Antarctica’s creepiest landmark is teeming with life. According to a study published yesterday in Nature Communications, the so-called “Blood Falls” contain microbes living in extreme conditions unlike anywhere else on the planet.
Scientists have known for a while that life exists in lakes of liquid water frozen beneath Antarctica’s surface. For a long time, the falls’ eerie color was thought to come from red algae. But they weren't sure how extensive the waterways behind the red falls were. Now, a group of researchers have discovered that the iron-rich water oozing from under Taylor Glacier is just the mouth of a system of briny aquifers that sits more than 600 feet below ground, writes Colin Barras for New Scientist.
"We found, as expected, that there was something sourcing Blood Falls," lead author Jill Mickuki tells Rachael Feltman for the Washington Post. "We found that these brines were more widespread than previously thought. They appear to connect these surface lakes that appear separated on the ground. That means there's the potential for a much more extensive subsurface ecosystem, which I'm pretty jazzed about."
In order to find the source of the falls, Mickuki and her colleagues dangled an electromagnetic sensor from a helicopter to test the conductivity of the ground. When water freezes, it becomes more resistant to conducting electricity. But when Mickuki’s team flew the sensor over Taylor Glacier, they discovered large regions with low electrical resistance, writes Feltman. According to the study, this could point towards a large reservoir of salty groundwater hidden under the Antarctic permafrost.
"This may be the most different of all liquid water reservoirs on Earth since it is not directly replenished by infiltrating rainwater or seasonal snowmelt," Slawek Tulaczyk, one of the study’s co-authors, tells Barras of New Scientist. "It certainly is the least understood component of hydrological system on our planet, because it is hidden beneath either permafrost or the ice sheet."
Because the water beneath the glacier is twice as salty as seawater, it has a much lower freezing point. That means the waters that feed Blood Falls have the right conditions to support some hardy species of microbes. In fact, as Mickuki tells Feltman, these microbes could help scientists find life on other planets:
"The subsurface is actually pretty attractive when you think about life on other planets. It’s cold and dark and has all these strikes against it, but it’s protected from the harsh environment on the surface," Mikucki said.
Underground pockets of cold, briny water may be as good as it gets on planets like Mars, so these Antarctic microbes could help scientist discover where to look for new life forms.