The Supra Glacial Stream

Matt Nolan, a professor at the University of Alaska Fairbanks, spends most of his time studying the changes in glaciers and his projects range from hydrology, limnology, and science outreach, to glaciology, which is his favorite.
Meltwater on the surface of the glaciers drains into small streams that feed into this large one, which has melted itself several meters into the glacier. The stream ends in a moulin - a more or less vertical shaft carrying this melted-water to the bottom of the glacier. Falling into this stream is not advised. LINK