©2008 WGBH Educational Foundation. All Rights Reserved.

Third party materials courtesy of National Snow and Ice Data Center, NOAA/Rear Admiral Harley Nygren, NOAA/Mike Dunn, NOAA/Commander John Bortniak, NOAA/Captain Budd Christman, Woods Hole Oceanographic Institution, WHOI/Henry Dick, Genevieve Anderson, L. David Mech, Joe Mastroianni/NSF, Steven Profaizer/NSF, James Roth/University of Delaware/NSF, USGS/Richard Waitt, USGS, Australian Antarctic Division/Robert Reeves, National Park Service, Library of Congress, and NASA/Ben Holt Sr.