Antarctica is the world’s southernmost continent and is located almost completely south of the Antarctic Circle. It is also the coldest, driest, and windiest continent, and approximately 98% of Antarctica is covered by ice that has an average thickness of nearly 2 km. Despite being largely covered in ice, Antarctica contains numerous lakes and rivers. Many of these lakes are subglacial. The largest of the 400 known subglacial lakes in Antarctica is Lake Vostok, which is located beneath Vostok Station, a Russian research station in Prince Elizabeth Land, Antarctica. Lake Vostok is a freshwater lake situated approximately 4,000 m beneath surface of the ice sheet, which means it is approximately 500 m below sea level.
Lake Vostok was most likely sealed off by a thick ice sheet approximately 15 million years ago. Researchers initially believed the same water had been in the lake since its formation. However, researchers Robin E. Bell and Michael Studinger from Columbia University’s Lamont-Doherty Earth Observatory later proved that the lake’s water was continually freezing and getting carried away by moving ice sheets, and then replaced by water created through the cumulative pressure of the ice sheets. As a result, the entire lake water is replaced approximately every 13,300 years.
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