083 The Mysterious Blood Red Flow

What this episode covers

In 1911, during an expedition to the McMurdo Dry Valleys, geologist Thomas Griffith Taylor discovered a strange phenomenon on a remote glacier in East Antarctica: The lily-white ice of the glacier was being stained a deep red by water flowing from deep within the glacier. Taylor had believed it was due to algae discoloring the water, however that hypothesis was never verified. For many years the source of the red color remained a mystery, as the mean temperature is 1.4 degrees Fahrenheit (-17 degrees Celsius) and little glacial melting can be seen at the surface. But in 2017 scientists of the University of Alaska Fairbanks announced that they had discovered the cause. The deep red coloring is due to oxidized iron in brine salt water, the same process that gives iron a dark red color when it rusts. When the iron-bearing saltwater comes into contact with oxygen the iron oxidizes and takes on a red coloring, in effect dying the water to a striking deep red color - and its name, Blood Falls. Roughly two million years ago, the Taylor Glacier sealed beneath it a small body of water that contained an ancient community of microbes. Trapped below a thick layer of ice, they have remained there ever since, isolated inside a natural time capsule. Evolving independently of the rest of the living world, these microbes exist in a place with no light or free oxygen and little heat, and are essentially the definition of “primordial ooze.” The trapped lake has very high salinity and is rich in iron. After that, something eerily magical happens with the by-products. The iron in the water interacts with them to restore the sulphates, basically recycling the sulphates for the microbes to break down into oxygen over and over again. A fissure in the glacier allows the subglacial lake to flow out, forming the falls without contaminating the ecosystem within. Furthermore, the scientists mapped the path of the water that feeds the five-story tall falls and explores how water can exist under the ice, unravel the inner workings of glaciers.