Saturday, February 16, 2013


Blood Falls certainly looks like a waterfall of blood, but blood is not the source. The waterfall is an outflow of an iron oxide-tainted plume of saltwater, originating at the tongue of the Taylor Glacier cascading into West Lake Bonney, found in Taylor Valley, McMurdo Dry Valleys in Victoria Land, East Antarctica. The deposit was discovered by the Australian geologist Griffith Taylor in 1911, for whom the valley is named.

Initially the red colour was attributed to red algae, however the water which feeds Blood Falls is iron-rich hypersaline water, coming from small fissures in the ice cascades. The source of the saltwater is a subglacial pool beneath 400 metres of ice, several kilometres away from Blood Falls. This water is the last remnant of an ancient salt-water lake, around five kilometres across. The lake probably formed as much as 5 million years ago when the sea levels were higher and the ocean reached far inland.

Within this ice-sealed salt-water lake is an ancient community of microbes. Researchers believe that, as there was not enough light to make food through photosynthesis, and with little heat, the microbes underneath the ice adapted over the past 1.5 million years to manipulate sulfur and iron compounds to survive. This kind of process had never been seen in nature before. According to researchers at Dartmouth College, water samples from Blood Falls contain at least 17 different types of microbes, and almost no oxygen.

This amazing system has implications for astrobiology. Scientists have an opportunity to observe deep surface microbial life in extreme conditions without needing to drill deep boreholes and risk the associated contamination. This in turn helps scientists to understand the range of conditions within which life can survive; leading to further speculation of the environments in which we could find life elsewhere in the Solar System.
Photo: Peter Rejcek, National Science Foundation

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