The Last Mystery of Antarctica’s ‘Blood Falls’ Has Finally Been Solved

Antarctica’s Blood Falls, a striking crimson outflow in the McMurdo dry valleys discovered in 1911, have long puzzled scientists regarding their unusual color, liquid state at subzero temperatures, and the mechanism behind their periodic eruptions. Recent research has clarified that the red hue results from iron particles oxidizing upon exposure to air, originating from ancient bacteria trapped underground. The liquid is a hypersaline brine formed around two million years ago when the Antarctic Ocean receded, with its high salinity preventing freezing even at nearly –20°C. The latest breakthrough, based on 2018 data combining GPS, thermal sensors, and imagery, revealed that the eruptions are driven by pressure changes beneath the glacier. As Taylor Glacier moves, it compresses subglacial channels, building pressure until the ice fractures, releasing bursts of pressurized brine through crevices. This release also temporarily slows the glacier’s movement, acting as a hydraulic brake. While these findings solve the longstanding mysteries of