WATCH: Rare Active Layer Detachment Witnessed in Denali National Park
Have you ever witnessed an “active layer detachment” in action? That’s okay, you’re about to become among the very first. Turns out few people ever have, according to Denali National Park.
What you’re seeing in this video taken by Brian Howard of Northern Arizona University is the surface layer of a hillside in Denali breaking off and sliding downhill on the “greased butter” of a thawing underlying permafrost layer. It occurred in an area of the park that burned in a wildfire in 2013 that is the subject of an NPS research collaboration with Northern Arizona University as part of a NASA research program called the Arctic and Boreal Vulnerability Experiment (ABoVE).
NPS researchers suggest this particular slide is likely related to the effects of fire in degrading permafrost and killing tree roots that help hold a slope together. But conditions were probably exacerbated by an unusually warm winter and early break-up, high summer precipitation, warm temperatures and increased permafrost thaw dynamics that have been occurring across Alaska and high latitudes generally.