Alaska's glaciers retreating and melting, book says

U.S. News and World Report LiveScience reports on the U.S. Geological Survey's (USGS) new book that documents the thinning and retreating of all Alaska's glaciers.

"The new book on Alaska's glaciers used satellite images, aerial photos, maps and other studies to document the retreat of the glaciers, which began as early as the mid-19th century. Some glaciers have even disappeared since being mapped in the mid-20th century, the report found."

Read the full story: Most Alaskan glaciers retreat and thin