December 30, 2008 | 1
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 fifteenth of her updates on the effort as part of ScientificAmerican.com’s in-depth report on the "Future of the Poles."
AGAP SOUTH CAMP, ANTARCTICA —Yesterday morning the sky at the South Pole had the kind of ‘iffy’ look that made my stomach turn. Instead of the normal brilliant blue, there were clouds on the horizon and sparkling ice crystals blowing past in the air. Allan Meredith, chief pilot for the British Antarctic Survey, was set to do the first shuttle up to camp with three young scientists and the generator mechanic. I was to follow just after lunch with the load of science cargo. Finally our survey aircraft SJB, or Sierra Julia Bravo as I call her, would carry two scientists up while collecting data lines, and then zip back to South Pole to pick up two more scientists and collect another line of data. The British have already collected 5 lines of data in this region, but these will be our first lines in the prime target area.
Although we had worried we might not be able to fly, at last we were cleared to move forward. My flight left before the red British plane returned. We had tossed all the cargo, including the Christmas decorations for the camp, into the plane and David Braaten from the University of Kansas and I settled into the back.
Quickly the telescopes and lines of cargo that characterized South Pole disappeared and there was nothing but white snow in every direction. We watched my barometer watch as the un-pressurized aircraft climbed up over the Clean Air Zone. The pilots were supposed to offer us oxygen, but they simply announced over the loud speaker that we should not worry, because we would be descending from the “ridiculous” height soon. My watch showed a pressure equivalent of 15,500 feet above sea level. I decided the best defense was a quick nap.
When I woke up from my nap, we had descended to a lower “less ridiculous” altitude. We could breathe a little better and could see the surface of the ice sheet. The first hundred meters of the ice sheet consist of snow slowly turning into ice. Slowly with depth, the spaces between the individual ice snowflakes or ice crystals are driven out as the ice sheet is formed. From the aircraft window, the windblown drifts on the ice sheet surface were evident. At the northern camp, these concrete-like drifts, called sustrigi, caused delays in the opening. The three-foot high drifts were tough even for a ski equipped Twin Otter to land on. The Australians groomed the surface of the ice sheet non-stop for several days before the aircraft could return. Our survey aircraft, with the antennae hanging down from the wings, cannot land just anywhere. We have to land on a groomed skyway. Our camp has a three-mile long skyway suitable for C-130s and Twin Otters ready for geophysical surveys.
The angle of descent increased. I had been sprawled on top of boxes of cargo staring out the window. As the plane banked, I could see the track vehicle grooming the skyway. The cluster of small cloth sided structures came into view. At last I had arrived at the camp.