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...