MONTREAL -- Timelapse footage of a fast-moving glacier in Alaska's Denali National Park has been released by scientists, who describe the phenomenon as a "glacial surge."
It's the first time the Muldrow Glacier has moved at such a pace in the last 64 years.
According to the park's website, a glacial surge is "a short-lived, cyclical event where ice within a glacier advances suddenly and substantially, sometimes moving at speeds 10 to 100 times faster than normal."
It can be caused by "the interplay of ice buildup at higher elevations over time, and supply of the ever-present meltwater to the base of a glacier."
This "river of ice" is now flowing 10 to 20 metres per day, according to satellite and aerial image analysis. This is 50 to 100 times faster than the daily flow rates over the last 60 years.
Scientists say they were expecting the event, as the glacier has a history of surging approximately every 50 years.
The last time the Muldrow Glacier surged, in 1956-57, it advanced over about 6.4 km.
