U.S. scientists successfully drilled into Lake Whillans, a subglacial expanse of water hidden deep beneath the Antarctic ice sheet, they reported on Sunday (Jan. 27).
About a month ago, a similar British attempt to reach subglacial Lake Ellsworth had failed. Drilling operations for the WISSARD project (Whillans Ice Stream Subglacial Access Research Drilling), which is funded by the U.S. National Science Foundation's Office of Polar Programs, started on Jan. 21.
Over the next couple of days, equipment will be lowered down the 2,625-foot (800-meter)-deep hole to carry out measurements and to obtain water samples for further study on board container-based scientific laboratories on the surface. As of Sunday (Jan. 27), the WISSARD team said they may have penetrated the lake surface.
"Sensors on the hot water drill show a water pressure change, indicating that the borehole has connected with the lake," they write on the WISSARD blog. "Verification awaits visual images from a down-borehole camera this evening. We are excited about the latest developments at the lake!" (Photos: Subglacial Lake Whillans Drilling Site)
On Dec. 9, I visited the WISSARD test site on the Ross Ice Shelf, just off the coast of the Antarctic continent and close to McMurdo Station, as a selected member of the NSF Antarctic media visit program. The test site resembled a small factory, with generators, water tanks, labs, workshops, data centers and, of course, the actual drilling platform – all mounted on giant skis. In the background were the tractors that would pull the whole installation to Lake Whillans, across hundreds of miles of solid ice.
"This is a first go," said Ross Powell of the University of Northern Illinois, one of WISSARD's 13 principal investigators. "Next year we hope to return to drill more holes."
Frank Rack, a geologic oceanographer of the University of Nebraska who leads the WISSARD drill team, explained how a powerful jet of pressurized hot water is used to melt a hole in the ice.
"Our hot water drill is state-of-the-art," Rack said. Part of the system, including two 225-kilowatt generators and the power distribution modules, had previously been used to drill the holes for the IceCube Neutrino Observatory at the South Pole. The technique is simple in principle, but prone to unexpected problems. "My biggest worry is that something might get stuck," Powell said. With the successful completion of the actual drilling at Lake Whillans, this worry has now been laid to rest.
A big concern for the WISSARD team has been to prevent contamination of samples from the subglacial lake with microorganisms. After all, an important goal of the project is studying the lake's ecosystem, if it exists at all. Even at 195 degrees Fahrenheit (90 degrees Celsius) — the temperature the pressurized water for drilling is heated to — water contains a lot of spore-forming bacteria. That’s why the drilling hose is fed through a collar of ultraviolet lamps: the energetic radiation kills 99.9 percent of all microorganisms.
In contrast, the Russian team that drilled into subglacial Lake Vostok last year used kerosene to lubricate the borehole – a technique significantly less clean than hot-water-drilling.
Microbiologist Jill Mikucki of the University of Tennessee is pretty sure there might be life under the ice: microorganisms that are able to thrive in the cold, dark, isolated subglacial lakes. She doesn't expect to encounter larger organisms, because there's so little energy available at 2,625 feet (800 m) below the icecap, but "microbes are everywhere," Mikucki said. "There's even potential to find new species."
Subglacial microbes could accelerate weathering of rocks, Mikucki explained, releasing silicon and iron that finds its way into the ocean and serves as nutrients for other life forms. "I want to find out how they help to run the planet." (Antarctica Album: Stunning Photos of IceBridge Mission)