Aerial photograph taken on 24 July 2015 over the southwest portion of the Greenland ice sheet, near Kangerlussuaq. (left) The turquoise color is characteristic of meltwater on the shore of a supraglacial lake. (center) Area from which the lake water has receded, removing impurities and leaving bare ice. (right) Ice and snow covered by surface impurities. Credit: Marco Tedesco