Drilling; Ice Ages; Ice Caps; Ice Cores; Paleoclimatology | After hauling their equipment to 5325 meters above sea level, scientists set up a small gas-powered drill. While there are minor variations in drilling technology and techniques, all drills use the same basic idea: a drill bit is lowered into the core hole and cuts out a cylinder of ice that is then carefully extracted from the core sleeve and analyzed both on site and in the laboratory. Since snow accumulates more slowly at the Dunde Ice Cap in China, ice from its 140 meter cores is significantly older than that from Quelccaya in the Peruvian Andes. While Quelccaya provides high-resolution clues to the last 1500 years of climate, Dunde stretches back over 40,000 years, well into the last ice age. | 
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