Scientists Unravel the Mystery of Antarctica’s Blood Falls

Scientists Unravel the Mystery of Antarctica’s Blood Falls

new answer for what makes Antarctica's Taylor Glacier weep ruddy tears.
The phenomenon - known as Blood Falls for its distinctive colour - was previously attributed to red algae from under the ice sheet, but a new study points to a different culprit.
Scientists have been investigating how running water flows from the 1.5 million-year-old glacier for more than 100 years, since the falls' discovery in 1911. The mean temperature of the surrounding air is an icy -17oC, sparking debate as to how regularly running water was possible at all

The research team, operating out of the University of Alaska and Colorado College, used radio echo sounding - sort of like a bat's echolocation - to track the origin of the water under the glacier and found a surprising result; a large source of salt water that may have been trapped under the glacier for more than 1 million years.
Their new study, released this week, pins the process on this pool of salt water - so salty they refer to it as brine - which dramatically lowers the freezing temperature, and the actual process of freezing itself.
If we take a brief trip back to high school science class, you might recall the molecules of liquid water have more energy than those of frozen water. In order to freeze, that energy must be released, as heat - known as 'latent heat of freezing'. "While it sounds counter-intuitive," study co-author Erin Pettit said in the team's press release, "water releases heat as it freezes, and that heat warms the surrounding colder ice."
Salt-rich water is injected at variable cracks along the base of the glacier; water which then begins to freeze, releasing heat into the surrounding ice.

most of us, if we encountered what was obviously a waterfall of blood, would turn tail and run. 
However, geologist Griffith Taylor was made of sterner stuff when he discovered Blood Falls in the early 1900s. This flow of red liquid on Taylor Glacier in Antarctica has been perplexing scientists since it was discovered, but they’ve finally figured it out. No, it’s not actually blood. Thank goodness.

When Taylor (after whom the glacier was named) found Blood Falls, he believed it to be the result of algae blooms on the glacier that were washed into West Lake Bonney. Some species of algae have been known to cause similar discolorations. That would have been proof positive that life was more hearty than believed at the time. Of course, we’ve found organisms since then that are capable of living in even more harsh conditions, but it wasn’t algae that was responsible for Blood Falls.

An analysis in 2003, which laid the groundwork for the most recent discoveries, confirmed it was not algae that caused the red flow into West Lake Bonney. The water was found to contain extremely high levels of iron. The iron atoms in the water turned red when exposed to air — they actually become iron oxide, also known as rust. So, this isn’t blood or algae, but water with rust dissolved in it.

Figuring out what caused the red color was not the end of the mystery, though. Researchers suspected that the iron-rich water was coming from an ancient source, at least 5 million years old. There didn’t appear to be any liquid water around that would be a match. The answer turns out to be under the glacier’s surface.
Using radio-echo sounding, researchers from the University of Alaska Fairbanks were able to scan the area around Blood Falls. No drilling was necessary. The team found not just a subsurface lake, but an entire network of flowing water with high salt content in addition to iron. The high salinity of the water (also known as brine) prevents it from freezing, like when you sprinkle salt on your icy steps during the winter. The salt content of the water made this discovery possible due to its high contrast
in radar reflection

Researchers now say that Taylor Glacier represents the oldest known example of flowing water in a glacier. This research could help us understand the way water can persist inside other extremely cold glaciers
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