The Muldrow Glacier, one of the five large glaciers that flows off the slopes of the Denali mountain peak in Alaska, is now moving 10 to 100 times faster than it was several months ago. A pilot first noticed the speed shift in early March, observing from the air a (relatively) sudden cracking of ice along the length of the glacier. And while officials have been expecting the sudden speed shift, it’s still a momentous event.
National Park Service
Earther reported on Muldrow’s newfound celerity, an event which marks a natural shift in the glacier’s pace of movement. Muldrow, along with only 1% of all glaciers, is a surge-type glacier; meaning it experiences a periodic “surge” in speed, ramping up by up to two orders of magnitude.
“Scientists have been anticipating the present surge for a while now, but no one knew exactly when it would happen,” the National Park Service (NPS) writes in a press release. “Now, 64 years after the last surge, the Muldrow Glacier is on the move again and scientists have begun a flurry of observations of the now rapidly flowing glacier.”
I feel privileged to play a small role in monitoring the #muldrowglacier surge. Big thanks to the NPS and UAF for the rapid and collaborative response! https://t.co/bGDXqTuTuw
— Christopher McNeil (@realTakuGlacier) April 7, 2021
Even though these surge events are well documented, scientists are still unclear as to their exact catalysts. Scientists believe the physical characteristics of a glacier—its shape, thickness, the terrain upon which it sits—likely influence the surges. As well as water from precipitation and melting infiltrating the glacier through cracks at its base. But what begins the cycle—from the slow “quiescent” phase to the surge phase, and then back—is still a mystery.
As for the impact of the event, it seems like it’ll mostly have to do with scheduling at this point. A thousand climbers have signed up to ascend Denali this year, and the surge may keep them from doing so. There’s also some potential for the surge to be deadly, as surging glaciers can crush people. Or melt rapidly, and flood entire settlements. Which means it’s definitely time for anyone in the area to (literally or figuratively) take flight.
National Park Service