North American Glaciers Are Shrinking Fast

Three chief glaciers–Alaska's Gulkana and Wolverine and Washington state's South Cascade–are shrinking dramatically, according to a U.S. Geological Survey study released last week. These glaciers have been acutely measured since 1957, and scientists say their changing shape indicates a warming climate.

"These are the three glaciers in North America that have the longest record of mass change," wrote Shad O'Neel, a glaciologist in Anchorage. "All three of them have a different climate from the other two, yet all three are showing a similar pattern of behavior, and that behavior is mass loss."

The USGS study compared measurements of snow and ice mass through time, and found that melting has occurred faster than buildup, meaning the glaciers have shrunk drastically, especially over the past 15 years. While O'Neel says that doesn't necessarily prove global warming, "it certainly says that the place where these glaciers are, the climate is not supportive of healthy glaciers anymore." —Alyson Sheppard

Read the Reuters story here.

Read the Department of the Interior report here. 

Watch USGS video of South Cascade Glacier aerial photos from 1928 to 2006 here. 

And check out NG Expeditions Council Grantee James Balog's Extreme Ice Survey here.