Using satellite images and software, researchers
at the Ohio State University are mapping
land routes across the Antarctic that could make it safer and easier to
transport equipment and supplies to the South Pole.

Led by Carolyn
Merry, professor of civil
engineering at Ohio State, the researchers have mapped potential routes
across a stretch of the Ross Ice Shelf, one of the giant ice sheets that
extends outward from the frozen continent. Merry’s group reported the
work in a recent issue of the journal Cold
Regions Science and Technology.

The routes start at the McMurdo
Station, the main entryway to Antarctica – some 850 miles from the
South Pole –
and head towards the Leverett Glacier in the Transantarctic
mountains. Overland travel across the stretch of the ice shelf between
McMurdo and the glacier is fraught with dangers because of deep crevasses
that lie hidden under snow. Past this corridor, beyond the ice shelf to
the South Pole, lies a decidedly safer terrain.

In 1991, a tractor traveling across the ice shelf — a thick
layer of ice floating upon the Ross Sea – fell into a crevasse, bringing
home the risks associated with surface transport from McMurdo to the interior
of Antarctica. That’s one of the reasons why supplies to the U.S. station
at the South Pole are transported entirely by aircraft.

But overland travel could be more economical and convenient than air
transport. "There is only a limited amount of materials that you
can put on a C-130," Merry said, referring to the type of aircraft
used for transporting goods. "With tractor trailers, you could transport
a large volume of supplies in a single trip."

Merry and her colleagues analyzed satellite images of the area to identify
potential travel routes through the corridor. Using software, the researchers
enhanced the images and were able to locate crevasses in the ice shelf.
The crevasses – deep cracks in the ice layer – showed up in the images
as shadow lines on a white sheet.

"These crevasses are very hard to see from the ground and even from
a low-flying airplane because a lot of them are bridged over by snow that
drifts into them," Merry said.

Based on the images, the researchers came up with safe routes through
the corridor. The next step, Merry said, would be to confirm the safety
of the suggested routes through surveys on the ground using radar technology.
"Having a preliminary route to work with would save time and money
on follow-up ground surveys," Merry said.

Merry and her colleagues, including the late Ian
M. Whillans, professor of geological sciences at Ohio State and lead
author of the study, used the satellite images for another, more fundamental
purpose – to measure the rate of movement of ice sheets in the region.
These ice sheets slide northward every year, slowly melting into the ocean.

Comparing images of the Ross Ice Shelf taken in 1989 and in 1994, the
researchers found that most of the ice streams flowing along the shelf
were moving at about 200 meters per year. The observation confirms previous
field measurements that used less reliable techniques.

"What we have learned is there are some parts of the ice shelf that
are moving faster than other parts," Merry said. "Although most
of our observations confirm previous findings, we have added additional
velocity measurements in the site that we never had before."

The research was funded by a grant from the National
Science Foundation.

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Contact: Carolyn Merry, (614) 292-6889, merry.1@osu.edu
Written by: Yudhijit Bhattacharjee, (614) 292-8456, bhattacharjee.5@osu.edu