March 16, 2015
What’s in Antarctica’s Blood Falls?
Caused by the leakage of iron-oxide brine, Blood Falls is a five-story tall Antarctic phenomenon that literally looks like a bleeding glacier.An international team of researchers recently tapped into the source of that brine, a reservoir that has sat there for millennia, and is currently set to begin testing the samples they extracted.
More than just a super salty chemical soup, the brine from Blood Falls is known to contain extremeophiles, or microorganisms adapted to the extreme cold and harsh chemical nature of the environs beneath an Antarctic ice sheet.
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A previous effort in 2004 gathered samples from the mouth of the falls and found an active microbial community. The main problem with this study is that the organisms had been exposed to the relatively less hostile conditions of Antarctic air and water.
The new effort attempted to circumvent this problem by tapping into the direct source of “blood,” a reservoir located up the glacier and deep underneath it. As is typically the case when drawing blood, the international team used a massive syringe-like device called the IceMole to burrow through the glacier and extract their samples. In order to locate the precise location of brine, the team bored holes down and then plunged thermometers into the ice.
According to Slawek Tulaczyk, an earth sciences professor at the University of California Santa Cruz, the extraction of brine from Blood Falls was unlike anything done before.
“The two tools which have proven to be the most useful in this process were the ground penetrating radar (GPR) and measurements of ice temperature in shallow boreholes drilled to 30-40 feet below glacier surface,” Tulaczyk told redOrbit via email.
He noted that a group headed up by Erin Pettit, from the University of Alaska Fairbanks, was in charge of collecting the GPR data.
“They collected a dense grid of data by running around the glacier with dozens of pounds of equipment and odd-shaped antennas strapped to them,” Tulaczyk said. “Because much of the area is very steep, and ice is slippery, they often had to be roped up and connected to safety anchors as they worked on ice slopes as steep as 45 degrees.”
To confirm the presence of brine, the team used temperature probes to detect the 23-degree F brine underneath the -2.2-degree F glacier.
“Thanks to this combination of geophysical techniques, and to our hard work, we have identified where the IceMole should go to look for brine within the glacier and we have now an amazing dataset, which demonstrates that liquid water can survive transit through extremely cold glacier ice,” Tulaczyk said.
A cold, dark, and salty community
Team member Jill Mikucki, a microbiologist at the University of Tennessee Knoxville, recently told redOrbit that her studies of this unique microbial community could take any number of turns as her team isn’t quite sure of exactly what they’re going to find.
“You could ask some preliminary questions and get some answers, like what is the diversity of organisms present in the sample, but then you can also delve deeper into it and spend more time with the data,” Mikucki said.
The Tennessee microbiologist said the peer-review process prevents her from talking about her expectations, but said her investigations will be focused on extremeophiles that are uniquely adapted to this environment under the Antarctic ice sheet.
“What I would hypothesize… is that, we’re looking at a community that is adapted to the conditions in Blood Falls, which is cold, dark and salty,” she added. “So, I would expect organisms that to us are extreme, but have unique capabilities to grow and deal with these kinds of conditions. That’s the kinds of questions we’ll be asking of these samples.”
Mikucki said the brine they will be studying is more concentrated than sea water, but with chemical similarities.
“The preliminary analyses that we’ve done so far seems to suggest that, yes it is related to marine salts,” she said.
A glimpse of Earth's marine past
To investigate the brine, Mikucki’s team and her international collaborators will use geochemistry techniques to analyze the various chemical species, cultivation work to grow microbial species for a range of research possibilities, and molecular tools to explore the DNA and nucleic acids of these microorganisms and how their genetic material helps with survival.
Mikucki also noted that the Blood Falls brine does seem to have its origins in the ocean and said the upcoming research could provide a glimpse of Earth’s marine past.
“It does provide a snapshot back into time, when you start to ask questions like ‘How did this brine get there in the first place and what was this area of Antarctic like at the time that these marine waters were there?’” she said. “These are questions that can tell me something about change in the Antarctic region over time due to climate change and things of that nature.”
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“So it is provide clues about the past,” Mikucki continued. “At the same time, there appears to be a modern ecosystem operating within that historical framework.”
Tulaczyk added that the results of the study could have applications beyond Earth.
“Blood Falls demonstrates that even on really cold planetary surface, liquid water can come to, or near, surface where we may be able to send rovers to look for life,” he said.