Editor’s note: Marine geophysicist Robin Bell is leading an expedition to Antarctica to explore a mysterious mountain range beneath the ice sheet. Following is the tenth of her updates on the effort as part of ScientificAmerican.com‘s in-depth report on the "Future of the Poles."
McMURDO STATION, ANTARCTICA– Just 24 hours ago, all the teams were pinned down on Antarctic coasts by weather, equipment and bureaucracy. Tonight several groups are moving toward the center of the ice sheet. Yesterday morning I almost overslept and would have missed my chance see two members of the British team as they headed off to the South Pole. I dashed up to the McMurdo departure building to find Carl and Doug already sitting in the van that would drive them to the aircraft. They had their huge bags of ECW (Extreme Cold Weather) gear with them, but otherwise the van resembled a van from anywhere in front of a Holiday Inn.
Yet with oversized tires designed for snow and ice travel, the van does not travel on paved roads. Like an all-terrain vehicle (ATV), it travels off the volcano, across the growing slushy pond, onto the 300-foot thick floating ice and up to a New York National Guard C-130, a cargo plane fitted with skis. The aircraft will head south until south becomes north again, landing at the South Pole on the 9,184 foot- (2,800 meter-) thick East Antarctic ice sheet, arriving just in time for lunch. Later in the day the bright red Twin Otter that is stuffed with instruments, will follow. The trip that takes just under three hours on the C-130 from Schenetady, will take almost seven hours in the smaller, slower Twin Otter. This is in part because the Twin Otter trip will include a stop at a fuel cache on the edge of Moody Glacier to refill the aircraft tanks. Self-service is the norm at these remote Antarctic “gas stations.” Polar self-service requires shoveling snow off the 55- gallon drums of fuel buried in drifts.
The Otter and crew arrived in time for a late dinner. The British team will stay at South Pole adjusting to the altitude before flying the first survey lines to the north over the ice sheet this weekend. These lines will be the first survey data we collect over the East Antarctic ice sheet. The East Antarctic ice sheet first formed about 35 million year ago when the global climate suddenly cooled. Scientists call this the shift from the "hot house" to the "ice house." Since Antarctica was already in a polar position, the first glaciers formed on the polar mountaintops – the Transantarctic and Gamburtsev Mountains.
Slowly the ice sheet grew to encompass the entire continent. Probably the continental scale blanket of ice grew and shrunk many times until about 14 million years ago when the climate again became colder and a permanent winter embraced the continent. Now the ice piled up in the middle is up to two miles thick and flows toward the continental edges under its own weight. The ice sheet deforms like pancake batter poured onto a griddle. Much of the ice in East Antarctica is frozen to the land beneath and moves very slowly three-to-six feet per year as it flows toward the sea. The flow of the ice sheet means the commemorative barbershop pole at the South Pole has to be moved every year to keep it aligned over the true rotational South Pole.
Some 796 miles to the west of McMurdo is Dome A, the highest point on the ice sheet. Dome A rises over 13,000 feet (3,963 m) above sea level. We will have a camp on either side of the Dome. The U.S.- supported camp will be on the southern side at an elevation of 9,840 feet (3,000 m). The crews have been assembling the camp for almost three weeks now. It has become a regular stopping point for the C-130 flights as they deliver cargo, snow machines, food and fuel. The good news is the air crews have figured out how to take off without using solid fuel rocket thrust boosters. This is important, because the JATO bottles are heavy and decrease the amount of science cargo we can bring in.
On the north side of Dome A, there is also movement. Today the last delivery of fuel by the U.S. Air Force was completed, as the final 34 bundles of aircraft fuel slipped off the back of the C-17 jet. Eric, the northern camp manager, and Sharon, the “ski-way” girl, are on the ground at the northern camp. Sharon is beginning to construct a safe place for the aircraft to land by knocking down the two-to-three foot "sastrugi," firm wind-blown ridges of snow. In just one day, using an ATV with tank-like tracks instead of wheels, she should have polished the surface of the ice sheet so a Twin Otter can land. After three days of polishing, the larger Basler will be able to land. Then they will be able to start building the tents and collecting the fuel drums. In just six days, by the time the British team acclimatizing at the South Pole is ready, they should have a polished skiway, and a secure (if spartan) camp ready. Then the survey will begin.
At last, with the arrival of the clear weather, people are moving.
Photo courtesy of Robin Bell
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