The Blood Falls of Antarctica are weird, but not inexplicable. Tumbling out of the Taylor Glacier, they aren’t a sign of the coming apocalypse or the Rapture – it’s a form of meltwater that is tainted by iron oxide, essentially rust, that ekes out of small fissures in the ice.
The color was initially thought to have come from red algae, which certainly does exist – however, it could be explained by a strange quirk of geochemistry, where iron particles in unfrozen saltwater become oxidized when they flow up the surface and make contact with the atmosphere.
The bewitching Blood Falls were discovered for the first time all the way back in 1911, but the genesis and the path of the source river remained shrouded in mystery for generations. The former, clearly, has been solved, and now it looks like the latter has been too.
According to a new study in the Journal of Glaciology, it appears that the red river first emerges from a saltwater lake trapped beneath the 1.5-4-million-year-old Taylor Glacier. The team led by Colorado College and the University of Alaska Fairbanks spotted the source of the crimson brine using penetrating radar methods to see through the thick layers of overlying ice.
Far from there being just a single concealed river, it appears Taylor Glacier is sitting atop a complex network of them, all acting as a drainage system in unison. The brine appears to be injected into the ice, and forced up to the Blood Falls through cracks, under immense pressure.
Saltwater has a lower freezing point than freshwater, but the glacier’s temperatures are so low that researchers have been puzzled as to how it’s managing to flow through it without solidifying. This new study explains that the saltwater releases latent heat as it freezes, which melts the surrounding ice and allows it to quickly flow through.
This makes Taylor Glacier the coldest glacier on Earth to feature constantly flowing water. More significantly, this means that Blood Falls are at least a million years old, perhaps older.
Modeling shows that the brine is forcing its way through the Taylor Glacier through multiple paths, all the way up to Blood Falls (magnified, inset). Badgeley et al./Journal of Glaciology
Thanks to scientific curiosity, the mystery of Blood Falls is being stripped away year by year, but this peculiar phenomenon’s inherent weirdness looks set to become more pronounced over time. For example, a rather strange microbial system, one that makes use of the sulfates and iron oxides present in the water to produce energy, has also been detected in Blood Falls.
Back in 2009, researchers clocked at least 17 different varieties of microbes all living in an essentially deoxygenated environment, and several of them use energy-production processes that were previously unknown to science. So Blood Falls, an extremely strange place, has actual extremophiles living in it.