TORONTO -- A glacier on Alaska’s Denali is on the move and picking up speed according to the National Park Service.
The Muldrow Glacier extends high up into North America’s tallest peak, and a recent flyover revealed cracks and crevasses in its surface indicating that the glacier was surging. A glacier surge is a cyclical event when the glacier will abruptly move a significant amount at 10 to 100 times the usual speed.
Scientists have been waiting for the Muldrow Glacier to surge for years. Previous studies indicated that the glacier would surge every 50 years, and its last one was in 1956-57.
The glacier is 62 kilometres long, starting high up on Denali’s northeastern slope, and is a popular climbing route for mountaineers. After the surge, it may be impossible for climbers to use the route because of deep crevasses that may linger for years. Reports indicate that this was the case after the surge in 1956-57, at which time it moved 6 kilometres.
The hotly anticipated surge is being closely monitored by scientists, who say that it is moving 10 to 20 metres per day, which is 50 to 100 times faster than it moves when it is not surging.
According to the U.S. National Park Service, only about one per cent of the world’s glaciers surge. Many of the glaciers in Denali National Park are surging glaciers.
After waiting six decades for the Muldrow Glacier surge, scientists are excited to track and detail the surge. Researchers are conducting aerial imaging and mapping, and a sound station has been set up to record what all the moving ice sounds like.
While researchers aren’t positive when the surge will end, based on the last one, they think it may be only halfway. In 1956-57 Muldrow Glacier moved 6.6 km before slowing to it’s quiescent phase. The ice has only moved 3.1 km so far during this surge.
Visitors to the park this summer are advised to stay off the glacier as the ice will be unstable.
