

Chinstrap penguins walk on the ice between South Sandwich Islands and South Georgia in Antarctica. Newscom
Ministers and represenatives from about a dozen nations attend a fact-finding visit to the area around Norway's Troll Research Station on Feb. 23, 2009. Here, they tour the ice sheet below the Judulsessen massif of rock towers in Antarctica. The ice sheet sitting atop Antarctica is so vast, up to 3 miles (5 km) thick in some places, that it pushes Earth's crust thousands of feet down. If all that ice melted, it would raise sea levels globally by an estimated 230 feet (70 meters). Charles J. Hanley/AP
A crabeater seal rests on a floating chunk of ice in Antarctica. Ninety-eight percent of the crabeater's diet is Antarctic krill, despite its name they do not eat crab. The seals consume over 80 million ons of krill each year in the ice pack around Antarctica. Corbis/NEWSCOM
An ice pack floats in waters off Antarctica. Corbis/NEWSCOM
This digital composite image of an iceberg in Antarctica shows both the top arch portion of the iceberg, and the underwater structure and shape, which is sculpted by the movements of the sea. NEWSCOM
From the BBC's series 'Planet Earth,' Cameraman Wade Fairley films emperor penguins in Antarctica in this 2005 file photo. Frederique Olivier/Discovery Channel/BBC/FILE
The base of an Antarctic iceberg is seen here sculpted by the water. NEWSCOM
A grounded iceberg is seen near a penguin rookery in this photo from the Australian Antarctic Division. Australian Antarctic Division/Reuters
Chunks of icebergs, Bergy Bits measuring 3-16 feet in height and 16-50 feet long, are seen in front of an ice pack in Antarctica. NEWSCOM
Antarctica is 99.7 percent covered with ice, and with warmer temperatures, glaciers are calving more icebergs now than before. Members aboard the three-masted Europa (not shown) sailed off the coast of Antarctica and observed the effects of climate change on the continent. George Toombs
Members of the Applied Physics Laboratory Ice Station clear ice from the hatch of the Los Angeles-class submarine, the USS Annapolis, after the sub broke through the ice while participating in an exercise on March 21. Tiffini M. Jones/US Navy/Sipa Press/NEWSCOM/FILE
An oddly shaped iceberg is seen in the seas off of Antarctica. Corbis/NEWSCOM
In 1966, Lindblad Expeditions became the first to offer expedition travel to Antarctica. Lindblad has raised nearly $600,000 to support Oceanites, a Antarctic-focused non-profit organization that gathers information on penguin populations and the impacts of tourism. Here, Lindblad guests explore the Antarctic waters by Zodiac as penguins are seen nearby. Courtesy of Ralph Lee Hopkins/Lindblad Expeditions/FILE
An iceberg is seen in the Errera Channel at Culverville Island, Antarctica. Typically only one-tenth of the volume of an iceberg is above the water due to the density of the ice. Susan Walsh/AP