Antarctica's Ice Sheets and Bedrock

Antarctica covers roughly 14 million square kilometers of land, about 98 percent of it buried under ice, holding a total ice volume of approximately 26.5 million cubic kilometers according to the Bedmap2 dataset compiled by Fretwell et al. (2013) — a volume equivalent to some 70 percent of the world's fresh water. The continent is conventionally divided into two ice sheets separated by the Transantarctic Mountains, a range that runs for more than 3,500 kilometers and rises to 4,528 meters at Mount Kirkpatrick. The East Antarctic Ice Sheet, the larger and older of the two, rests mostly on bedrock above sea level and is comparatively stable; the West Antarctic Ice Sheet, smaller and thinner, is grounded largely on bedrock that lies below sea level, a configuration known as a marine ice sheet that makes it inherently more vulnerable to rapid retreat. The continent's single highest point, Vinson Massif in the Sentinel Range of the Ellsworth Mountains, reaches 4,892 meters and lies within West Antarctica.