A research team has solved a century-old mystery involving a famous red waterfall, known as Blood Falls, in Antarctica, by pointing to a source of salty water.
Blood Falls, found in 1911 by the Australian geologist Griffith Taylor, is famous for its sporadic releases of iron-rich salty water 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 of East Antarctica, Xinhua news agency reported.
The brine turns red when the iron contacts air, a mystery since its finding.
In a study published in the Journal of Glaciology, the research team led by the University of Alaska Fairbanks (UAF) and Colorado College described the brine's path of 300 feet or about 91 meters from beneath Taylor Glacier to the waterfall, and new evidence linking it to a large source of salty water that may have been trapped under the glacier for more than one million years.
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," co-author Christina Carr, a doctoral student at UAF, said.
"The salts in the brine made this discovery possible by amplifying contrast with the fresh glacier ice," said lead author Jessica Badgeley.
UAF glaciologist Erin Pettit said her team made another significant discovery that liquid water can persist inside an extremely cold glacier, against previous belief among scientists that this was nearly impossible.
"While it sounds counterintuitive, water releases heat as it freezes, and that heat warms the surrounding colder ice," she explained.
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."