A valley longer than the Grand Canyon hidden beneath the Greenland ice sheet may carry running water. How quickly it flows may affect how the ice melts
Source:
https://www.newscientist.com/article/2211583-huge-hidden-canyon-under-greenland-ice-sheet-may-have-flowing-water/?utm_campaign=RSS%7CNSNS&utm_source=NSNS&utm_medium=RSS&utm_content=home