Blood Falls seeps from the end of the Taylor Glacier into Lake Bonney in the Antarctic. Scientists believe a buried saltwater reservoir is partly responsible for the discoloration, which is a form of reduced iron. The tent at left provides a sense of scale for just how big the phenomenon is. Photo by Peter Rejcek, courtesy of the National Science Foundation, Wikimedia Commons
Blood Falls is an outflow of an iron oxide-tainted plume of saltwater, occurring at the tongue of the Taylor Glacier onto the ice-covered surface of West Lake Bonney in the Taylor Valley of the McMurdo Dry Valleys in Victoria Land, East Antarctica.
Iron-rich hypersaline water sporadically emerges from small fissures in the ice cascades. The saltwater source is a subglacial pool of unknown size overlain by about 400 meters of ice at several kilometers from its tiny outlet at Blood Falls.
Image credit: Wikimedia Commons