Did you know that Antarctica has a unique red waterfall that looks just like flowing blood?
Blood Falls flows directly from the icy terminus of Taylor Glacier into Lake Bonney inside the McMurdo Dry Valleys of Antarctica. Scientific investigations show that a fascinating geochemical reaction transforms this emerging liquid into a deep crimson color as it touches the atmosphere.
An ancient subglacial body of water sits trapped beneath hundreds of meters of solid glacial ice for thousands of years. This isolated subglacial reservoir contains exceptionally high concentrations of dissolved ferrous iron along with heavy salt deposits.
Enormous weight and pressure from the overlying glacier push this salty subglacial liquid upward through deep internal crevasses. The liquid emerges completely clear onto the surface where atmospheric oxygen rapidly alters its chemical state and visual appearance.
Why Is the Water Red?
According to scientific research by Badgeley et al. in the Journal of Glaciology millions of years ago, an advancing polar ice sheet trapped a marine fjord inside Taylor Valley during a major climate transition. Severe freezing over thousands of years concentrated the captured seawater into a thick, highly saline subglacial brine.
Specialized subglacial microbes and chemical weathering with underlying bedrock dissolved immense quantities of iron into the dark brine. A total absence of oxygen underneath the heavy glacier prevented the dissolved ferrous iron from oxidizing or rusting underground.
Geophysical surveys confirmed that a vast subglacial groundwater network holds immense volumes of this iron-rich liquid beneath Taylor Glacier. The extreme salt concentration lowers the freezing point and keeps the buried brine liquid at minus seventeen degrees Celsius.
The sealed subglacial basin remains completely dark and isolated from any direct contact with external air supplies. These static underground conditions preserve the high concentrations of soluble ferrous iron in a clear liquid state over deep geological time.
Moreover, continuous glacial movement creates immense physical pressure that forces the trapped subglacial brine into deep englacial fractures. These pressurized fractures form an active internal network that routes the iron-bearing brine straight toward the outer glacier face.
The pressurized brine erupts periodically through surface crevasses and pours over the stark white terminal ice cliff. Atmospheric oxygen immediately reacts with the suboxic liquid as soon as it vents into the open polar air.
Chemical oxidation rapidly transforms the soluble ferrous iron into insoluble ferric iron oxide minerals right before observers. This rapid rusting process stains the surrounding ice and forms a prominent red-orange frozen apron across the discharge zone.
Episodic outflow events add fresh layers of crimson deposits to the frozen apron during active discharge cycles. Warm summer meltwater subsequently transports a portion of these oxidized iron sediments directly into nearby Lake Bonney.
The Microscopic Discovery
According to Ken Livi, a research scientist at Johns Hopkins University, analysis using advanced transmission electron microscopes recently revealed an abundance of microscopic suspended particles within the red water samples. These tiny non-crystalline nanospheres contain high amounts of iron alongside silica, calcium, aluminum, and sodium.
The minuscule round nanospheres lack a regular crystalline lattice structure, which allowed them to evade detection in earlier studies. Standard X-ray diffraction tests failed to identify these amorphous nanospheres because researchers expected to find crystalline minerals.
Sunlight scatters off these dense iron-rich nanospheres as they oxidize, generating the vibrant crimson visual effect of Blood Falls. The presence of these oxidizing nanospheres fully explains why the clear underground liquid turns dark red so quickly.
Glacial pressure and subglacial hydrologic dynamics continuously drive this remarkable mineral-rich liquid to the surface of Taylor Glacier. Blood Falls stands as a dramatic example of subglacial chemical weathering creating a unique geological feature in Antarctica.
