Shrinking Bylot Island glaciers tell story of clim...( CHAMPAIGN lll. The U.S. Geological ...)

CHAMPAIGN, lll. The U.S. Geological Survey has released the results of a long-term study of key glaciers in western North America, reporting this month that glacial shrinkage is rapid and accelerating and a result of climate change.

University of Illinois geologist William Shilts spent nearly two decades studying glaciers on Bylot Island, an uninhabited island about 300 miles southwest of Thule, Greenland. He, his students and other geologists who followed in his footsteps have chronicled the decline of several Bylot Island glaciers. Photos of the island from the 1940s to the present offer a vivid picture of the changing glaciers and the forces that shape their retreat.

For a slide show of the glaciers from 1948 to the present, please go to: http://news.illinois.edu/slideshows/bylot_glacier/index.html.

"I started working in the late 1970s on Bylot Island, which is about the size of New Jersey," said Shilts, the executive director of the Institute of Natural Resource Sustainability at Illinois. "Bylot Island is like a miniature North America. It has a very old crystalline rock core that's covered with ice and glaciers, and it's surrounded by younger rocks."

"As time went on it became very evident that the glaciers on Bylot Island were, for the most part, retreating, shrinking, melting faster than ice could be produced," he said. "For whatever reason, the summer melting was exceeding the winter snowfall."

With a perspective spanning more than 4 billion years, geologists have a unique point of view on current climate changes. They know that ice ages and glacial retreats are common because these events leave indelible marks on the land.

To a geologist's eye, the color of rock near a melting glacier, the pattern of scars on its surface or fissures at its edges, the shape of a mound of gravel left behind or the pattern of snow and ice
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