Blood Falls Mystery Unraveled: The Science Behind Antarctica's Red Glacier
A series of scientific investigations, culminating in a recent study published in the journal Antarctic Science, has provided a comprehensive explanation for the distinctive red color and continuous flow of Blood Falls on the Taylor Glacier in eastern Antarctica. The research details the chemical and hydrological processes responsible for the phenomenon, including the nature of its color and the mechanism by which its briny water is expelled from a subglacial source.
Discovery and Initial Observations
Blood Falls, located on the snout of the Taylor Glacier in eastern Antarctica, was first documented in 1911 by geologist Thomas Griffith Taylor. The feature is characterized by a flow of iron-rich brine that is notable for its reddish hue, which does not derive from actual blood.
The Evolution of Color Explanation
Early scientific theories regarding the red color of the falls suggested it was caused by microalgae. This hypothesis was later superseded by the understanding that iron from a subterranean lake oxidized upon exposure to air, resulting in the reddish hue.
More recent research has further refined this explanation. It indicates that the iron responsible for the color is present in nanospheres. These iron particles are believed to have been formed or packaged by ancient, metal-metabolizing bacteria inhabiting a subglacial lake, with the iron originating from the lake bed. The water within this subglacial lake is also highly saline, which prevents it from freezing despite the glacial environment.
Mechanism of Water Expulsion
A study led by Peter Doran, a geoscientist at Louisiana State University, and his team, proposed a mechanism for how the water is continuously expelled from its subterranean source.
The research suggests that the weight and movement of the overlying glacier are responsible for driving the briny water to the surface.
The findings were based on a combination of research methodologies:
- GPS data analysis
- Visual time-lapse photography of Blood Falls
- Real-time temperature readings beneath the glacier
During an observed eruption of Blood Falls in 2018, instruments recorded several key events. Subglacial temperatures decreased, corresponding with changes in pressure. Concurrently, the glacier was measured to have dropped by less than an inch. This measured drop indicates that the pressure exerted by the glacier on the hidden briny water forces it through existing cracks in the ice, causing it to erupt and flow to the surface.