Glacier melting at fastest pace in centuries

One of the USA’s tallest glaciers is melting at the fastest pace in 400 years, a new study reports.

The study said melting on Mount Hunter in Alaska’s Denali National Park can be linked mainly to rising summer temperatures in the region.

“We have not seen snow melt like this in at least four centuries,” said study lead author Dominic Winski, a glaciologist at Dartmouth College.

New ice cores taken from the top of Mount Hunter show summers there now are least 2 to 3 degrees Fahrenheit warmer than they were during the 18th, 19th and early 20th centuries. Specifically, the ice core record shows 60 times more snow melt occurs today than did 150 years ago.

Ice cores are good records of past climate because the water, snow and air in the ice contain evidence of atmospheric conditions over hundreds to thousands of years, the Byrd Polar Research Center said. The seasonal snowfall and its gradual change to ice provide an annual record of snowfall amounts and atmospheric conditions throughout the year.

The scientists drilled two ice cores that gave a record of the climate there going back to the mid-17th century.

The warming in Alaska coincides with warming in the tropical Pacific Ocean, according to the study.

“We suggest that warming of the tropical Pacific Ocean has contributed to the rapid warming on Mount Hunter by enhancing high-pressure systems over Alaska,” the study authors said.

Deke Arndt, the head of NOAA’s Climate Monitoring Branch, said that “in the context of a changing climate, the Arctic is changing more rapidly than the rest of the planet.”