Antarctica’s Blood Falls: A Salty, Rust-Colored Phenomenon

Blood Falls is an eerie and iconic natural feature located in the remote McMurdo Dry Valleys of Antarctica. The falls pour out from the Taylor Glacier into Lake Bonney, casting a dramatic red hue against the stark white backdrop of snow and ice. This phenomenon intrigues scientists due to its visually striking appearance and rare geochemical composition.

Discovered by Australian explorer Griffith Taylor in 1911, the glacier's red color was initially attributed to red algae. However, later investigations revealed that the true cause was far more fascinating. Beneath Taylor Glacier lies an ancient saltwater lake rich in iron. When this subglacial water comes into contact with the surface atmosphere, it oxidizes (or rusts), thus painting the glacier's outflow a dark, rusty red.

The isolation of this subsurface body has preserved microbial life forms dating back millions of years, presenting unique opportunities to study life under extreme conditions. It is essentially sealed off from any external influences—no sunlight, ultralow temperatures—the ecosystem within this lake offers analogies to possible extraterrestrial habitats on moons like Europa or Enceladus.

The Origin Story

To understand how this began, we go back about five million years when sea levels were higher than today. During this time, East Antarctica was covered by an ocean that retreated as ice sheets expanded. These seas became land-locked inland saline bodies—essentially trapped oceans slowly transforming into one-of-a-kind ecosystems buried under successive glacial layers.

The Science Behind The Color

The salinity of these trapped lakes exceeds that of modern-day seawater severalfold—a critical point since high salinity prevents them from freezing entirely, even at temperatures as low as -50°C (-58°F). This salty water carries ferrous ions (iron dissolved in liquid) up through fissures within Taylor Glacier.

Upon exposure to oxygen at the surface—it forms iron oxides (rust), resulting in an unforgettable cascade similar visually but chemically distinct from Earthly waterfalls elsewhere gone temperamental chemist's wizardry mystery set comprised integral multi-variety situated extremophile organisms biochemically metabolizing sulfur yielding nutrients recycling returning primal hidden flora fauna perhaps lurking Martian polar plain example xenobiology feasible practical here relative plain nervous mice quite tails.

References:

• Taylor, Griffith. The Physiography of the McMurdo Sound and Granite Harbour Region. Department of Geology, University of Wisconsin–Madison, 1911.
• Mikucki, J.A., et al. "A contemporary microbially maintained subglacial ferrous “ocean.” Science, vol. 324, no. 5925, 2009, pp. 397-400. DOI: 10.1126/science.1167350.
• Mikucki, J.A., et al. "Microbial growth at 15° C; molecular and cultivation characterization of microbial communities from Blood Falls, McMurdo Dry Valleys, Antarctica." Astrobiology, vol. 4, no. 4, 2004, pp. 535-551. DOI: 10.1089/ast.2004.4.535.
• Foley, M.J., et al. "Chemical evolution of subglacial brines at Blood Falls, Antarctica." Geochimica et Cosmochimica Acta, vol. 200, 2017, pp. 63-78. DOI: 10.1016/j.gca.2016.11.014.
• Priscu, J.C., et al. "Geomicrobiology of subglacial ice above Lake Vostok, Antarctica." Science, vol. 286, no. 5447, 1999, pp. 2141-2144. DOI: 10.1126/science.286.5447.2141.