Massive Crack Found in Pine Island Glacier

The Pine Island Glacier, known among experts as PIG, is one of Antarctica's five largest ice streams, and one of the most important ice fields in the world. During a study conducted at the location by NASA scientists, back in October 2011, a huge crack was found scarring its surface.

This is nothing but bad news, climate experts say, adding that the ice stream is responsible for draining an important portion of the massive West Antarctic Ice Sheet (WAIS). It is also responsible for keeping huge amounts of ground-based ice away from the oceans.

According to experts, the entire continent is largely divided between two major ice sheets, the East Antarctic one (EAIS) and the western one, the WAIS. While the EAIS is very large and largely stable, the WAIS is in constant motion, allowing about 10 percent of its mass to escape into the Southern Ocean via the PIG.

Together, the EAIS and the WAIS hold sufficient ice to cause a sea level rise of 57 meters (187 feet) all around the world. The only way of avoiding this scenario is to keep the ice contained at its current location, but global warming and climate change is making this increasingly difficult.

The crack in the Pine Island Glacier is just the latest in a series of symptoms affecting the Antarctic, which is the world's largest reservoir. The 80-meter (260-foot) wide gap spanned a length of 30 kilometers (19 miles) and went as much as 60 meters (195 feet) deep.

At this point, glaciologists are convinced that the crack will continue to expand in all three directions, until eventually it leads to a massive iceberg calving free of the PIG. The new island will cover an area of about 900 square kilometers (350 square miles).

The image to the left was acquired on November 13, 2011, by the NASA Terra satellite's Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument. The image only covers an area about 27-by-32 miles (44-by-52 kilometers) across.

The reason why these boundary glaciers surrounding Antarctica are so important is that sea-based ice does not contribute too much to rising global sea levels if it melts. Ground-based ices, on the other hand, can make a lot of difference, and must therefore be prevented from reaching the ocean at all costs.