January 6, 2009 | 2
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 sixteenth 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—Since we first conceived this project, we have been acutely aware of the limited amount of time we would have in the field. We wanted 35 days to complete the planned program. Woody Harrison, head of camp construction, and I argued incessantly over this during the spring planning meeting. I wanted every possible day in the field for science, and he did not want his crew to get caught in the bitterly cold early winter when it closed the camp after we finished. I lost the battle; we were given only 25 days. We had to cut the survey by 30 percent. Additional delays have hounded us since our arrival in Antarctica. We arrived at camp with only 20 days to complete the work. The operational rules for the aircraft are very restrictive. We could not fly on Sunday to allow for rest, even though the weather was beautiful. Then we could not fly on Tuesday, because the weather forecasters predicted bad visibility. Ironically a team in Charleston, S.C., forecasts weather in East Antarctica – sometimes accurately, sometimes not.
Combine these two setbacks with the holidays and two blizzards, and the result has been slow progress. We had planned on 1.85 flights daily, but we are averaging only 1.5 a day. On a good day, we complete four flights. If we have clear weather, and are allowed to fly, we have the chance to recover, but we simply need more time. I am back to arguing for more time in the field. Iridium phones, modems and even Twitter are letting me stay in touch with the decision-makers in McMurdo and Washington. I am not sure words are working. It is hard to see that this is part of the science, and sometimes I feel ridiculous talking on the phone, tucked behind a large pile of orange boxes atop 3 kilometers of ice.
We have only flown 16 flights and we hope to fly 50. Even though we are behind with only 25 percent of the flights complete, we are beginning to form an image of these hidden mountains. Our camp is in the southern foothills. When we fly north, we find a steep escarpment that marks the first elevated terrain. By piecing together the radar data, we are beginning to see the shape of the buried valleys in the mountain ranges. Most are deep V-shaped features that were probably carved by rivers before the ice sheet covered the continent. There are a few U-shaped valleys that suggest that glaciers did etch some of the terrain before the deep freeze. The radar profiles show the terrain along the lines we are flying while the gravity provides an overview of the mountains backbone. It is remarkable that we are atop the polar plateau and beginning to see what is below the flat white ice that surrounds us.
The camp staffers, who are working side by side with us to keep the aircraft collecting data, are eager to send copies of the preliminary data home to their families and friends. We select a short radar profile to send along to them. I realize that a picture might be more effective than words, so I send the radar image.
This cross section of just 60 kilometers close to camp touches off a geyser of enthusiasm. Suddenly people realize we are actually collecting data—and that it is beautiful. Many people perk up at the small image we were able to push across the satellite modem. I even hear back from Woodie, the camp construction manager, hoping that we can stay a bit longer. We have collected 12,000 km of data so far, only a slice of the 70,000 km. we are hoping to gather. Perhaps there is a chance we can reach our goal.
Each night after dinner we all sit around drinking tea and pretending we are not waiting for the weather forecast. Tonight we are in luck: there is a window of good flying weather between low-pressure systems. The plane is heading toward the northern camp. If the weather holds, maybe we will be able to finish.
Photo credit: Robin Bell