Glaciers persist in ‘perfect situation’
ESTES PARK – While their southern neighbors are shrinking, glaciers in Rocky Mountain National Park are making a stand.The four small park glaciers, which provide late-season runoff to park streams after snow has melted, haven’t changed dramatically since the 1930s based on photo comparisons, according to work by independent researcher and geologist Jon Achuff.Their persistence is likely the result of a “perfect situation” that includes plenty of shade, snow blown in from the west side of the Continental Divide and relatively steady cold temperatures.”The combination is just such that it’s a protected spot,” said Achuff, who presented his findings earlier this month at the Rocky Mountain National Park research conference.
Recent studies by the University of Colorado suggest the Arikaree and Arapaho glaciers – Arapaho is the state’s largest – in the Indian Peaks Wilderness south of the park have lost 60-plus feet of ice thickness since 1960. Those losses have been largely chalked up to the warming climate and an extended melting season.But the glaciers Achuff studied in Rocky Mountain National Park haven’t shown the same retreat.”We do know there’s climate change taking place, and these are not reflecting that,” Achuff said. “They’re really lousy indicators of climate change.”The biggest reason the glaciers are holding steady is the amount of shade they get. Air temperature might be rising, but the glaciers in Rocky get little direct sunlight, and that keeps them from melting faster than they can replenish.
But Achuff and other researchers can’t compare the glaciers’ survival to temperature changes because the park lacks such data.”That’s a hole that’s pretty glaring,” said Judy Visty, the park’s research administrator and an ecologist.Still, the results surprised Achuff.”Everyone’s talking about glaciers melting,” Achuff said. “It’s really easy to make the assumption – that’s what’s happening here.”
But the park’s glaciers are so small – Achuff estimates each is about 20 acres – that they’ll respond more to extremely localized climate patterns than they will to global trends, said Nel Caine, a geography professor at the University of Colorado who has worked in the Arikaree Valley since 1968.”They’re very small features,” Caine said. “If they’re going to respond, they’ll respond to the local environment.”Vail, Colorado