Produced by: Mohsin Shaikh
Antarctica’s Blood Falls is a mysterious crimson flow in the McMurdo Dry Valleys, discovered in 1911 by geologist Thomas Griffith Taylor. The bright red water seeping from the glacier into the ocean has captivated scientists for decades.
At first, Thomas Griffith Taylor theorized that red algae in the water caused the striking color of Blood Falls. While plausible, this explanation failed to fully capture the strange nature of the phenomenon.
Another baffling feature: the water, despite the region's average temperature of -19°C, doesn’t freeze. The sight of liquid water flowing in such a cold environment left researchers stumped for years.
In 2003, researchers at the University of Alaska Fairbanks, including National Geographic explorer Erin Pettit, cracked the case using radio-echo technology. The key discovery? The water’s high salt content, which prevents it from freezing.
The water at Blood Falls contains double the salt levels of nearby seawater, pushing up its freezing point. This unusual salinity allows the briny water to remain liquid despite the extreme cold of Antarctica’s environment.
The iron content in the water adds another layer to the mystery. When the iron-rich water meets oxygen, it oxidizes, turning the flow into shades of red, orange, and brown, mimicking the color of blood.
Researchers traced the origin of the water back 1.5 million years. At that time, a salty lake existed where Blood Falls is now. Eventually, a glacier moved over it, trapping the water beneath the ice until it resurfaced through the glacier.
Erin Pettit explained that water releases heat as it freezes, warming the surrounding ice. Combined with the salty brine’s lower freezing point, this process makes the persistent flow of water beneath Taylor Glacier possible.
Credit: Inspiringgirls.org
Taylor Glacier is now known as the coldest glacier with continuously flowing water, thanks to the unique conditions of the trapped brine. Pettit’s study, published in Nature, solved one of Antarctica’s longest-standing mysteries.