Mapping Alaska’s glaciers from above
Maya Westcott
Aug 9, 2024
Nestled within Alaska’s Wrangell-St. Elias National Park and Preserve, the largest national park in the United States, the Kennicott and Root glacier complex draws more than 50,000 visitors every year. This region, accessible by one of only two roads in the park, offers a unique opportunity for hikers to explore the icy surface of Root Glacier. However, like many other glaciers around the world, looking beyond the park’s stunning views reveals pressing environmental concerns around the thinning and retreat of the glacier system.
To better understand the region’s current and future conditions, researchers from Carnegie Mellon University, in collaboration with the National Park Service, University of Alaska Fairbanks, and University of Arizona, launched a project to map the glacier’s thickness and bedrock elevation using two types of ice-penetrating surveys – from the air and on the ground.
Beginning on foot, CMU’s Brandon Tober and team donned skis to survey the four kilometer lower section of Root Glacier where visitors access the park. This approach, while limited in range, collected data on the most trafficked area of the glacier system and later served as ground-truth validation for the second phase of surveys from above.
"Traditional ground-based ice penetrating radar surveys are very labor-intensive,” said Tober, a postdoctoral researcher in the Department of Civil and Environmental Engineering. “With a helicopter-borne radar, we were able to cover approximately 550 kilometers of landscape in three days.”
Suspended from a bright orange helicopter, the four-pronged, drone-like sensor flew over both Kennicott and Root Glaciers in a serpentine pattern, using radar sounding to capture detailed measurements of the ice thickness and bedrock elevation below.
The data collected from both surveys will help predict how the glacier will evolve in the future, construct detailed regional maps, and better understand the glacier’s marginal lakes and their subsequent threat: outburst floods.
The surveys will not only enable us to further scientific understanding of glacial retreat, but will also help to assess potential future hazards to the downstream community and infrastructure.
Brandon Tober, Postdoctoral researcher, Department of Civil and Environmental Engineering
“Outburst floods occur when dammed lakes fed by glacial meltwater are released. They can be detrimental to towns in close proximity, like McCarthy, Alaska,” said Brandon Tober. “So, the surveys will not only enable us to further scientific understanding of glacial retreat, but will also help to assess potential future hazards to the downstream community and infrastructure.”
The results of these surveys will ultimately help inform the National Park Service of potential hazards to existing and future infrastructure developments including roads, pedestrian bridges, and trails. Until then, Tober and his team – including David Rounce, assistant professor of civil and environmental engineering, Martin Truffer from the University of Alaska Fairbanks, Jack Holt from the University of Arizona, and Mike Loso from the National Park Service – remain dedicated to analyzing their radar data to better understand what the future holds for Wrangell-St. Elias National Park and the Kennicott and Root glacier complex.