It鈥檚 a mystery that has baffled scientists for more than a century; how salty, blood-red water is able to ooze out from a million-year-old glacier in a region known for its freezing temperatures.
When explorer and geoscientist Griffith Taylor discovered a 54-kilometre long glacier in Antarctica that released a deep red liquid in 1911, he attributed the strange phenomenon to red algae colouring the moving water.
The outflow was quickly dubbed 鈥淏lood Falls鈥� for the water鈥檚 creepy, red hue contrasting against its icy, white surroundings.
Blood Falls is located at the northern end of Taylor Glacier, a 1.5 million-year-old glacier stretching through Antarctic鈥檚 Transantarctic Mountains, and flows into Lake Bonney.
It was later discovered, however, that the mysterious water was not related to blood or algae at all. In fact, the colour is the result of iron-rich salt water that turns into a reddish-brown shade or oxidizes (like rust) when it comes into contact with the air. Scientists call the water 鈥渂rine鈥� because of the incredible amount of salt in it.
And now, that saltiness has offered an important clue into one of Blood Fall鈥檚 final mysteries 鈥� how the brine travels from within the frozen glacier to the waterfall in sub-zero temperatures. Scientists had previously thought it was nearly impossible for liquid water to exist inside a freezing cold glacier.
Researchers from the University of Alaska Fairbanks and Colorado College believe they solved the century-old question after they traced the 91-metre path using radio echo sounding, a radar method that uses antennae to transmit and receive electrical pulses.
鈥淲e 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," one of the study鈥檚 co-authors, Christina Carr, on Monday.
Using this technique, the scientists tracked the reddish brine鈥檚 origins to an ancient salty lake, which may have been trapped underneath the Taylor Glacier for more than a million years.
The researchers found that the glacier had its own unique network of pressurized channels that move the iron-rich water to the top of Blood Falls.
Erin Pettit, a glaciologist at the University of Alaska Fairbanks, said the findings are significant because they show how the freezing process itself and the salty water鈥檚 ability to freeze at a lower temperature can explain the liquid鈥檚 movement through a cold glacier and into a climate with mean annual air temperatures of -17 C.
鈥淲hile it sounds counterintuitive, water releases heat as it freezes, and that heat warms the surrounding colder ice," she said in a statement. 鈥淭aylor Glacier is now the coldest known glacier to have persistently flowing water."
The study has been published in .
