Water Flow Through Ice Sheets Accelerates Effects of Warming, Study Says

Meltwater that flows into the crevasses and fractures of ice sheets speeds up the warming of these ice sheets more rapidly than current models suggest, according to a new study. In fact, the movement of warmer water, as if through a network of pipes, can accelerate warming of massive ice formations like the Greenland Ice Sheet within decades rather than centuries, researchers at the University of Colorado at Boulder say. While current thermal models typically consider the effects of air temperatures on the ice sheets, the researchers modeled the effects of warmer water flowing through so-called moulins — crevasses and cracks created when the sheets grind over bedrock — during the summer melt season. “We are finding that once such water flow is initiated through a new section of ice sheet, it can warm rather significantly and quickly, sometimes in just 10 years,” said Thomas Phillips, of the Cooperative Institute for Research in Environmental Sciences, who is co-author of the study, published in the journal Geophysical Research Letters. The seepage of meltwater into crevasses in Antarctica’s Larsen B Ice Shelf was a key factor in its rapid disintegration in 2002.