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Science Frontiers ONLINE No. 107: Sep-Oct 1996 |
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Antarctica's Lake Vostok Revisited
Based upon a Japanese account, we reported the discovery of Lake Vostok in SF#102 almost a year ago. Some details are finally appearing in Western science publications. We can now offer a good cross section of the lake, plus some thoughts about potential ecosystems existing deep under the lake's ice.
Although Lake Vostok lies under some 4 kilometers of ice, it remains liquid as geothermal heat seeps up through its floor. Surprisingly, the thick ice cover does not preclude all contact with the surface above. The covering ice sheet moves slowly across the lake and, as it does so, its bottom melts a bit, releasing frozen-in oxygen as well as life forms -- still-living microorganisms and dead creatures that fell onto the Antarctic ice thousands of years ago. Thus, there is a perpetual source of food and new life.
Cores drilled from the ice sheet capping Lake Vostok have brought up a great diversity of live microbes that have survived despite the low temperatures and passage of time. A living unicellular alga was found 2,375 meters down in ice about 110,000 years old. Spore-forming bacteria brought up from 2,395 meters are about 200,000 years old and still alive! Although science has proclaimed that Lake Vostok biology must consist entirely of microorganisms, no one really knows what is down there.
Another fascinating fact is that some 70 other subglacial bodies of fresh water have been found under the central Antarctic ice sheet. Lake Vostok is only part of a "vast hydrological system."
(Kapitsa, A.P.; "A Large Deep Freshwater Lake beneath the Ice of Central East Antarctica," Nature, 381:684, 1996. Monastersky, R.; "Giant Lake Hides beneath Antarctica's Ice," Science News, 149:407, 1996)
Comment. Antarctica's "vast hydrological system" could be linked to a global crevicular system of fluid-filled, lifesustaining cracks, fissures, and porous rocks.
