, and gathered all the gear to be flown off the glacier.

In the morning, we packed everything for the helicopter that would fly Gabe and David up to the plateau where they would take the core samples. The Parks Service had determined that due to my limited mountaineering experience, it was unwise for me to accompany the team to the saddle of Mount Hunter, which is only accessible by helicopter or via a very challenging ice-climbing route.

As David and Gabe lifted off, I thought about how much energy goes into collecting scientific data. Our week on the glacier helped prepare us physically and mentally to collect samples in a remote, difficult-to-access location with unpredictable weather. But before flying out to Alaska, our team had spent weeks strategizing, preparing, reviewing gear lists, and figuring out the logistics of transporting ice cores from Alaska to New Hampshire without thawing. In Talkeetna, the small town where planes shuttle people on and off the glacier, we met many people who had witnessed firsthand the glacier changing each year, and were excited about what we were studying. They supported our work, and were eager to help out in any way they could, from discounting our flying rates to offering up freezer space in the local brewery.

The experience as a whole was humbling. The mountains are dramatic and beautiful, and we were constantly in awe of how breathtaking each view was. But they are also dangerous, with deep crevasses hidden beneath the snow and huge seracs of ice waiting to fall from steeper slopes. Like the climbers, we respected the mountains and marveled at their magnificence. And we hope that our work, in turn, will be appreciated not only by the local community, but also by the scientific community as a whole.

Back on Colby’s campus this summer, I worked for Dr. Bess Koffman, an assistant professor of geology at Colby College. In her geochemistry lab, we conducted various chemical extractions on dust and snow samples collected during the 2016 and 2019 field seasons. Once analyzed, these samples will add to the data documenting changes in the westerly winds through the process of dust fingerprinting (determining the composition and geographical source of materials frozen in the ice), as well as snow accumulation and melt data dating back thousands of years. Ice cores previously collected from the Mount Hunter saddle have already shown an increased snow accumulation and melt in the past 150 years. Collectively our field and lab work, funded by the Buck Lab for the Environment and Climate Change, will provide supporting evidence for many theories surrounding past climate change, and insight into the future.