Greenland’s largest outlet glacier has receded over 40km since 1850 thumbnail: http://svs.gsfc.nasa.gov/vis/a000000/a003800/a003806/Jakobshavn_ortho_68.94N_69.39N_49.212W_51.372W_gal.png

Above the Earth, Below the Surface: Landsat’s Role in Monitoring Water Quality
Safeguarding freshwater resources is crucial, and while scientists use a variety of ground-based techniques to gauge water quality, the Landsat program has provided water quality data from orbit for decades.