The Last Mystery of Antarctica’s ‘Blood Falls’ Has Finally Been Solved

there is one A corner of Antarctica that looks like something from a David Cronenberg film. It is located in the Dry Valleys of McMurdo, a vast frozen desert where, from time to time, a stream of scarlet fluid suddenly erupts from the dazzling whiteness of the Taylor Glacier.. They are called Blood Falls, and since their discovery by geologist Thomas Griffith Taylor in 1911, they have fueled a century of scientific speculation.

More recently, a series of observations from 2018 have clarified several mysteries, such as the nature of their red color and why they remain liquid at around -20 °C. New research published this week in the journal Antarctic Science adds the final piece to the puzzle, clarifying what events trigger the fall from underground.

science behind blood loss

At the time of its discovery, Taylor attributed the color to the presence of red microscopic algae. More than a century later, scientists have determined that the red color is caused by iron particles trapped in nanospheres, along with other elements such as silicon, calcium, aluminum and sodium. These were probably produced by ancient bacteria trapped underground in the area: once exposed to air, the iron oxidizes, giving the mixture its distinctive rust-like colour.

As far as the presence of liquid water is concerned, it is actually a hypersaline salt water, which was formed about 2 million years ago when the waters of the Antarctic Ocean receded from the valleys. The extremely high salinity of this brine prevents the water from freezing, causing it to erupt periodically.

new discovery

Even after the mystery of temperature was solved, the question remained as to what physically caused the liquid to burst. The answer comes from cross-referencing GPS data, thermal sensors, and high-resolution images collected during an eruption in 2018. Analysis showed that the blood fall was the result of pressure variations affecting salty deposits beneath the glacier.

As Taylor Glacier slides downstream, the mass of ice above compresses the subglacial channels, creating tremendous pressure. When the stress becomes unbearable, the ice gives way: pressurized brine seeps into cracks and gushes out in small gushes. Interestingly, this release acts as a hydraulic brake, temporarily slowing the glacier’s march. With this discovery, the mysteries of Blood Falls should have finally been solved, at least for now. The impact of global warming on this complex system in the coming decades remains unknown.

This story originally appeared on WIRED Italia and is translated from Italian.