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Earth Institute News

posted 03/03/01

Miles Below Antarctic Ice,
a Freshwater Lake May Harbor Ancient Life

By Robert Lee Hotz, L.A. Times Science Writer

Part 2: A Hidden Landscape

VOSTOK, ANTARCTICA-- Standing outside his tent, Studinger of New York's Lamont-Doherty observatory waves one gloved hand at the emptiness around him.

"We are right over the lake," he said. "The shoreline runs that way."

His humid breath crystallizes in icicles on his beard as he speaks. Bundled in a scarlet parka, he stands out like a tulip in the snow. It is 32 degrees below zero. The snow underfoot crunches like cornmeal on glass.

A few hundred yards away, a ski-equipped U.S. Air National Guard cargo plane thunders on idle as the camp's fieldworkers load canisters of trash and other waste aboard for recycling or disposal in the United States.

The austral summer air is so frigid that the air crew does not risk turning off the engines, in case the hydraulic fluid congeals or pistons become so chilled that they crack. It routinely gets cold enough for diesel fuel to freeze, for dripping oil to form icicles.

Nothing is visible on the surface of the East Antarctic Ice Sheet at Vostok, except thousands of square miles of wind-rippled snow. But two miles beneath this icecap is a freshwater lake as long as Lake Ontario and as deep as Lake Tahoe, its waters untouched for a million years or more.
© M. Studinger, 2001

There is nothing obvious at the surface to indicate anything of a lake, save a flatness so all-encompassing that it can be seen from space.

But after so many days poring over the chiaroscuro of seismic plots and radar readings, Studinger can easily see the contours of that hidden landscape in his mind's eye.

The lake is crescent shaped, with a steep escarpment almost 3,000 feet high along its northern shoreline and broad shoals to the south. As best anyone can tell, the lake is 124 miles long and covers 5,400 square miles. In its deepest basin, its waters are 3,200 feet deep.

The overlying tide of ice creeps across the lake surface so slowly that it takes 15,000 years for it to cross from shore to shore, sagging imperceptibly as it slides over the water, then buckling as it grounds on the opposite bank.

The lake water is cradled on a bed of sediments 229 feet thick, offering the possibility that they contain a unique record of the climate and life in Antarctica before the icecap formed.

In all there are at least 76 subglacial lakes in Antarctica. There is even a lake under the South Pole.

But not until 1996 — with the advent of advances in satellite surveying and radar studies — did anyone realize that the lake under the ice at Vostok was the biggest subglacial lake in the world and the largest geographic feature on Earth discovered in the past 100 years.

Like Lake Baikal in Siberia and Lake Malawi in East Africa, it may have formed in a rift valley created by the shifting of tectonic plates, according to geophysicist Robin Bell at the Lamont-Doherty Earth Observatory, who oversees the $4.5-million NSF mapping effort. Researchers have detected three moderate earthquakes in the area that seem to be evidence of tectonic activity.

"It is not a piece of old, quiet crust," said Bell. "It is a place where the Earth is moving."

If so, geothermal vents at the lake bottom could provide the heat and minerals to sustain life forms, just like the towering hydrothermal vents at the bottom of the Pacific Ocean.

It may be six months before Bell and Studinger finish their analysis of all the radar readings, seismic plots and gravity measurements they collected at Vostok.

Columbia University geophysicist Michael Studinger surveys Lake Vostok with a seismic sensor. © M. Studinger, 2001

The new map is a mosaic pieced together from systematic aerial surveys conducted by a chartered Twin Otter aircraft operated by the Support Office for Aerogeophysical Research (SOAR), an NSF-funded project at the University of Texas at Austin's Institute for Geophysics.

For people working out of small, isolated camps like Vostok in the interior of Antarctica, the twin-engined DeHavilland aircraft is a kind of aerial dog sled. On this mission, it carried a ton of radar, laser altimeter, gravity sensors and other geodetic gear.

The crew flew three flights a day, skimming for four hours at a stretch about 1,100 feet above the ice along a predetermined grid measuring 205 miles by 105 miles, explained SOAR operations manager Thomas Richter.

"The Twin Otter we fly is the only one like it in the world," said Richter. "No one else collects so much data or makes such a complete set of measurements simultaneously."

So thin and cold is the air at Vostok — at an altitude equivalent to 12,800 feet — that each stabbing breath holds only 60% of the oxygen in the air at sea level. The heart sprints. The mind numbs.

Some of the researchers slept with oxygen bottles. Most took pills to stave off altitude sickness. So arid is the atmosphere that they packed IV drip bags to ensure that no one became dangerously dehydrated.

Even so, four people were evacuated by aircraft when conditions became more than they could medically bear.

Life, children once were taught, is best lived in moderation.

And until recently, biologists focused their attention on those life forms that shared humanity's conservative taste for the temperate climatic and chemical conditions of middle Earth.

With that in mind, researchers long considered Antarctica's polar plateau, with its extreme cold, aridity and high levels of ultraviolet radiation, as sterile as an autoclave.

But now they realize that life is easily taken to extremes, in Antarctica and elsewhere.

Next: They're Everywhere >>

Copyright 2001 Los Angeles Times
Reprinted with Permission