Iron rich water, which could support microbial life, flows out of a glacier at Blood Falls in Antarctica. To gain more insights about the mysterious falls, scientists traced the water flowing underneath the Taylor Glacier, where it is located, leading to the discovery that salty water underlies much of Taylor Valley.
Brine is known to be released from the subsurface over Taylor Glacier's front. Microorganisms that feed on sulfur and iron come from these geological features known to be a hotspot of microbial life.
In a report published in the journal Nature Communications on April 28, the researchers revealed that the subsurface network connects the scattered lakes of the valley showing that they are not as isolated as once believed.
For their research, microbiologist Jill Mikucki, from the University of Tennessee, Knoxville, and colleagues mounted an electromagnetic sensor on a helicopter, which flew over Taylor Valley in Antarctica to test the conductivity of the ground below. The instrument produces a magnetic field that gathers conductivity differences in the ground to about 1,000 feet in depth.
The sensor's readings allowed the researchers to tell ice, from soil or something else such as liquid brine. Water, for instance, increases its resistivity when it freezes, which means that it is less conductive of electrical currents. Salty water, however, which can remain liquid at lower temperatures, has very low resistivity.
The researchers found water lying underneath Taylor Valley's icy soil and this water is twice as salty as seawater. Briny water was also found underneath Taylor Glacier.
"Regional-scale zones of low subsurface resistivity were detected that are inconsistent with the high resistivity of glacier ice or dry permafrost in this region," the researchers reported in their study. "We interpret these results as an indication that liquid, with sufficiently high solute content, exists at temperatures well below freezing and considered within the range suitable for microbial life."
The researchers said that there is the possibility that the extensive brine is not unique to the valley and that the subsurface ecosystems may be linked to visible lakes and possibly even interact with the ocean. The researchers said that their findings are relevant to planned missions on Mars.
"Scientists have been using the Dry Valleys to test instruments since the Viking missions," Mikucki said. "So how we detect the brines and access them is relevant to work on places like Mars."
Photo: German Aerospace Center DLR | Flickr
