The landscape could be in upstate New York, western Maine, or any number of other scenic places: a few large lakes, many small ones, wide rivers and slow-flowing streams, water-filled hollows and soggy ground, all set in a stony land. But that’s where the resemblance to familiar landscapes ends. Here, no clouds float by, no rain falls, and no stars shine; there is no sunlight or moonshine, and no air at all. Instead, spread over this water-rich landscape, covering it almost completely and sealing it in, is 5 million square miles of glacial ice, roughly two miles thick and a million years old.
Image courtesy of Zina Deretsky NSF
This bizarre scene is found in Antarctica, the coldest place on Earth. If it were possible to lift up the giant ice sheets, that watery, stony terrain is what would remain. But of course it is not possible, so nobody knows what the buried landscape really looks like or how many living things may be down there. As of only a few decades ago, no one knew this world of buried lakes and rivers even existed. Now scientists are paying serious attention to it. Journalists have dubbed it “the last unexplored place on Earth” and “one of Earth’s last frontiers.” A veteran Russian glaciologist went so far as to call the discovery of one of Antarctica’s greatest subglacial lakes, Lake Vostok (now known to be the sixth-largest lake in the world, with a volume of about 1,300 cubic miles), “among the most important geographical discoveries of the second half of the 20th century.”
One thing that is known for sure about Antarctica’s network of subglacial waterways is that they are not some insignificant sideshow to the grand drama of the continent’s ice sheets. In fact, learning about the lakes and rivers could shed light (albeit from a very dark place) on weighty matters ranging from ice-sheet stability—how much do the lakes enhance the flow of ice toward the sea?—and the history of glaciation in Antarctica—did some lakes form before the ice?—to the continent’s contribution to rising sea levels. According to a recent National Research Council report, the discovery of subglacial lakes “opened an entirely new area of science in a short period of time.”
Taking advantage of that opening isn’t a whole lot easier than mounting an expedition with sled dogs and penguin stew. As the lakes are in remote, extremely cold locations and deeply buried, projects envisioned for studying them directly tend to be logistically challenging, time-consuming, and expensive. “It takes ages to get programs together,” says Mahlon Kennicutt II, an oceanographer at Texas A&M University and secretary of the Subglacial Antarctic Lake Environments group (SALE). There’s also a long period of environmental review required, largely because subglacial lakes have the potential to harbor life—and the life down there could very well be rare and exotic forms. Bacteria and other microbes that fell on the glacier surface would have spent a million years being carried downward as more snow fell above them before they eventually plopped into the lakes. There, in the near-freezing, totally dark, high-pressure, low-nutrient environment, some might have adapted in novel ways in order to survive. Studying these hardy microbes could provide scientists with clues to how life might exist on Mars or on Jupiter’s ice-covered moon Europa.
As yet, no one has touched the waters of a subglacial lake with so much as a drill bit, but a Russian group that has been coring ice over Lake Vostok to get ancient climate records is coming close. The Russians desperately want to be the first to reach a subglacial lake and sample it. “It is important to our country,” says Valery Lukin, an oceanographer and director of the Russian Antarctic Expedition. He compares reaching the lake to reaching the moon: “The U.S. made the first flight to the moon. They won. For our country it is very important to be first into a subglacial lake.” Russia has put a lot of national resources behind the effort and might be there by 2009. “It’s the centerpiece of their polar program,” Kennicutt points out.
Some scientists worry that the Russians’ drive to be first may put the pristine ecosystem in peril. Drilling equipment and fluid that is dumped down the borehole to keep it open may introduce microbial contaminants into the waters of the lake under the drill station (also called Vostok), making it impossible for scientists to know what was there naturally. John C. Priscu, a professor of land resources and environmental sciences at Montana State University who discovered microorganisms thriving in permanently frozen surface lakes in Antarctica at temperatures as low as –10 degrees Fahrenheit, wants to study microbes in Lake Vostok to learn if they are viable or unique, or both. “What is their lifestyle?” he asks. “Do they form a community? Do they eat each other? Do they make poisons?”
To answer these and other questions, he has to get to the Antarctic lakes before they become polluted.
Only a few decades ago, according to Priscu, most scientists still thought of Antarctica as Robert Falcon Scott did when he realized that he would be second at the South Pole: “Great God! This is an awful place.” The prevailing attitude was that Antarctica was a solid block of ice, Priscu says, a continent without life. The idea that there was water underneath either of Antarctica’s ice sheets (there is an eastern and a western one) seemed preposterous. “Water under ice sheets? Intuitively, it didn’t make sense to me,” Kennicutt admits. “It’s a very unusual phenomenon.” The first person to report evidence of a subglacial lake didn’t recognize what he was seeing. In 1958, a Russian airplane navigator named Robinson was making his landing approach at the newly opened Vostok research station when he noticed a large, flat, oval depression “with gentle shores” on the glacier surface. The smooth depression, we now understand, was a result of the bottom of the ice sheet floating free and frictionless as it passed over water instead of bedrock 21/2? miles below.
Then in the early 1970s, a team of British, American, and Danish scientists took airborne radio-echo soundings of the East Antarctic ice sheet to find out how thick it was, as part of an effort to determine the total mass of ice in Antarctica. In the process, they registered some flat, mirror-bright reflections above the bedrock, which they interpreted as “water pockets,” or small lakes at least three feet deep. (Radio waves don’t pass through water.) The scientists stressed the need for more study of the conditions at the bottom of the ice sheet because of a proposal published in the Bulletin of the Atomic Scientists in 1973 to use the ice sheet as a dumping ground for radioactive waste. (More God-what-an-awful-place thinking.) Since this newfound water might connect to the sea, the team argued, it could no longer be assumed that ice sheets are cut off from the “habitable world.”
