Student presentation explores what lay beneath Shakes Glacier

The Mendenhall Glacier in November 2025. (Jasz Garrett / Juneau Independent file photo)

By Leilani Combs

Wrangell Sentinel

Glaciers are in the public eye following the glacier collapse in Nepal and flooding in Juneau last month. These ice giants are as part of the Alaska landscape as salmon or bears, but their scale and remote nature make them difficult to study, leaving them as one of the more mysterious natural phenomena. 

On Sept. 9, student scientists from the Wrangell High School Shakes Glacier monitoring team and University of Oregon graduate student Victoria Benson gave a presentation on their research. The high school students have been monitoring the glacier since 2011, while Benson began her work in 2023. Together their work showed how the glacier has changed over time and mechanisms impacting its behavior today.

“What is a glacier? A glacier is a large ice snow rock sediment, and often water moves from the land and moves down slopes,” said Jordan Hayes, a high school junior.

About 40 residents attended the talk about the glacier that lies approximately 30 miles east of Wrangell, up the Stikine River. The glacier drains from the Stikine Icefield and terminates at Shakes Lake. It is one of an estimated 100,000 glaciers in Alaska.

When Benson asked the crowd at Wrangell's Nolan Center how many of them had ever visited the glacier, the majority raised their hands.

The high school monitoring program was started in 2011 by Eric Yancey and Jenn Miller-Yancey as a collaborative effort with the school, the borough and the U.S. Forest Service Wrangell Ranger District.

The program’s monitoring has captured the glacier receding more and more each year.

“The glacier has receded about 10,000 feet, or 1.9 miles, since 1999 through 2023,” said senior Andrei Bardin-Siekawitch. “It has (receded) 7,500 feet since 2011, when the Stikine River glacier survey started.”

He went on to say that they were able to calculate that the glacier is receding at an average rate of 420 to 470 feet per year.

University of Oregon graduate student Benson’s research focuses specifically on glaciers that terminate into a lake, rather than oceans, which brought her to Southeast Alaska.

Her work has been supported by collaborators at the University of Alaska Southeast and by the Yanceys, who help to provide transportation to the glaciers and support her surveys in addition to the glacier team’s work.

Benson shared that sea levels are rising and that glacier melt is contributing to that rise. She said that the research shows that while marine glaciers are losing mass, lake-terminating glaciers have lost a lot more mass by comparison.

“It begs the question: What is happening at these lake-terminating glaciers?” Benson said.

To look for the answer, she and her collaborators compared the behavior of two glaciers, Mendenhall, in Juneau, and Shakes. 

She said that because the lakes don’t have massive outflows where the water pours into another system like the ocean, you can pretty well determine how much the system is heated or cooled by the atmosphere and sun versus the input of cold water from the glacier.

They then mapped the topography underneath the lakes to better understand what characteristics might be at play.

“We can collect water depth by having basically a big fish finder or a sonar that can tell us how deep the water is,” Benson said.

They then measured the water temperature and how much sediment was suspended in the water column at different depths to build a temperature profile of the lake. 

Their mapping showed that a sill, or a sort of vertical barrier, effectively divides Mendenhall Lake into two smaller lakes beneath the surface. This allowed them to only focus on the side closest to the glacier.

By monitoring it throughout the summer, Benson said that the water became cooler throughout the season. Usually, a lake will warm throughout the summer due to sun exposure. Because it was instead cooling, they were able to assume that increased summer glacier melt was cooling the system.

The interesting thing is that Shakes Lake showed the opposite behavior. The lake warmed through the season as would be expected in a non-glacier lake. Although their maps appeared to show the other side of the lake away from the glacier was slightly warmer, there was not a significant difference.

But Benson clarified that did not mean that the glacier was not melting. She said that it was possible that the lake is just too big to have its temperature dramatically changed by possible glacier melt.

“This lake is very impressive. It’s about six miles in length. … The deepest part is about 800 feet,” Benson said, “and it’s 1.2 cubic kilometers in volume (about 1.5 billion cubic yards), which compared to Mendenhall is a lot bigger.”

To address whether there is melt happening, they were able to map the front of the glacier using drones which showed caves forming in the base of the glacier face. That, along with the mildly cooler temperatures near the face and increased sediment in the water, she said, allowed them to say that there was likely glacier melt coming out through cracks at the base of the glacier.

“Because of these volume differences and the size of these lakes, it seems can have such a big impact on how it’s affecting the glacier itself,” Benson said.

• This article was originally published by the Wrangell Sentinel.