Antarctica's Lake Vostok
Specialists in disciplines ranging from glaciology to engineering are preparing to explore the world's largest subglacial lake
At the base of the Antarctic ice sheet, some 4 kilometers below the Russian Vostok research station, lies an accumulation of water about the size of Lake Ontario. This remote body, named Lake Vostok, is by far the largest subglacial lake in the world. It persists despite surface temperatures that regularly hover around –60 degrees Celsius, because the bottom of the ice at this locale absorbs enough heat from the interior of the earth to keep the lake from freezing.
Scientists estimate that the ice sheet above Lake Vostok has been in place for at least several million years and possibly as long as 15 million years. The origins of the lake may therefore date back across geological time to the Miocene epoch, when the Mediterranean was sometimes a desert and horses were about the size of collie dogs.
An ancient, ice-bound lake intrigues earth scientists for obvious reasons. Biologists, too, are quite interested, because they expect that the lake harbors microorganisms that may have entered at the time of formation and have since adapted to the extreme conditions reigning there—that is, to exceedingly low nutrient and energy levels. Because Lake Vostok has been completely isolated from the rest of the planet for at least several hundred thousand and perhaps several million years, the organisms within it must have undergone an independent course of evolution over this interval, perhaps resulting in life forms that are unique to this strange place.
So it is small wonder that plans are afoot to explore this and other subglacial lakes in Antarctica. Before such efforts can be mounted, however, glaciologists need to know more about the ice above the lake and about the rocks and sediment below it. To understand how my colleagues and I hope to gather this new information, it is useful to review how existing knowledge about the lake was obtained.