From: LARRY KLAES (ljk4@msn.com)
Date: Tue Jul 02 2002 - 23:00:03 PDT
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From: baalke@jpl.nasa.gov
Sent: Monday, July 01, 2002 6:29 PM
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Subject: UC Berkeley Scientist Urges Drilling Into Frozen Lake Under Ice Near South Pole
http://www.berkeley.edu/news/media/releases/2002/06/28_ice.html
UC Berkeley scientist urges drilling into frozen lake under ice near South
Pole as prelude to drilling into subglacial lakes in Antarctica and into
Mars polar caps
By Robert Sanders, Media Relations
UC Berkeley Press Release
June 28, 2002
Berkeley - Measurements of the ice temperature far below the South Pole
suggest that a so-called "lake" discovered at the base of the ice is most
likely permafrost - a frozen mixture of dirt and ice - because the
temperature is too low for liquid water.
Far from being a disappointment, says a University of California, Berkeley
physicist, the permafrost subglacial lake may be ideal for developing and
testing sterile drilling techniques needed before scientists attempt to
punch through the ice into pristine liquid lakes elsewhere in Antarctica in
search of exotic microbes.
Techniques that avoid contaminating a drill site with microbes also would
prove useful for future drilling into Mars' polar caps in search of life.
"This would be an excellent place to develop a sterile drill," said P.
Buford Price, professor of physics at UC Berkeley. "Then, if we find that
we've inadvertently contaminated the permafrost lake, we can be confident
that the contamination is confined to only a small area."
Drilling into a frozen lake 2.8 kilometers below South Pole Station would
have scientific interest in its own right, he said.
"We are likely to find interesting microbial life in the permafrost, in
addition to learning how to drill in a sterile way," he said.
Price and colleagues in the United States and Russia made the recommendation
in a paper that appeared in the June 11 issue of the Proceedings of the
National Academy of Sciences. In their paper, the team reported data on
temperature versus depth down to 2.3 kilometers beneath South Pole Station,
based on temperature sensors implanted as part of the Antarctic Muon and
Neutrino Detector Array (AMANDA) observatory.
Price, a cosmic ray physicist, is one of more than 100 collaborators in the
AMANDA project, a National Science Foundation-funded array of detectors
imbedded in deep ice at the South Pole and primed to look for high-energy
neutrinos originating in exotic objects outside our solar system, such as
black holes or the active centers of distant galaxies. AMANDA will become
part of a larger, kilometer-scale neutrino observatory named IceCube, for
which funding by NSF began earlier this year.
Based on measurements down to 2.3 kilometers, the team estimated the
temperature at the bottom of the ice, 2.8 kilometers below the surface. This
temperature - 9 degrees below zero Celsius (about 15 degrees Fahrenheit) -
is 7 degrees colder than the temperature at which ice melts under the
pressure of nearly 3 kilometers of ice.
Several years ago, radar images of the ice around the South Pole showed
evidence of a subglacial lake about 10 kilometers from the pole. Price said
that the temperature there should be about the same as the temperature at
the AMANDA site, meaning that the under-ice lake would likely be a frozen
mixture of ice and sediment in order to explain the flat terrain indicated
by radar images. The permafrost, similar to that found in Arctic regions of
North America and Europe, may be 10 or 20 million years old, dating from
before the Antarctic continent was covered by a sheet of ice.
Since any contamination introduced by drilling into the permafrost would not
travel far, the site would make a good place to test such techniques in
preparation for drilling into Lake Vostok, a huge, Lake Ontario-sized
subglacial sea that has intrigued scientists since it was detected four
kilometers below the ice in 1996.
Proposals to drill into Lake Vostok have met with opposition because of the
danger of contamination. In addition, many of the nearly 100 under-ice seas
discovered to date may be interconnected, so contaminating one could
contaminate them all. An international committee is discussing the issue,
which may delay drilling for a decade.
Drilling first at the site near the South Pole also would be more
convenient, because there currently are no permanent facilities near
Antarctica's subglacial lakes comparable to South Pole Station.
As part of the AMANDA and IceCube projects, temperature gauges were
installed in bore holes that had been drilled with hot water down to 2,345
meters, nearly to the base of the ice at 2,810 meters at the South Pole. The
gauges provided a detailed profile of temperature under the surface and also
allowed Price and his colleagues to predict the temperature at the base of
the ice: -9ºC
Price is primarily interested in the kinds of exotic microbes that might
live inside solid ice, either as dormant spores or at a low level of
activity. He said that life has been found wherever people have looked, from
deep in the Earth's crust to high-altitude clouds, and he thinks they also
reside deep inside glacial ice. In fact, he will present a poster on life in
solid ice at the Bioastronomy 2002 meeting in Australia during the week of
July 8.
Such creatures would not live in ice crystals, but in interconnected liquid
veins at the boundaries where ice crystals meet.
"Even at temperatures far below the freezing point, there is always some
liquid," he said. "As water freezes, soluble salts and acids are excluded
from the interiors of the freezing crystals, creating a network of thin
liquid veins rich in nutrients for energy and elements such as carbon
necessary for building more microbes. Bacteria are small enough to fit and
move inside the veins. Why wouldn't bacteria take advantage of that? Well,
they probably do."
He and UC Berkeley colleagues have developed instruments that they have
lowered into boreholes in Greenland and Antarctic ice to search for
microbial life. The devices flash ultraviolet light, and detectors record
any telltale fluorescence from bacteria. Such fluorescence is faint,
however, and the team is still perfecting the instrument.
In a second approach, Price and his colleagues have built at UC Berkeley a
refrigerated box in which they can investigate sections of ice cores from
Antarctica and Greenland in search of exotic, deep-ice bacteria new to
science. With a fluorescence microscope mounted inside the cold box, they
can search for the faint light emitted by fluorescing bacteria.
"With the refrigerated microscope, we can catch any microbes trapped in
liquid veins in their icy habitats," Price said. "This greatly reduces the
possibility of contamination. If we just looked in melted ice, we wouldn't
know where the bacteria had come from."
Drilling in Antarctic ice, including to within about 100 meters of Lake
Vostok, has turned up some bacteria, according to Russian scientists, but
all were known before. Bacteria also have been found in ocean ice. Price and
other scientists hope to discover new species in solid ice, analogous to the
novel thermophiles found in hot seafloor vents living at temperatures above
the sea-level boiling point of water (100ºC or 212ºF).
"If microbes can exist in glacial ice on Earth, they can also exist in
Martian permafrost and in certain regions of Jupiter's ice-covered moons,"
he said.
Price's colleagues on the recent PNAS paper are Oleg V. Nagornov of the
Moscow Engineering Physics Institute; Ryan Bay, Dmitry Chirkin, Predrag
Miocinovic and Kurt Woschnagg of UC Berkeley; Yudong He of Rosetta
Inpharmatics in Kirkland, Wash.; Austin Richards of Indigo Systems
Corporation in Santa Barbara, Calif.; Bruce Koci of the Space Sciences and
Engineering Laboratory at the University of Wisconsin, Madison; and Victor
Zagorodnov of the Byrd Polar Research Center at Ohio State University in
Columbus.
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