Scientists First Glimpse Interior of an Antarctic Subglacial Lake

The CruxBy Guest BloggerJan 28, 2013 12:06 AM

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Science journalist Douglas Fox is in Antarctica on assignment for DISCOVER Magazine as the WISSARD Embedded Journalist.

Click to view photos from the drilling site.

Scientists have peered for the first time into the interior of a lake hidden beneath the Antarctic ice sheet. Subglacial Lake Whillans, located less than 400 miles from the South Pole, had sat isolated under the ice for hundreds of thousands of years—perhaps up to a million years. But over the last week a team of ice drillers has used a jet of hot water to melt a narrow hole into the lake through 2,600 feet of ice.

The WISSARD team celebrates successful deployment of the camera and probe down the 800-meter borehole. Final confirmation that the lake had been reached unfolded inside a steel shipping container parked on the ice sheet on four massive skis. Seventeen people crowded into this mobile control room as a video camera was lowered into the borehole. All eyes were riveted to a computer monitor. A scene reminiscent of cosmic wormhole travel unfolded on it: the camera steered into the black void at the center of the screen; the smooth, round, undulating walls of ice-hole scrolled by on the edges. Billowing clouds obscured the camera’s view in the lower reaches of the hole. Then, as the swirling silt settled, a fuzzy picture emerged: the camera lay on its side, its lens looking across a muddy brown bottom strewn with small rocks. Wisps of mud drifted above. The image, knitted in rows of grainy pixels, echoed the first pictures of the Martian surface, radioed back by the Viking lander almost 40 years ago. The door of the control room opened and in stepped a woman covered head to ankle in a sterile white Tyvek suit—Jill Mikucki, a microbiologist from the University of Tennessee in Knoxville who had helped lower the camera into the lake. Mikucki pointed her own little Canon at the image on the computer monitor and tried to snap a photo—“Oh,” she murmured, disappointed: the cold had killed her batteries. She paused. “It’s beautiful,” she said, forced to appreciate it in the moment—“really beautiful”—then she hurried out to help retrieve the camera. The drilling and exploration of subglacial lakes has garnered plenty of interest. Three of Antarctica’s subglacial lakes were due to be sampled this year by a trio of British, Russian, and American teams. But the endeavor has proven difficult. A highly regarded British team abandoned its attempt to drill into subglacial Lake Ellsworth shortly after Christmas, due to technical problems. The Russian team breached subglacial Lake Vostok last February: water gushed from the lake into the bottom of the 12,000-foot borehole, and then quickly froze due to the frigid temperature of the surrounding ice—as cold as -67° Fahrenheit in the upper parts of the hole. The first sample of ice from that hole was retrieved this month, and the Russians hope to analyze it later this year. The Lake Whillans drilling project (called WISSARD, and supported by the National Science Foundation) made its final approach into the lake with extreme caution. Drilling was paused 300 feet above the lake as the weekend began. Three to five thousand gallons of water were pumped out of the borehole to lower the pressure within, and drilling was slowed to a fraction of its former rate. As this occurred, Dennis Duling ducked in and out of the sled-mounted cargo container that serves at the drilling command room. The 61-year-old, with full white beard, battered Carhartt overalls, and radio clipped to his pocket, manages the seven-man ice drilling team from the University of Nebraska in Lincoln. “We don’t want to blast our way into the lake,” he said. Blasting in with too much pressure could have caused thousands of gallons of water to spill from the borehole into the lake—contaminating it before it was even sampled. In the end, things worked out well, though: pressure was higher in the lake than the borehole. As the break-in occurred, water gushed from the lake into the hole, raising its water level by 95 feet. The drilling of the hole represents only the beginning of the work. This narrow, 20-inch aperture into the subglacial world will gradually freeze shut over the next few days. Twenty researchers are now working round the clock to take advantage of this opportunity that they have waited years for.

Team members operate the "mother ship" which instruments are tethered to. A variety of instruments will be dropped into the lake—as many as time allows. Bottles lowered on cables will sample lake water. That water will be analyzed for dissolved minerals and living cells. Water currents will be measured. Sediment cores will be punched out of the lake floor; the layers of sand or mud could provide clues to the history of the lake—and perhaps, an idea of how long this spot has been covered by ice. The researchers will also scrutinize these sediments for microbes. If Lake Whillans contains life, then most of it will probably reside in the mud at the bottom of the lake: in this world devoid of sunlight and photosynthesizing plants, the ultimate source of energy will most likely be minerals, which bacteria chew on in the dark. Lake Whillans has already presented surprises. For one, the lake has turned out to be only five or six feet deep—shallower than the 20 to 30 feet that people expected based on seismic measurements. The original lakebed is probably 10 meters deep—“except that this lake is old enough to have filled with sediments for the most part,” says Slawek Tulaczyk, the glaciologist from the University of California in Santa Cruz who co-leads the project. Like many lakes in places like the Rocky or Sierra Nevada Mountains in the U.S., Lake Whillans was hollowed out by glaciers long ago—but then gradually filled with sediment that was washed in from upstream. That fine, wispy sediment may have been sufficiently waterlogged to register on the seismic measurements as water—“water too thick to drink and too thin to plow,” as John Priscu describes it. Priscu is a limnologist at Montana State University in Bozeman who co-leads the Whillans project with Tulaczyk and one other scientist.

Microbiologists prepare the first samples from the lake. Lake Whillans has already yielded some results: as the hot-water drill nozzle was first hoisted from the borehole 20 hours ago, a small amount of mud from the lakebed was swabbed from its metal cylinder. That mud, smeared out on slides and viewed under a microscope, revealed the clear glassy shells of diatoms: photosynthetic organisms that lived in West Antarctica at times when it was occupied by a shallow sea rather than an ice sheet. Most of these diatoms died and settled to the sea floor between 10 and 20 million years ago. Glaciers then tore them from their original resting places and pushed them downstream as the ice tilled up the earth during the dozens of glacial advances that have occurred since that time. Those diatoms are only a first glimpse—fortuitously salvaged from the drill. But Lake Whillans is also being sampled for present-day life. Those results are still to come.

See more stories and multimedia from Lake Whillans in this special report.

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