Engineers from the Ice Coring and Drilling Services at the
University of Wisconsin returned home last week after an expedition to retrieve
information on climatic changes in West Antarctica.
The National Science Foundation?s Ice Core Project aimed to
retrieve columns of ice that contain gasses and biological matter from the past
100,000 years. The ice was extracted from the West Antarctic Ice Sheet Divide
using a deep ice sheet coring drill.
?The drill was built in a warehouse just off campus,? said
Jennifer O?Leary, associate university relations specialist for the Space
Science and Engineering Center.
The coring drill is a special hollow drill that cuts holes
122 millimeters in diameter and three meters in length. It is designed to
collect ice core from as deep as 3,800 meters.
?The drill is like a long cookie cutter,? said Charles
Bentley, principal investigator for the DISC drill project. ?It has a long tube
with a cutter on the bottom. It cuts out a whole column of ice, and after the
column is about 3 meters into the tube, it comes back up, and the ice is pushed
out of the tube.?
The ice core in the WAIS Divide will give researchers
unprecedented insight into climactic changes and history in order to provide a
detailed account of the climate in the past 40,000 years.
The first 580-meter core that was extracted from the almost
2 1/2-mile deep WAIS Divide will be sent to the Ice Core Lab in Denver, Col.,
where researchers and scientists will analyze the gasses, dust particles and
biological matter found in the tiny air bubbles trapped in the ice.
?The [gasses trapped in the] ice core will give information
primarily about past climate,? Bentley said. ?The more we know about the
climate in the past, the more we will know about [the climate of] the future.?
The design team at UW began building the drilling machine
several years ago, said Alex Shturmakov, project manager of the ICDS drill
project.
?We first tested the drill in Greenland,? said Shturmakov.
?We drilled over 180 meters of ice. It was very successful.?
The team brought the drill back to Madison to recalibrate a
few parts and then sent it to Antarctica.
This particular part of Antarctica ? the west region ? was
chosen for several reasons, Charles Bentley said. The WAIS Divide is a very
thick ice core, and the area has a high level of snow accumulation.
?That means you get a higher resolution record [in the
data], and we should be able to count back the annual layers in the ice,?
Bentley said.
However, the ice that the team will be drilling next year is
very different from that of this year.
?Next year we will be drilling brittle ice, which is likely
to shatter if we ship it,? Bentley said. ?The ice will sit at the site for a
whole year to settle and then will be shipped to Denver.?
Shturmakov said that this is the first of three drillings
that the team will do. They plan to take the core in three sections, drilling
the last two sections in the next two years.
