Antarctica is the Earth's southernmost continent and contains the geographic South Pole. It is a unique landmass because it has no permanent residents and is not owned by any single country; instead, it is governed by the Antarctic Treaty System, which designates it as a scientific preserve. About 98% of Antarctica is covered by ice that averages at least 1.9 kilometers in thickness. It is the coldest, driest, and windiest continent, and has the highest average elevation of all the continents. Despite the harsh conditions, it is home to various species of penguins, seals, and krill. Antarctica holds about 70% of the world's fresh water and 90% of the world's ice. If all of its ice were to melt, global sea levels would rise by approximately 60 meters. There are no cities or capitals, but several countries maintain year-round research stations, such as McMurdo Station (USA) and Vostok Station (Russia).