The continent of Antarctica is almost completely covered by a
thick blanket of ice, punctuated only by steep mountain peaks
and a handful of dry valleys. Antarctica is also ringed by a permanent
ice shelf, and that is surrounded by seasonal sea ice.
The image above, acquired by the Moderate-resolution Imaging
Spectroradiometer (MODIS) on September 26, 2001, shows many of the
types of ice found in Antarctica. At the bottom of the image is the ice
of the continental glacier, which is up to 4,000 meters thick in the
interior. These thick glaciers are held in place by coastal
mountain ranges. Some ice does flow through the mountains, spilling onto
the relatively flat land of the Princess Astrid Coast. Cold air also spills
over the mountains, creating very strong and persistent katabatic
winds. These scour the snow off the tops of the glaciers, leaving pale blue
patches of bare ice. Above the coastline is the ice shelf, which is much smoother. There, glacial ice actually floats on the sea surface. Beyond that is the chaotic surface
of the sea ice, which has been solidifying all winter long.
Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC