Today, only geological formations, coal beds, and fossils remain as clues to Antarctica's temperate past. Surrounding Antarctica are the southern parts of the Pacific, the Atlantic, and the Indian Oceans. Sea ice to ten feet thick forms outward from the coast. In summer the sea ice occupies less than two million square miles. But in winter it is a wide belt of eight million square miles, an area that exceeds that of the continent itself and which is impenetrable even by icebreakers.
Life has a tenuous hold on Antarctica.
The ice-covered interior supports no life at all. Bacteria and yeasts have been recorded on exposed rocks. Lichens and mosses occur in a few ice-free areas, and two flowering plants grow along the Antarctic Peninsula. Native land animals are limited to seventy-six species of insects. The cold ocean waters are rich in nutrients and produce an immense amount of phytoplankton, which supports large populations of krill, fishes, birds, seals, and other animals.