Antarctica, as is known with its huge frozen desert and harsh climate, contains a lot of mysterious natural wonders that scientists and explorers keep on finding breathtaking. Amongst the most amazing and intriguing ones is the Blood Falls—a blood-red waterfall running from under the Taylor Glacier to West Lake Bonney, forming a beautiful color contrast against the white snow and ice. But what makes this mysterious sight so special, and how did it come to be known as the Blood Falls?

How was the Blood Falls discovered?

The Blood Falls were a mystery for many years until 1911, when the Australian geologist Thomas Griffith Taylor ventured into Antarctica's remote valleys. On one of his expedition days, Taylor's team chanced upon a strange sight: a stream of deep red water flowing out of an ice crevice at the top of the Taylor Glacier. This surreal, blood-like flow caught the attention of scientists worldwide, and many began speculating about its origins.

Both the glacier and the West Lake Bonney nearby were named after Taylor himself, who had been the first to document such a strange phenomenon. Many initially thought that red algae was what caused the reddish hue of the water, but the reason behind the phenomenon wasn't disclosed until decades later.

What makes the Blood Falls?

It was only in 2003 that scientists from the University of Alaska Fairbanks and Harvard University were able to crack the mystery behind Blood Falls. Equipped with a spectrometer, they analyzed the water and found high iron oxide levels, commonly referred to as rust. This inorganic compound, they concluded, is formed when salty water trapped under the glacier comes into contact with the air.

But how did the salty water remain liquid under the freezing conditions of Antarctica? The reason is the extreme salinity of the lake. Salt levels in the lake are several times that of seawater, so it does not freeze even at freezing temperatures of Antarctica. This exceptional salinity combined with constant pressure beneath the glacier allows the water to remain in liquid form and flow through cracks in the ice.

Life under the ice

The conditions at the bottom of the glacier are extreme. The environment is devoid of light, oxygen, and nutrients, yet life still thrives in the water under the ice. The Blood Falls hosts a microbial ecosystem consisting of extremophiles, bacteria that have adapted to these extreme conditions. The microorganisms survive through a process called chemosynthesis.

During this process, the bacteria absorb sulfur and iron, abundant in water for their use in producing energy, while it may break them since there is the absence of daylight, so among very few biological organisms they survived under these dreadful conditions.

Red water and associated chemical reaction

Once the iron-rich water seeps through the glacier cracks and gets in contact with air, a fast oxidation reaction takes place. The oxygen reacts with the iron in the water, causing the water to rust, thus turning the previously clear water into a deep red color. This is the reason this waterfall appears red in color, which complements the mystique and horror left on this place.

The Blood Falls is not only an immensely beautiful visual phenomenon; it is a living testimony to life on Earth. Conditions beyond the endurable range of life, including extreme cold, lack of sunlight, and scarcity of nutrients, do not dampen the extremophiles thriving beneath Taylor Glacier. Their survival and prosperity under such conditions pose a significant challenge to human understanding of life and what can go wrong under near-impossible conditions.