SCIENCE OBSERVER
Pole Vaulting
David Schneider
The Amundsen-Scott South Pole Station made headlines in April when
the doctor for that remote science facility was taken seriously ill
in the middle of the dark, frigid Antarctic winter. Thankfully,
Canadian pilots successfully evacuated the stricken
physician—but he was not all that was ailing at the bottom of
the world. The station itself has been deteriorating for years,
prompting the National Science Foundation to begin this past year a
$153 million modernization, which should be complete by early 2006.
Built in the 1970s to replace an even older South Pole base (which
is now buried under nine meters of snow), the Amundsen-Scott Station
consists of a large geodesic dome and several smaller outbuildings.
The dome is half-buried in drifts and suffers from an unstable
foundation that threatens its integrity. Many other parts of the
infrastructure—from fuel distribution to waste
disposal—are also in dire need of refurbishment. But
construction at this remote site is no small task. All materials
have to be carried in by air from McMurdo Station on the coast using
special ski-equipped transport planes. And workers have to contend
with temperatures that average around –32 degrees Celsius over
the summer months.
The logistical difficulties and great expense prompt one to ask: Why
maintain a permanent science base at the South Pole at all? One
answer is that certain kinds of research can be done in no other
spot. In particular, the South Pole is said to offer an ideal
setting for astronomers, because the air is exceptionally cold, thin
and dry, making this locale the next best place to space for siting
a telescope. The South Pole also provides astrophysicists with a
remarkable laboratory to study high-energy neutrinos: AMANDA
(Antarctic Muon and Neutrino Detector Array) uses deeply buried
sensors at the South Pole to register the rare interactions between
these particles and the ice itself.
Such rationales for a base at the South Pole do not, however, hold
up very well under scrutiny. AMANDA could, for example, be installed
at any Antarctic site where the glacial ice is thick and free of
dust. Also, the air at the South Pole is, in fact, not so perfect
for astronomy, because it is colder at the surface than a few
hundred meters above. John Bally, an astronomer now at the
University of Colorado, Boulder, who was responsible for site
testing at the South Pole, points out that this temperature
inversion combined with the stiff winds there give rise to a
turbulent layer of air that blurs optical and infrared images. Bally
also notes that there is a perpetual ice fog at the South Pole in
winter and that the base is situated on the auroral circle, the
locus where charged particles in the upper atmosphere light up the
sky most intensely: "You would not go about picking
astronomical sites the way this was done."
Indeed, these problems make the South Pole appropriate for only a
limited number of astronomical observations, primarily those in the
submillimeter to millimeter regime. Shorter wavelengths (infrared
and optical) can be better studied in places like Mauna Kea in
Hawaii, which lacks a troublesome inversion layer. And longer
wavelengths (centimeter- and longer-wave radio frequencies) are so
little bothered by atmospheric absorption that siting the receiving
antennas at the ends of the earth is not necessary.
The submillimeter- to millimeter-scale observations are, however,
critical to the study of the cosmic microwave background radiation,
and they are useful too for examining molecular clouds in stellar
nurseries. So some astronomers are quite keen to set up their
instruments in Antarctica to take advantage of the thin, cold air.
Still, the South Pole is probably not the best place to conduct
these operations from a purely scientific perspective, because
higher elevations on the Antarctic Plateau offer even thinner and
colder air.
One such place is Dome C (located in the Australian sector, at
roughly 73 degrees South latitude), where French and Italian
scientists are now setting up a permanent base, called Concordia
Station. Peter Timbie, a physicist at the University of Wisconsin,
Madison, who plans to study the microwave background radiation from
Antarctica, says that although Dome C might be a slightly better
place to deploy his instrument, he plans to use South Pole Station
because he is reluctant to ask the NSF for money to do astronomy at
a French-Italian base: "My guess is that they would not be real
excited about that." Timbie notes that there is really very
little difference between the two sites for his research, but he
points out that the turbulent inversion layer may be absent at
Concordia, making it superior to the Pole for optical and infrared astronomy.
European and Australian astronomers are indeed quite interested in
the opportunities that Dome C affords. Still, U.S. participation
will probably not amount to much, because, as Bally notes, "the
U.S. has put all its eggs in South Pole." This strategy is hard
to defend on the basis of doing the best astronomy, the discipline
most often cited in official statements about the scientific
importance of Amundsen-Scott Station. Why then is keeping a base at
the South Pole worth the $153 million price tag?
The fundamental reason is that a permanent South Pole station is a
political necessity. The Under Secretary of State for Global Affairs
summed up the situation well in a 1997 letter to Norman Augustine,
then Chairman of the Board for Lockheed Martin Corporation and head
of an external panel to review the U.S. Antarctic program: "?
maintaining an active and influential United States presence in
Antarctica serves important strategic and foreign policy objectives.
This presence in Antarctica, anchored at the South Pole, gives us a
decisive voice in the Antarctic Treaty system, which is the basis
for the peace and stability of the area."
How the U.S. earned the privilege of siting one of its Antarctic
bases at the geographic pole in the first place is a charming piece
of history. American scientists first suggested the idea to the
Department of Defense in September of 1954 as part of their strategy
for the International Geophysical Year, a multi-nation research
effort focused on Antarctica. At the time, U.S. officials were
unwilling to commit to such a difficult undertaking. But just 10
months later at a planning conference in Paris, Russian scientists
announced that the Soviet government intended to erect a station at
the South Pole. The Americans in attendance were dumbstruck. Paul
Siple, a member of the U.S. delegation, recounts what followed in
his 1959 book 90° South:
Taking up the reins, Prof. G. Laclavere, the French
chairman of the conference, turned toward the Russians and shook his
head. "I'm sorry," he told them, "but we have already
accepted the offer of the United States to erect and man a South
Pole Station. We don't think there should be two stations there.
Siple further explains that the Russians subsequently accepted
Laclavère's suggestion that they build their station at the
geomagnetic south pole (a base called Vostok, which remains in place
today), making it impossible for the U.S. not to set up a
South Pole station.
Vostok, the consolation prize, is arguably a more valuable site for
scientific research in that by sheer luck it overlies a huge
subglacial lake, which investigators are eager to probe for signs of
life. And the glacial ice above this lake contains a longer record
of past climates than can be found at the South Pole. Vostok Station
also sits at a higher elevation, offering astronomers thinner and
colder air. Indeed Vostok boasts the lowest temperature ever
recorded on the surface of the earth: about –90 degrees C. So
in this sense at least, it was the Russians who won the cold
war.—David Schneider
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