The Blood Falls in Antarctica were thought to be red due to algae since the year 1911. Decades later, it was found that the actual cause was iron oxide. Iron minerals dissolve in brine and come in contact with oxygen. This causes oxidation that produces oxides of a red color. This imparts the weird bloody hue to the waterfall, which is located in the McMurdo Dry Valley.
Image: U.S. Department of State on Flickr
The experts who went on the research expedition used radio-echo sounding to image the glacier from its underside. This is how they came across the oxidation process. Apparently, the brine from a lake underneath the Great Tyler glacier takes 1.5 million years to reach the Blood Falls. It picks up minerals from the waterbed on its way there and gushes forth through the glacier.
Image: U.S. Department of State on Flickr
The whole path is around 300ft in length. The way water freezes and responds to heat is pivotal in understanding the mechanism. In the cold environment under the glacier, just the right amount of brine reaches the solid state. This releases heat, allowing the remainder of the brine to stay liquidated. Apart from this, the presence of salts also increases the freezing point of the water.
These findings warrant for a revision of the models of functioning associated with glaciers like Great Tyler.
