Scientists have been wondering for more than 100 years why a glacier in Antarctica seems to be bleeding.
According to a study recently published in the Journal of Glaciology, there's actually a simple explanation for the gruesome "Blood Falls" at the Taylor Glacier.
A large source of salty water turns the water blood red, then streaks down the bright white surface for an ominous look.
That find led to yet another discovery -- liquid water can exist within a frozen glacier. Salt water has to be colder than fresh water to freeze, so some of it remains liquid.
A from the University of Alaska Fairbanks and Colorado College found that the glacier not only has a lake underneath it, it also has its own water system which has been flowing for all of human history.
Taylor Glacier is now the coldest known glacier with persistently flowing water.
See photos of the phenomenon: