Antarctica is the southernmost continent on the planet, covering 14 million square kilometers, almost twice the size of Australia, and covered by ice across 98% of its surface, reaching up to 4,776 meters in thickness in some areas. It is divided into West Antarctica, with the Antarctic Peninsula and the Ross Ice Shelf, and the larger and colder East Antarctica, where the lowest temperatures on Earth have been recorded, reaching minus 89.2 degrees Celsius at Vostok Station. The 1959 Antarctic Treaty freezes the territorial claims of seven countries but establishes areas of scientific influence, and the Antarctic Peninsula is the most accessible region and the one with the greatest risk of invasive species becoming established. In this Risk, the peninsula is the key territory because of its less extreme climate and connections with South America, the Ross Ice Shelf is a gateway to the South Pacific, and controlling the coastal research stations gives you reach over circumpolar maritime routes. The frozen interior is an almost impassable zone requiring a major deployment to consolidate.