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NSF PR 97-68 - November 5, 1997
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1997-98 Antarctic Research Season Underway
A new research season is underway in Antarctica, encompassing
175 research projects supported by the National Science
Foundation (NSF), the federal agency that funds and
manages the U.S. Antarctic Program.
Studies are based out of three research stations --
McMurdo, Amundsen-Scott South Pole and Palmer -- as
well as on two research vessels, the Nathaniel B.
Palmer and a new vessel, the Lawrence M. Gould.
Research covers earth sciences, glaciology, biology,
medicine, oceanography, meteorology, aeronomy and
astrophysics. Highlights of the current season include:
- Ice Drilling at Siple Dome: Drillers will
extract a 1,000-meter core from West Antarctica's
Siple Dome, a mound of ice between two fast-flowing
ice streams. The ultimate goal is to study the
annual layers of ice to improve predictions of
climate change. The rivers of ice drain the West
Antarctic ice sheet and are critical to its stability.
Such current changes in the ice sheet could be
on-going responses to the end of the last ice
age, pointing to rapid melting, or they may be
merely local effects. In any case, West Antarctica's
ice, resting on ocean crust in a basin below sea
level, may be most vulnerable to melting and raising
global sea level. Siple Dome will also be drilled
to understand dynamics of ice flow there, which
is mainly in the vertical direction. Scientists
will drop instruments into water-filled holes
to measure vertical deformation of the ice, in
the first such direct measurements of vertical
velocity at a deep ice-core site.
- Cape Roberts Project Probes Ross Sea Floor:
Geologists have extracted a core from the floor
of the Ross Sea, drilling from a rig on sea ice
off Cape Roberts, about 75 miles north of McMurdo
Station. Drilled cores will span the period 30-100
million years ago. Like a history book missing
a chapter, Antarctica has no exposed rocks of
this age. The Ross Sea rocks can be drilled with
relative ease because older beds are tilted up
toward the sea floor surface. During the interval
the rocks were deposited, the mega-continent of
Gondwanaland underwent its final rupture as New
Zealand and Australia pulled northward away from
Antarctica. The cores should also shed light on
the stability of Antarctica's ice sheets during
this time. During the three-year project, a joint
venture between the United States, New Zealand,
the United Kingdom, Australia, Germany and Italy,
the cores will be analyzed at McMurdo Station
as they emerge, with a preliminary report available
at the field season's end.
- Dosvedanya to Drilling at Vostok: In a
joint U.S.-Russian-French venture, scientists
will complete drilling of the world's deepest
ice core this season at Russia's Vostok Station.
Drilling last stopped in February, 1997 at a depth
of 3,523 meters. Covering over 400,000 years of
snowfall, this core spans four glacial-interglacial
cycles, furnishing an archive of information on
past climate history. The drillers will plumb
about 175 more meters of ice, stopping 50 meters
above Lake Vostok so as not to contaminate the
huge lake sealed beneath the ice sheet.
- Ultraviolet Revelations: When more than
half of Antarctica's stratospheric ozone disappears
each spring, the sun's ultraviolet-B radiation
can penetrate to the Earth's surface and into
the sea. Scientists will study how UV-B affects
the embryos and larvae of three key invertebrates
living in shallow waters off the U.S. Palmer Station
near the Antarctic Peninsula. Another project
at Palmer will study the photochemistry of seawater
surrounding cells in organisms bombarded by increased
UV-B. Such chemistry can influence damage to the
cell surface. Still other work will quantify how
UV light affects plankton, the base of the ocean
food chain.
- Sea Ice -- From Ship to Space: The growth
and shrinkage of the sea ice around Antarctica
may be the greatest seasonal event on Earth. Scientists
aboard the Nathaniel B. Palmer, NSF's icebreaking
research ship, will compare ice and snow on the
surface with how they appear in satellite images.
Actual measurements of ice on the surface help
to validate computer models of climate by making
simulations of sea ice more accurate.
- Turbulent Mixing: Very cold, saline water,
formed in the depths of the southernmost Weddell
Sea, feeds dense "bottom water" that spreads throughout
the world ocean. U.S. scientists on a British
Antarctic Survey research vessel will study the
open water at the face of the Filchner-Ronne Ice
Shelf, focusing on how the water emerging from
beneath the shelf mixes with other water masses.
- Tracking Neutrinos and the Big Bang from the
South Pole: The Antarctic Muon and Neutrino
Detector Array (AMANDA) is a different sort of
telescope, buried in the ice cap at the South
Pole to look downward into the earth for the telltale
traces of neutrinos. Leading the nascent field
of neutrino astronomy, AMANDA studies the ghostly
subatomic particles emitted from such sources
in space as supernovae remnants, pulsars, neutron
stars, or active galactic nucleii. The neutrinos
pass right through the North Pole, on through
the earth, and stream into AMANDA's detectors.
Scientists will augment the current array this
season by adding three new detector strings to
the 14 already in place. New at South Pole this
season will be Viper -- a two-meter diameter telescope
designed to look at radiation left over from the
Big Bang, on a smaller scale than has been done
from the Pole before (initially, with an angular
scale of one-half degree at a six-millimeter wavelength;
in the future, on a finer scale).
- Astronomy by Balloon: Antarctica's summer
weather provides a stable ride for instruments
hung beneath a balloon, which floats around Antarctica
at a steady height above most of the atmosphere,
providing a cheaper way to get scientific experiments
into space. This year, a spectrometer will sail
for 10 days around the continent, tracking gamma
rays emitted by neutron stars, black holes, the
center of the galaxy, and other features.
- "Icebreaker" to Herald New South Pole Station:
In early December, NSF will formally break ground
-- or break the ice -- for renovations at the
South Pole, including construction of a new garage
and shop, fuel storage system, and power plant.
This season, the site will be prepared and a new
arch will be erected to house the garage and shop.
Also, a new Atmospheric Research Observatory will
be dedicated in January at the South Pole, replacing
the overcrowded and aging Clean Air Facility.
The ARO will offer twice the space of its predecessor
for research on climate, ozone, ultraviolet light,
and other atmospheric studies.
Editors: For summaries of all field projects
of the U.S. Antarctic Program during the 1997-98 season,
request publication NSF 97-167 from pubs@nsf.gov
or call 301-947-2722.
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