of Water Detected, Beneath Surface of Antarctica .
Researchers published their evidence of a vast system..
Antarctica is Earth's southernmost continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean, it contains the geographic South Pole. Antarctica is the fifth-largest continent, being nearly twice the size of Australia, and has an area of 14,200,000 km2 (5,500,000 sq mi). Most of Antarctica is covered by ice, with an average thickness of 1.9 km (1.2 mi).