|
After enduring months on the coldest, driest and windiest
continent on Earth, researchers closed out the inaugural
season on an unprecedented, multi-year effort to retrieve
the most detailed record of greenhouse gases in Earth's
atmosphere over the last 100,000 years.
Working as part of the National Science Foundation's
West Antarctic Ice Sheet Divide (WAIS Divide) Ice Core
Project, a team of scientists, engineers, technicians
and students from multiple U.S. institutions have recovered
a 580-meter (1,900-foot) ice core--the first section of
what is hoped to be a 3,465-meter (11,360-foot) column
of ice detailing 100,000 years of Earth's climate history,
including a precise year-by-year record of the last 40,000
years.
The dust, chemicals and air trapped in the two-mile-long
ice core will provide critical information for scientists
working to predict the extent to which human activity
will alter Earth's climate, according to the chief scientist
for the project, Kendrick Taylor of the Desert Research
Institute of the Nevada System of Higher Education. DRI,
along with the University of New Hampshire, operate the
Science Coordination Office for the WAIS Divide Project.
WAIS Divide, named for the high-elevation region that
is the boundary separating opposing flow directions on
the ice sheet, is the best spot on the planet to recover
ancient ice containing trapped air bubbles--samples of
the Earth's atmosphere from the present to as far back
as 100,000 years ago.
While other ice cores have been used to develop longer
records of Earth's atmosphere, the record from WAIS Divide
will allow a more detailed study of the interaction of
previous increases in greenhouse gases and climate change.
This information will improve computer models that are
used to predict how the current, unprecedented high levels
of greenhouse gases in the atmosphere caused by human
activity will influence future climate.
The WAIS Divide core is also the Southern Hemisphere
equivalent of a series of ice cores drilled in Greenland
beginning in 1989, and will provide the best opportunity
for scientists to determine if global-scale climate changes
that occurred before human activity started to influence
climate were initiated in the Arctic, the tropics or Antarctica.
The new core will also allow investigations of biological
material in deep ice, which will yield information about
biogeochemical processes that control and are controlled
by climate, as well as lead to fundamental insights about
life on Earth.
Says Taylor, "We are very excited to work with ancient
ice that fell as snow as long as 100,000 years ago. We
read the ice like other people might read a stack of old
weather reports."
The WAIS project took more than 15 years of planning
and preparation, including extensive airborne reconnaissance
and ground-based geophysical research, to pinpoint the
one (less than a square mile) space on the 932,000-square-kilometer
(360,000-square-mile) ice sheet that scientists believe
will provide the clearest climate record for the last
100,000 years.
With only some 40 days a year when the weather is warm
enough for drilling--yesterday's temperature was a balmy
-15 degrees Celsius (5 degrees Fahrenheit)--it is expected
to take until January 2010 to complete the fieldwork.
For the project, Ice Coring and Drilling Services of
the University of Wisconsin-Madison built and is operating
a state-of-the-art, deep ice-coring drill, which is more
like a piece of scientific equipment than a conventional
rock drill used in petroleum exploration. The U.S. Geological
Survey National Ice Core Laboratory in Denver designed
the core handling system. Raytheon Polar Services Corporation
provides the logistical support. The NSF Office of Polar
Programs-U.S. Antarctic Program funds the project. The
core will be archived at the National Ice Core Laboratory,
which is run by the USGS with funding from NSF.
-
NSF
-
|
