The ice at Vostok is almost 12,000 feet thick, and the lake sits almost two miles below the surface. Dubbed Lake Vostok, the sixth largest freshwater body in the world by volume, it is roughly the size of Lake Ontario. We now know that the lake contains several islands and is one of four hundred freshwater lakes under the Antarctic Ice Sheet. Some of them, such as Lake Vostok, may have been separated from the world above for over 15 million years.
