The Prince Albert Mountains rise up from Antarctica’s Scott Coast on the western shores of the Ross Sea. Like the Rocky Mountains, the Andes, the Himalayas, or the Alps, the Prince Albert Mountains are being shaped by mountain glaciers. Among them is the David Glacier on the 1,831-meter-high Mt. Joyce. As ice piles on the glacier, it slides under its own weight to the ocean. The ice doesn’t break up when it reaches the ocean; rather, it floats, forming a long tongue of ice. The floating end of the David Glacier is the Drygalski Ice Tongue.
These images, acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua and Terra satellites, show the ice tongue emerging from the Scott Coast and floating on the Ross Sea with its end pointing towards the upper right corner.
This floating spit of ice was recently menaced by the B-15A iceberg, a 120-kilometer-long giant that had been drifting on a collision course with the ice tongue before becoming grounded. The iceberg is visible just below the Drygalski Ice Tongue, mere kilometers away from its end. NASA scientists speculated that if a collision were to occur, the force could break off a section of the ice tongue. No collision was necessary, however; on February 21, 2005, Drygalski calved an iceberg on its own. The five-by-ten-kilometer iceberg was floating away from the ice tongue on February 25, when the second image was acquired. The event is a normal part of the evolution of the ice tongue—pieces regularly break from the tongue as the glacier pushes more ice out over the sea.