Denmark: Buried underneath compacted snow and ice in Greenland lies a large liquid water reservoir that has now been mapped by researchers using data from NASA's Operation IceBridge airborne campaign.
A team of glaciologists serendipitously found the aquifer while drilling in southeast Greenland in 2011 to study snow accumulation. Two of their ice cores were dripping water when the scientists lifted them to the surface, despite air temperatures of minus 4 F (minus 20 C). The researchers later used NASA's Operation Icebridge radar data to confine the limits of the water reservoir, which spreads over 27,000 square miles (69,930 square km) – an area larger than the state of West Virginia. The water in the aquifer has the potential to raise global sea level by 0.016 inches (0.4 mm).