The final mystery of Antarctica’s Blood Falls has finally been solved

there corner Antarctica It looks like something out of a David Cronenberg movie. It is located in the McMurdo Dry Valleys, an enormous frozen desert, where from time to time a stream of crimson liquid suddenly flows out of the dazzling white of the desert. Taylor Glacier. They are called Blood Falls, and since their discovery in 1911 by geologist Thomas Griffith Taylor, they have fueled a century of scientific speculation.

Recently, a series of observations conducted since 2018 have clarified several mysteries, such as the nature of its reddish color and what keeps it liquid at around 20 degrees Celsius. New research published this week in the journal Antarctica Science He adds the final piece to the puzzle, explaining the phenomena that cause waterfalls to flow from underground.

The science behind blood falls

At the time of their discovery, Taylor attributed the color to the presence of red microalgae. More than a century later, scientists determined that the red color was due to iron particles trapped in the nanosphere along with other elements such as silicon, calcium, aluminum and sodium. These bacteria were likely produced by ancient bacteria trapped underground in the area: once in contact with air, the iron oxidized, giving the mixture its characteristic rust color.

As for the presence of liquid water, it is actually very salty water, formed about 2 million years ago when the waters of the Antarctic Ocean receded from the valleys. The very high salinity of this brine prevents the water from freezing, allowing it to flow periodically.

The new discovery

With the temperature mystery solved, the question remained as to what caused the liquid to explode. The answer came through cross-referencing GPS data, thermal sensors, and high-resolution images collected in 2018 during the volcano’s eruption. Analysis showed that the blood falls are the result of pressure changes affecting saltwater deposits beneath the glacier.

As Taylor Glacier slides downstream, the ice mass covering the subglacial channels compresses, building up enormous pressure. When the pressure becomes unbearable, the ice collapses: pressurized brine seeps into the cracks and is released in short bursts. Curiously, this release acts as a hydraulic brake, temporarily slowing the glacier’s march. With this discovery, the mysteries of Blood Falls should finally be solved, at least for the time being. The impact of global warming on this complex system in the coming decades is still unknown.

This story originally appeared on Wired Italy It was translated from Italian.