Scientists have just stumbled upon a truly amazing discovery in Antarctica, solving a huge mystery that has plagued scientific circles for more than 100 years. Antarctica’s famous “Blood Falls” were first discovered all the way back in 1911, but scientists had been unable to explain what caused the weird river of blood that flowed through one area and then spilled over a cliff into the sea. Now, however, one group of researchers think they have an explanation.

A study out of the University of Alaska Fairbanks claims that this blood red river is actually liquid rust. More specifically, it’s an iron-rich brine that is oxidizing as soon as it emerges from the depths deep below the glacier and makes contact with the oxygen in the air. It’s a far cry from the theory scientists had come up with before, which was that it was some kind of special algae.

This brine apparently comes from an incredibly salty lake that is trapped underneath the glacier. It is so salty, in fact, that it cannot freeze, and it is therefore able to scrape up iron from the bedrock, which then oozes out of the ice and into the open air.

The statement from the university follows below.

A research team led by the University of Alaska Fairbanks and Colorado College has solved a century-old mystery involving a famous red waterfall in Antarctica. New evidence links Blood Falls to a large source of salty water that may have been trapped under Taylor Glacier for more than 1 million years.

The team’s study, published in the Journal of Glaciology, describes the brine’s 300-foot path from beneath Taylor Glacier to the waterfall. This path has been a mystery since geoscientist Griffith Taylor discovered Blood Falls in 1911.

Lead author Jessica Badgeley, then an undergraduate student at Colorado College, worked with University of Alaska Fairbanks glaciologist Erin Pettit and her research team to understand this unique feature. They used a type of radar to detect the brine feeding Blood Falls.

“The salts in the brine made this discovery possible by amplifying contrast with the fresh glacier ice,” Badgeley said.

Blood Falls is famous for its sporadic releases of iron-rich salty water. The brine turns red when the iron contacts air.

The team tracked the brine with radio-echo sounding, a radar method that uses two antenna — one to transmit electrical pulses and one to receive the signals.

“We moved the antennae around the glacier in grid-like patterns so that we could ‘see’ what was underneath us inside the ice, kind of like a bat uses echolocation to ‘see’ things around it,” said co-author Christina Carr, a doctoral student at UAF.

Pettit said the researchers made another significant discovery – that liquid water can persist inside an extremely cold glacier. Scientists previously thought this was nearly impossible, but Pettit said the freezing process explains how water can flow in a cold glacier.

“While it sounds counterintuitive, water releases heat as it freezes, and that heat warms the surrounding colder ice,” she said. The heat and the lower freezing temperature of salty water make liquid movement possible. “Taylor Glacier is now the coldest known glacier to have persistently flowing water.”

Pettit said she enlisted Badgeley as an undergraduate student to help with the overall mission of understanding the hydrological plumbing of cold-based glaciers.

“Jessica’s work is a perfect example of the high level of work undergraduate students can do when you give them a challenge and set the expectations high,” she said.

Here’s an excerpt from Wikipedia on Blood Falls.

Blood Falls is an outflow of an iron oxide-tainted plume of saltwater, flowing from the tongue of 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 metres (1,300 ft) of ice several kilometers from its tiny outlet at Blood Falls.

The reddish deposit was found in 1911 by the Australian geologist Griffith Taylor, who first explored the valley that bears his name.[1] The Antarctica pioneers first attributed the red color to red algae, but later it was proven to be due to iron oxides.

Poorly soluble hydrous ferric oxides are deposited at the surface of ice after the ferrous ions present in the unfrozen saltwater are oxidized in contact with atmospheric oxygen. The more soluble ferrous ions initially are dissolved in old seawater trapped in an ancient pocket remaining from the Antarctic Ocean when a fjord was isolated by the glacier in its progression during the Miocene period, some 5 million years ago when the sea level was higher than today.

Unlike most Antarctic glaciers, the Taylor glacier is not frozen to the bedrock, probably, because of the presence of salts concentrated by the crystallization of the ancient seawater imprisoned below it. Salt cryo-concentration occurred in the deep relict seawater when pure ice crystallised and expelled its dissolved salts as it cooled down because of the heat exchange of the captive liquid seawater with the enormous ice mass of the glacier. As a consequence, the trapped seawater was concentrated in brines with a salinity two to three times that of the mean ocean water. A second mechanism sometimes also explaining the formation of hypersaline brines is the water evaporation of surface lakes directly exposed to the very dry polar atmosphere in the McMurdo Dry Valleys. The analyses of stable isotopes of water allow, in principle, to distinguish between both processes as long as there is no mixing between differently formed brines.[2]

Hypersaline fluid, sampled fortuitously through a crack in the ice, was oxygen-free and rich in sulfate and ferrous ion. Sulfate is a remnant geochemical signature of marine conditions while soluble divalent iron likely was liberated under reducing conditions from the subglacial bedrock minerals weathered by microbial activity.