300 years of ice may be squeezed into a meter. Ice at the edge of the glacier may be distorted by this slow tumult, so scientists try to drill near the center, where deformation has been least severe, he says. For a core to be useful, annual deposition layers must be discernible and in their original order, not flipped or twisted. Each year is represented by two layers, winter and summer, visible as banding because of atmospheric dust trapped within, he says. Nice Most research on ice cores revolves around the paleoclimate of earth, Cravens says.
Ice contains tiny pockets of gas, essentially captured fragments of atmosphere.
Scientists can tap into the pockets and determine gas ratios in the ancient air. Combined with other data, this can yield a model for ancient climate change, Cravens says. I know he said this, but it ain't right. Among other things, scientists can use the isotopic composition of the water to determine the temperature that prevailed when the snow fell, as well as the concentration of various gases in the atmosphere carbon dioxide and methane being two important ones. With this informaiton, they discern how temperatures rose and fall in the past, and whether there were parallel increases and decreases in greenhouse gases.