odditycentral.com - One of the most amazing sights in Antarctica, the Blood Falls have been a mystery ever since they were discovered, in 1911.
A bloody column of water coming out of a glacier isn’t what you’d expect to see in the frozen land of Antarctica, but if you visit Taylor Glacier, that’s exactly what you’re going to find. At first, scientists thought they were dealing with some sorts of red algae, but further research proved the bloody color was caused by something spectacular.
It turns out a small lake was sealed under Taylor Glacier roughly 2 million years ago. Incredible, isn’t it?!? Actually no, what’s incredible is the glacier acted like a natural time capsule for the ancient microbes living in the lake. These invisible forms of life have survived without oxygen, light or heat and are considered to be the “primordial ooze” out which every living thing on Earth evolved.
The Blood Falls are proof life can be found in the most extreme environments, probably even on other planets, like Mars.
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The Blood Falls of Antarctica
Blood Falls is an outflow of an iron oxide-tainted plume of saltwater, occurring at the tongue of the Taylor Glacier onto the ice-covered surface of West Lake Bonney in the Taylor Valley of the McMurdo Dry Valleys in Victoria Land, East Antarctica.
Iron-rich hypersaline water sporadically emerges from small fissures in the ice cascades. The saltwater source is a subglacial pool of unknown size overlain by about 400 meters of ice at several kilometers from its tiny outlet at Blood Falls.
Microbes have been living in dark pockets of an ancient saltwater lake trapped under the advancing Taylor Glacier in Antarctica between 2 million and 4 million years ago.
How did the microbes survived all that time without light, photosynthesis, or outside nutrients? Jill Mikucki, one of the researchers who reported the microbes’ existence in 2007, now reports on their unusual survival mechanism. In the current issue of Science, Dr. Mikucki and other researchers conclude that the microbes metabolize organic matter in the water by using sulphate to facilitate reduction of iron in the bedrock — the same iron that helps produce the rusty color of Blood Falls when the water from the subglacial pools reaches the snout of the glacier.
The microbes have been living in pools of brine beneath 400 meters of glacial ice, according to Dr. Mikucki, a research associate in the department of earth sciences at Dartmouth. I asked her to explain to Lab readers the chief significance of these discoveries. Her answer:
"Our work has demonstrated how microbes gain energy and grow below ice in the absence of sunlight for extended periods of time. Subglacial environments are difficult to access and therefore remain largely unexplored. The fact that we were able to describe how microbes can eke out a living below ice is rather interesting considering that we only recently realized life existed below glaciers.
When subglacial brine is actively discharged it provides a window into an ecosystem that has been cut off from the surface for possibly millions of years. The microbes have remained viable despite these extreme circumstances. There are also interesting implications to how life might have survived during past so-called ‘Snowball Earth’ events, of below the ice-caps of Mars or on Europa."
It appears that energy is obtained when sulfur is cycled through different oxidation states by reacting it with iron. The oxidized sulfur is then used to react with carbon compounds, powering the metabolism.
If it can survive below this glacier, why not below the ice cap on Mars and on Europa?
Sources:
http://www.nature.com/
http://tierneylab.blogs.nytimes.com/
http://en.wikipedia.org/
http://blogs.discovermagazine.com/
http://www.newscientist.com/
http://arstechnica.com/
Phantoms and Monsters
