It was a heartbreaking Christmas Eve for the British Antarctic Survey (BAS). A BAS team had arrived in western Antarctica earlier this month, preparing for its highly anticipated mission to drill into a long-buried subglacial lake known as Lake Ellsworth. But after days of hard labor, the team announced today that it was pulling the plug on its mission, stymied by an insurmountable technical problem.
"Our Christmas day was pretty bleak," says Martin Siegert, principal investigator of BAS's Subglacial Lake Ellsworth experiment. "We're really disappointed."
The team was one of three groups in Antarctica using cutting-edge technology to attempt to penetrate one of the continent's more than 360 subglacial lakes this austral summer. All hoped to find evidence of living organisms in the subglacial environment. Siegert's team planned to use hot-water drilling through 3 kilometers of ice to minimize potential contamination of the lake -- a technique that has been used before by Antarctic scientists, but never to drill so deeply. Even if everything went according to plan, the team would have had just 60 hours to collect water and sediment samples from the lake before the borehole would refreeze.
The project started out well. The technology requires vast amounts of water, and for 10 hours, the team used hot water to melt a borehole from the surface of the ice down to about 300 meters. At that depth (where the ice is hard and packed, and no longer porous), they created a reservoir of water. About 2 meters away from the original borehole, the team drilled a second borehole, hoping to connect it to the reservoir, too. The next step would have been to complete the drilling of the original borehole down to 3 kilometers, completing a looped system. The reservoir at 300 meters depth would replenish water at the surface that's used for the drilling, and would also help the team equilibrate the pressure between the lake and the borehole.
The trouble came when the team tried to connect the second borehole to the reservoir. For 40 hours, without rest, they drilled and kept the reservoir liquid, hoping to make the connection—and consuming much of the fuel they had brought with them. But they never located it. "We got to a situation where we did a calculation of how much fuel we needed to get down to the lake," Siegert says. "And we realized we didn't have enough anymore."
Facing that grim reality, the team called it quits—and although the initial mood was dark, Siegert says, "we've been warmed by the levels of public interest in the program, and the amount of support." Now, the team is regrouping, trying to learn lessons from this season. Realistically, he says, they aren't likely to get back to Lake Ellsworth in less than 4 years, and more likely 5. Given the small windows to do work in Antarctica, it may take a couple of years just to retrieve all the equipment and return it to the United Kingdom for modifications. And they will need to solve the mystery of what went wrong—why they couldn't find that reservoir -- and engineering a solution before the team is ready to try again.
"It's really the cutting edge of science, the work we're trying to do—it's stuff that no one's ever done before," Siegert says. "When you do have a technical failure, you shouldn't regard the research as being failed. It's part of a learning curve." And after a few days of despondency, he adds, "We're looking forward to having a bit of a holiday and a break. It's been quite intense."