Blood Falls, named for its ruddy colour, is not, in fact, a gush of blood from some unseen wound.
The colour was initially chalked up to red algae, but a new study in the Journal of Glaciology has uncovered its true origin using radar to scan the layers of ice from which the river pours.
Located in Antarctica’s McMurdo Dry Valleys, the falls pour forth from Taylor Glacier, and the liquid bubbles up from fissures in the glacier’s surface.
The flow was previously a mystery, as the mean temperature is -17 degrees Celsius and little glacial melting can be seen at the surface.
Imaging from underneath the glacier helped solve the mystery, revealing a complex network of subglacial rivers and a subglacial lake—all filled with brine high in iron, giving the falls its reddish tint.
According to the study, the makeup of the brine explains the fact that it flows instead of freezes.“The brine remains liquid within the subglacial and englacial environments through latent heat of freezing coupled with elevated salt content,” the study explains.