The earth's fifth largest continent, centered asymmetrically around the South Pole. Ninety-eight percent of this land mass, which covers approximately 5.4 million mi² (13.8 million km²), is covered by snow and ice sheets to an average depth of 1.25 mi (2 km). This continent receives very little precipitation, less than 5 in (12 cm) annually, and the world's coldest temperature was recorded here, at -128°F (-89°C). Exposed shorelines and inland mountain tops support life only in the form of lichens, two species of flowering plants, and several insect species. In sharp contrast, the ocean surrounding the Antarctic continent is one of the world's richest marine habitats. Cold water rich in oxygen and nutrients supports teeming populations of phytoplankton and shrimp-like Antarctica krill, the food source for the region's legendary numbers of whales, seals, penguins, and fish. During the nineteenth and early twentieth century, whalers and sealers severely depleted Antarctica's marine mammal populations...