\nUsing a novel, helicopter-borne sensor to penetrate the surface of large swathes of terrain, a team of researchers supported by the National Science Foundation (NSF) has gathered compelling evidence that beneath Antarctica's ice-free...\nUsing a novel, helicopter-borne sensor to penetrate the surface of large swathes of terrain, a team of researchers supported by the National Science Foundation (NSF) has gathered compelling evidence that beneath Antarctica's ice-free McMurdo Dry Valleys lies a salty aquifer that may support previously unknown microbial ecosystems and retain evidence of ancient climate change.
An airborne electromagnetic (AEM) sensor, called SkyTEM, mounted to the helicopter, allowed the team to discover that brines--salty water--form extensive aquifers below glaciers, lakes and within permanently frozen soils. The brines may also play an important role in contemporary biological processes in the Dry Valleys.
\"These unfrozen materials appear to be relics of past surface ecosystems and our findings provide compelling evidence that they now provide deep subsurface habitats for microbial life despite extreme environmental conditions,\" says the study's lead author Jill Mikucki, an assistant professor of microbiology at the University of Tennessee Knoxville.
\"We believe the application of novel below-ground visualization technologies can not only reveal hidden microbial habitats, but can also provide insight on glacial dynamics and how Antarctica responds to climate change.\"
In addition to providing answers about the biological adaptations of previously unknown ecosystems that persist in the extreme cold and dark of the Antarctic winter, the new information could also help scientists to understand whether similar conditions might exist elsewhere in the solar system, specifically beneath the surface of Mars, which has similarities to the Dry Valleys.
The team also found evidence that brines flow towards the Antarctic coast from roughly 18 kilometers (11 miles) inland, eventually discharging into the Southern Ocean, a biologically rich body of water that encircles Antarctica It is possible that nutrients from microbial weathering in these deep brines influence near-shore biological productivity in that ocean. However, the vast majority of Antarctica's coastal margins remain unexplored. This new survey highlights the importance of these sensitive interfaces.
The research was published on April 28 in the open-access journal Nature Communications. Co-authors on the paper include researchers from the University of Tennessee, University of California-Santa Cruz, Dartmouth College, University of Illinois at Chicago, Louisiana State University, University of Wisconsin, Aarhus University in Denmark and Sorbonne Universites, UPMC University in France.
The NSF-funded researchers were part of an international, interdisciplinary team that used the AEM sensor, which was developed at Aarhus University in Denmark, to produce extensive imagery of the subsurface of the coldest, driest desert on our planet, the McMurdo Dry Valleys. Using a helicopter to make the observations allowed large areas of rugged terrain to be surveyed very efficiently.
The results shed new light on the history and evolution of the Dry Valley landscape, which, uniquely in the Antarctic is ice-free and which during the height of the southern summer has free flowing rivers and streams. The Dry Valleys also are home to briny lakes at the surface and beneath at least one of the glaciers that intrude into the Valleys.
Overall, the Dry valleys ecosystem--intensely cold, very dry, and home only to microscopic animal and plant life--closely resembles, during the Antarctic summer, conditions on the surface on Mars. In addition to many other studies, the Dry Valleys are home to projects that are investigating how climate has changed over geologic time.
The AEM team believes that the newly discovered brines harbor similar microbial communities persisting in the deep, cold dark aquifers.\n
![\"Discovery](\"https://static.lp.lexp.cloud/images/attachment_defaults/resource/large/missing.png\" "\\"Discovery")
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