Greenland's icy regions are experiencing above-average melting this summer, as seen in these before-and-after images taken by NASA. The images of the Frederikshåb Glacier, snapped on June 14 and July 24 respectively, show a dramatic decline in snow and ice cover in just one month. NASA added, "Also visible in the images is the transition from “clean” to “dirty” snow – due primarily to impurities left behind from snow melting – and dark blue melt ponds that form when meltwater pools in low spots