Poised for the plunge
WISSARD team ready to explore subglacial Lake Whillans
Posted January 14, 2013
The final push by a team of U.S. Antarctic Program (USAP) scientists to explore a lake nearly a kilometer below the ice sheet is about to begin.
Researchers were scheduled to start flying from McMurdo Station to the edge of the West Antarctic Ice Sheet this week. Their destination: subglacial Lake Whillans, a liquid body of water trapped under about 800 meters of ice. Their mission: To retrieve water and sediment samples from the lake to learn what sort of life might exist in such an extreme environment.
The exploration of the subglacial lake, one of nearly 400 now known to exist under Antarctica’s massive ice sheets, may also offer insight into how the water influences the movement of the glacial ice above. Lake Whillans is part of a regional subglacial waterworks that fills and drains periodically, eventually emptying into the Ross Sea under the Ross Ice Shelf.
Scientists also hope to learn some basic facts about the geology and chemistry of such a lightless aquatic system. In addition, the muck and mud below the lake floor could contain clues about the geologic history of Antarctica, as well as the ebb and flow of its ice sheets through time.
In other words, there’s a lot to learn from Lake Whillans.
And not a lot of time to do it.
After years of planning, instrument development and construction of a new hotwater drilling system, the scientists on the Whillans Ice Stream Subglacial Access Research Drilling (WISSARD) project may only have a few days to explore what many consider the last frontier in polar research.
It’s a lot of pressure. And quite exciting, according to Ross Powell, a professor at Northern Illinois University and one of the three scientists on the WISSARD executive committee. The project is mainly funded by the National Science Foundation’s Office of Polar Programs through the Antarctic Integrated Systems Science program.
“Thinking that we could be the first group to look at one of these things is certainly something that drives everybody. It certainly drives me,” Powell said a few hours before a modern-day wagon train of Case and Challenger tractors completed the two-week journey across the Ross Ice Shelf to the field site on Jan. 13.
The tractor traverse had just hauled some 18 containers of cargo, science labs and the hotwater drilling rig and platform across the Texas-sized ice shelf. They had left McMurdo shortly just before New Year’s Day following a series of tests of the drill and science equipment.
“I thought the test went really well. It was a good test because we found out where there were some problems, which we have now had time to solve. We are now set to go,” Powell said.
During December, the WISSARD team spent most of the month on the 60-meter-thick McMurdo Ice Shelf putting the drill and equipment through a dress rehearsal. It was the first time the entire operation had been put together in one place.
The complex hotwater drill system — designed, built and operated by the University of Nebraska-Lincoln — uses a combination of off-the-shelf components such as hot pressure washers, equipment salvaged from the IceCube Neutrino Observatory project at the South Pole, and some custom-made pieces. It will bore a 60-centimeter hole through the ice over Lake Whillans in about three days.
The choreography of the operation requires more than just sending a vertical parade of science instruments down the borehole to collect various water and sediment samples, as well as take scientific measurements. Water used by the drill must be filtered and equipment sanitized to ensure the pristine lake environment isn’t contaminated — or that biological samples aren’t somehow compromised.
Water entering the borehole will pass through a series of filtration modules. The hotwater drill equipment and science instruments will be treated to eliminate particles and microbes from reaching the lake water. Everything will pass through a UV collar around the mouth of the borehole for a zap of sterilizing radiation.
The clean access protocols are necessary but time-consuming, as the team discovered during the test phase.
“It certainly adds to the complexity and time of operations,” said Powell, one of about a dozen principal investigators on the project.
Of course, conducting research in Antarctica adds to the complexity of any operation. Weather will be the wildcard, as the scientists, hotwater drillers and support personnel will fly from McMurdo to the ice plain above Lake Whillans aboard ski-equipped aircraft. The field camp population may swell to more than 50 people if everyone is able to get in on schedule.
(As this story was being posted, weather had already delayed the first flights for two straight days. An advance team that was to work on a network of GPS receivers used to monitor the vertical movement of the ice was also delayed repeatedly the week before.)
Project personnel have met daily — often several times a day — at McMurdo Station’s Crary Lab, as plans are refined and revised to maximize the science in response to the ever-changing conditions and challenges.
“I’m really impressed. They’re really delving into the details to make it work,” said Susan Kelly, the project’s education and outreach coordinator who manages the WISSARD website and social media platforms like Facebook.
The very best case scenario calls for a week of round-the-clock science operations. The team is braced for the possibility that they could end up with just one manic day to retrieve samples from the lake. Returning with one liter of water and one meter of lake sediment cores would be considered a success under those circumstances.
“All of that is weather dependent,” Powell emphasized, noting that the entire operation will shut down at the end of the month.
The deadline itself is based on the tractor traverse timeline: The drivers and their vehicles must drive back across the Ross Ice Shelf before mid-February. That’s when the summer field season at McMurdo Station winds down and intracontinental flight operations cease, meaning no air support in case of an emergency.
Whatever the schedule, the WISSARD team, aside from hard samples, is also keen to send another key piece of equipment into the lake during the limited amount of time. The Micro-Submersible Lake Exploration Device (MSLED) is a slim submersible designed by collaborator Alberto Behar at NASA’s Jet Propulsion Laboratory (JPL). MSLED sports chemical sensors and a high-resolution imaging system to scope out the environment below the ice.
“You can learn a lot just by observing. Just having a visual from MSLED’s camera will represent new data,” Powell noted.
The 2012-13 summer field season marks something of a new era for subglacial research, with three projects under way.
An effort by the British Antarctic Survey (BAS) this season to reach subglacial Lake Ellsworth ended on Christmas Day when the hotwater drilling operation failed to bore through the ice properly, seeping into the porous upper layers of the ice sheet. The project had been delayed previously following an equipment failure with a boiler used to heat the water for drilling.
Meanwhile, Russia’s Arctic and Antarctic Research Institute announced Jan. 10 that its scientists had obtained the first sample of transparent ice from the water of Lake Vostok, the largest subglacial lake in Antarctica.
While all three projects are studying subglacial lakes, the environments are quite dissimilar. Lake Vostok is believed to have been isolated for millions of years. Lake Ellsworth may have occupied an ancient fjord for hundreds of thousands of years. Meanwhile, the periodic draining and filling of Lake Whillans represents an entirely different subglacial paradigm than the others do.
It took the Russians decades to punch their way down into Vostok. The British are discouraged but not defeated, as Martin Siegert, principal investigator of the BAS experiment, vowed, “I remain confident that we will unlock the secrets of Lake Ellsworth in coming seasons.”
Now the Americans are itching for their chance.
“This is an incredible opportunity that was only made possible by the hard work of so many people from the USAP community,” said Jill Mikucki, an assistant professor at the University of Tennessee, Knoxville, and principal investigator on the biological component of the project.
“You can plan, as we have, for years to make a vision of a project into reality — but to actually be here, in McMurdo, and see the pieces coming together from logistics, science and drilling — it is extremely exciting,” she said.
The biologists will perform some of their initial analyses at the field site from two labs specially built for WISSARD. The possible discovery of microorganisms in the water or sediment would represent the first finds from such a subglacial environment.
“There are some things that we may know fairly quickly on site, while other measurements will take some time to fully analyze,” Mikucki said.
The WISSARD team certainly understands the lofty expectations of the science community in these nascent days of subglacial research. However, they are also motivated by a very human desire.
“The main thing on our minds is to get it done for ourselves. We’ve put so much time and effort getting to this point,” Powell said. “We’re excited.”
NSF-funded research in this story: John Priscu, Mark Skidmore and Andrew Mitchel, Montana State University, Award No. 0838933; Slawek Tulaczyk, University of California-Santa Cruz, Award Nos. 0839142, 0838947; Ross Powell and Reed Scherer, Northern Illinois University, Award Nos. 0839107, 0839059; Ross Virginia and Jill Mikucki, Dartmouth College, Award No. 0838896; Brent Christner, Louisiana State University, Award No. 0838941; Jeffrey Severinghaus and Helen Fricker, University of California-San Diego Scripps Institution of Oceanography, Award No. 0838885; Robert Jacobel, Saint Olaf College, Award Nos. 0838855, 0838854; Sridhar Anandakrishnan, Pennsylvania State University, Award No. 0838763, 0838764; Susan Schwartz, Andrew Fisher and Slawek Tulaczyk, University of California-Santa Cruz, Award No. 1043784; and Alberto Behar, Arizona State University, Award No. 1142123.
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