Researchers: Small Colorado glacier could melt in 20 years

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Posted: Jan 12, 2016 4:44 PM

DENVER (AP) — DENVER — A small glacier in the mountains west of Boulder, Colorado, could disappear in about 20 years because of regional climate warming and drought, and similar thawing could be underway elsewhere in Colorado's high country, researchers said Tuesday.

A severe drought and high temperatures in the early 2000s caused a rapid loss of ice from Arikaree Glacier and from permafrost under the alpine tundra, said Mark Williams, a University of Colorado geography professor and alpine researcher. A long-term warming trend in the West has prolonged the melt-off, he said.

The regional warming trend could be related to global climate change, but that's hard to determine, Williams said.

"You can certainly make an argument that it is," he said.

Williams is part of a team that studied Arikaree Glacier, permafrost and rock glaciers in Arapaho-Roosevelt National Forest near the Continental Divide. Permafrost is frozen soil a yard or two underground. Rock glaciers are covered with rock and other debris.

The melting permafrost has been seen in an increase of water flowing out of the mountains in late summer and autumn over the past 20 years, Williams said. The runoff continued after the winter snowfall had melted, telling researchers it was from permafrost.

Arikaree Glacier has been thinning by about one yard a year for 15 years, Williams said. The glacier covers about 22 acres, roughly 17 football fields. Nearby Arapaho Glacier is four or five times larger.

The city of Boulder takes some of its drinking water from the area studied by the team, but officials said the city has other sources as well.

"I would not say it's cause for alarm, but climate change and climate change scenarios in general is something that we're very closely paying attention to," said Joe Taddeucci, water resources manager for Boulder's Public Works Department.

The University of Colorado has been collecting data in the area since the 1940s. It has two research stations near Arikaree Glacier on Niwot Ridge, one at 10,025 feet above sea level and one at 12,300 feet.

Few other locations in the state have such a long history of study, Williams said.

The effects documented on Niwot Ridge are probably happening elsewhere in the state's high country, he said.

"We've made a case many times that the research ... is representative of the Colorado Front Range, in many cases of larger alpine areas in Colorado," Williams said.

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