In biting, unparalleled coldness, Thomas Griffith Taylor traverses a pale desert. He is accompanied by the ghostly howling of a wind that pushes back, roaring crackles heralding the birth of new glaciers, and the clack of his teammates’ boots against the ice as they follow him into a hazy horizon. In Antarctica, the coats of white layered over ridges and valleys transform an astounding but ultimately earthly landscape into an entirely alien one. 

Taylor sees black mountains marbled by alabaster snow. Yet, as he wipes the blurriness from his eyes, something defies the color palette of whites, grays, and blues that had become almost monotonous – a startling crimson. In the distance, abundant red flows out of a glacier like blood from an open wound, as if someone had carved a gash directly onto earth itself. What kind of feeling did this sight evoke within the expedition team? Did shivers run down their spine at the eerie appearance of an impossible, inorganic injury? Was it profound empathy from witnessing a kind of vulnerability you had to travel to the ends of the earth to see?

But as geologists of the Terra Nova expedition tasked to explore Antarctica in 1911, it must have been curiosity that presided over all else. The feature was aptly named Blood Falls, and in the decades that followed, numerous scientists would be equally fascinated by this phenomenon, endeavoring to uncover its mysteries.

As research into environmental conditions was carried out at this site, scientists discovered several unique features that provided clues to the waterfall’s true nature. The water emerges clear from the glacier at a temperature below freezing. An extremeley high salinity of 75 parts per thousand further eliminates the possibility of the water originating from a glacier melt. Using methods like radio-echo sounding, researchers mapped out a complex network of groundwater deep beneath the glaciers that had been flowing for millions of years.¹ A combination of pressure and salinity keeps the water moving up, but this did not account for how the water would quickly turn red upon exposure to surface air. Initially, scientists attributed this to the weathering of iron-rich minerals. In 2022, however, researchers found small red solids populating the collected water samples. These solids were nanospheres, structures 100 times smaller than a red blood cell. Though they cannot be classed as minerals, they carry high amounts of iron that oxidize once they reach the surface of Antarctica – transforming the landscape into an unsettling red.⁴ 

With all these factors in mind, Blood Falls is an extreme of extremes. According to hydrogeologist Peter Doran, it exists as an outlier even in Antarctica’s conditions. With an exceptionally high salt content, little to no oxygen, and being in complete darkness, the waters of Blood Falls seem like the last place for any ecosystem to thrive. Yet, as a demonstration of the resilience and adaptability of life, at least 17 different types of microorganisms were being sustained in this environment.² By isolating these bacteria, scientists unearthed unique processes where sulfur and iron are metabolized, providing insight into extremophiles–organisms able to live in extreme environments.³ Specifically, understanding how halophiles (organisms surviving in extreme salinity) and psychrophiles (organisms surviving in extreme cold) contribute to their ecosystem and subglacial processes provides a unique opportunity to study extraterrestrial conditions. For many, an ecosystem functioning under such extreme conditions provides exciting clues as to what kind of life may inhabit the ice caps of Mars or Europa’s acid oceans. From its historical discovery over 100 years ago to its possible future applications to space exploration, Blood Falls embodies the spirit of discovery and curiosity in a manner that transcends time. 

References

1. Badgeley, J. A., Pettit, E. C., Carr, C. G., Tulaczyk, S., Mickuki, J. A., & Lyons, W. B. (2017). An englacial hydrologic system of brine within a cold glacier: Blood Falls, McMurdo Dry Valleys, Antarctica. Journal of Glaciology, 63(239), 387–400. doi:10.1017/jog.2017.16
2. Grom, J. (2009, April 16). Ancient Ecosystem Discovered Beneath Antarctic Glacier. Science. Retrieved March 31, 2024, from https://www.science.org/content/article/ancient-ecosystem-discovered-beneath-antarctic-glacier
3. Mikucki, J. A., & Priscu, J. C. (2007). Bacterial Diversity Associated with Blood Falls, a Subglacial Outflow from the Taylor Glacier, Antarctica. In Applied and Environmental Microbiology (Vol. 73, Issue 12, pp. 4029–4039). American Society for Microbiology. https://doi.org/10.1128/aem.01396-06
4. Sklute, E. C., Mikucki, J. A., Dyar, M. D., Lee, P. A., Livi, K. J. T., & Mitchell, S. (2022). A Multi-Technique Analysis of Surface Materials From Blood Falls, Antarctica. In Frontiers in Astronomy and Space Sciences (Vol. 9). Frontiers Media SA. https://doi.org/10.3389/fspas.2022.843174