On the evening of 5 August 2013, a startling event occurred deep in the remote interior of the United States’ largest national park.
On the evening of 5 August 2013, a startling event occurred deep in the remote interior of the United States’ largest national park. A half-kilometer-long tongue of Alaska’s Flat Creek glacier suddenly broke off, unleashing a torrent of ice and rock that rushed 11 kilometers down a rugged mountain valley into the wilderness encompassed by Wrangell–St. Elias National Park and Preserve.
After National Park Service geologist Michael Loso documented a similar event in the same location in 2015, he recruited Mylène Jacquemart, a Ph.D. student at the University of Colorado Boulder, to investigate. “We were aware of glacier detachments that had happened in Tibet, Russia, and Argentina, but started out thinking we were investigating a regular landslide,” says Jacquemart. “Then we noticed that the entire glacier was missing.”
The results, published in Geology, indicate the Alaskan detachments occurred at the height of the summer melt seasons and suggest these highly destructive events could occur more frequently in a warming world.
After National Park Service geologist Michael Loso conducted preliminary research that ruled out a seismic trigger for these events, he, Jacquemart, and other experts began a research project to investigate what had happened at Flat Creek. The team used a variety of tools, including satellite imagery, field measurements, digital elevation models, and meltwater modeling, to piece together the sequence of events. “This project was a real sleuthing challenge,” says Jacquemart, “and the pieces finally fell into place when we discovered the bulge on the Flat Creek glacier.”
Read more at Geological Society of America
Photo credit: 272447 via Pixabay
