Layer of liquid water hidden under snow on Greenland

BBC : The melting of the ice sheets on Greenland is considered one of the major causes of sea-level rise, with 34 billion tons of ice melting between 1992 and 2001 and 215 billion tons between 2002 and 2011. To better understand those ice sheets, Richard Forster of the University of Utah and his colleagues in the spring of 2011 drilled into a layer of partially compacted snow known as firn . The researchers were surprised to find that liquid water flowed to the top of the drill holes despite an air temperature of −15°. Because the drilling occurred before the summer melt period, Forster’s team believes that the water stayed liquid through the winter. The layers of snow that fall on top of each other serve as an insulator to keep the water in the layer liquid, creating a slush similar to a snow cone . By the team’s estimate, the layer covers an area the size of Ireland and holds about 150 billion tons of liquid water. However, they still don’t know whether the layer is isolated or if it drains to the ocean, where it contributes to the yearly rise in sea levels.