Lake Vostok
May 2002
Background
Antarctica is home to more than 70 lakes that lie thousands
of meters under the surface of the continental ice
sheet, including one under the South Pole itself.
Lake Vostok, beneath Russia's Vostok Station, is one
of the largest of these subglacial lakes, comparable
in size and depth to Lake Ontario, one of the North
American Great Lakes. There is some evidence that
Vostok's waters may contain microbial life. Exploration
of the lake to confirm that life exists will be an
international effort and will require the development
of ultra-clean technologies to prevent contaminating
the waters.
The National Science Foundation, as manager of the
U.S. Antarctic Program, coordinates nearly all U.S.
research in Antarctica and would lead U.S. participation
in any international effort to explore the lake. NSF's
Office of Polar Programs has established a steering
committee to study the possible scientific exploration
of Antarctic subglacial lakes. See: http://www.nsf.gov/od/opp/antarct/subglclk.htm
Research challenges
Vostok Station is located in one of the world's most
inaccessible places, near the South Geomagnetic Pole,
at the center of the East Antarctic Ice Sheet. The
station is 3.5 kilometers (11,484 feet) above sea
level. The coldest temperature ever recorded on Earth,
-89.2 degree Celsius (-128.6 degrees Fahrenheit),
was measured at Vostok Station on July 21, 1983.
Lake Vostok's physical characteristics have led scientists
to argue that it might serve as an earthbound analog
for Europa, a moon of Jupiter. Confirming that life
can survive in Lake Vostok might strengthen the argument
for the presence of life on Europa.
Russian and British scientists confirmed the lake's
existence in 1996 by integrating a variety of data,
including airborne ice-penetrating radar observations
and spaceborne radar altimetry.
Researchers working at Vostok Station have already
contributed greatly to climatology by producing one
of the world's longest ice cores in 1998. A joint
Russian, French and U.S, team drilled and analyzed
the core, which is 3,623 meters (11,886 feet) long.
The core contains layers of ice deposited over millennia,
representing a record of Earth's climate stretching
back more than 420,000 years. Drilling of the core
was deliberately halted roughly 150 meters (492 feet)
above the suspected boundary where the ice sheet and
the liquid waters of the lake are thought to meet
to prevent contamination of the lake.
It is from samples of this ice core, specifically from
ice that is thought to have formed from lake water
freezing onto the base of the ice sheet, that NSF-funded
scientists believe they have found evidence that the
lake water supports life. Their research was published
in Science in 1999.
For more information, see: http://www.nsf.gov/od/lpa/news/press/99/pr9972.htm
More recently, NSF-funded researchers from the Lamont-Doherty
Earth Observatory at Columbia University, using data
gathered by the University of Texas Institute for
Geophysics, published a paper in Nature suggesting
that the hydrodynamics of Lake Vostok may make it
possible to search for evidence of life in the layers
of ice that accumulate on the lake's eastern shore.
Scientists say such a possibility would provide another
avenue for exploring the lake's potential as a harbor
for microscopic life, in addition to exploring the
lake itself. For more information, see: http://www.nsf.gov/od/lpa/news/02/pr0219.htm
International consensus building
Discussions at an NSF workshop for U.S. researchers
held in 1998, a subsequent international meeting held
in Cambridge, England in 1999, as well as other international
meetings about subglacial lakes, have formed the basis
for a developing scientific consensus on whether,
and how, to proceed with exploring the lake's waters.
To read a report from the 1998 NSF workshop "Lake Vostok:
A Curiosity or a Focus for Interdisciplinary Study?"
see: http://www.ldeo.columbia.edu/vostok/
The Scientific Committee on Antarctic Research (SCAR)
hosts a Web site on subglacial lake exploration with
links to several reports from various international
workshops. See: http://salegos-scar.montana.edu/
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