Today, the fringes of this great white wilderness are valued by scientists as a store of unique wildlife, and its heart is prized as a precious barometer of Earth's fevers and chills.

By digging deep -- two miles (more than three kilometers) deep -- into the crust of ice that blankets the world's least hospitable continent, this rotating commune of French and Italian researchers is tracing the history of the planet's climate going back nearly a million years.

Getting the samples is a straightforward if technically daunting procedure. Using three-meter (10-feet) lengths of 9.8-centimetre (4.4-inch) -diameter aluminium tubing, the scientists drilled in increments, preserving samples to be analysed in laboratories on site and in France or Italy. Particles of dust and air bubbles trapped in the ice make it possible to establish links between the presence of greenhouse gases in the atmosphere -- especially carbon dioxide (CO2) -- and shifts in weather patterns across the millennia.

"It's of huge importance for understanding the climate machine," says Dominique Raymond of the Laboratory for Glaciology and Environmental Geophysics (LGGE), based in Grenoble, southeastern France.

These invisible signatures in the ice can reveal the atmospheric nuclear tests of the 1940s, 50s and 60s as well as the eruption of Krakatoa in 1883 -- and other climate events that go far beyond the brief history of Homo sapiens.

The data will yield "a succession of hot and cold cycles" going back 875,000 years, the first time such an ancient record has been established, explained Olivier Cattani, a glaciologist from the Climate Science and Environment Laboratory in Saclay outside Paris.

It took researchers nearly 10 years to drill through 3,270 metres (10,627 feet) of ice to within five metres (16.25 feet) of bedrock. "At Concordia, the deep glaciology is finished," he said. "But the science is just beginning."

The results from studies here and other research centers at both extremities of the planet are set to confirm that CO2 levels are higher now than at any time in the last 800,000 years.

Significantly, Cattani said, the measurements have shown only a meagre difference, of around 8 C (14.4 F), between the last warm period (the Holocene, our present era) and the last ice age, some 21,000 years ago.

The 500-odd scientists in Paris comprising UN Intergovernmental Panel on Climate Change (IPCC) will release a report on Friday that will summarize the most recent research and predict temperature rises over the next century.

In its last report in 2001, the body forecast that by 2100 the global atmospheric temperature will have risen between 1.4 and 5.8 C (2.52-10.4 F) compared to their 1990 level, depending on how much greenhouse gas is emitted.

The French first set up a scientific base at Concordia, some 1,100 kilometers (700 miles) inland toward the South Pole from the Indian Ocean, in 1992, and were soon joined by Italy. In 1996, under the auspices of European Project for Ice Coring in Antarctica (EPICA), they established the year-round habitat Dome C, and began digging into the ice plateau. In the summer months of November through March, when temperatures hit a balmy -30 C (-22 F), the station -- a pair of snow-white three-story cylinders connected by a passageway along with several technical structures -- can accommodate more than 30 scientists and staff.

But the PhDs can only reach the base by an arduous voyage, through wave-tossed, iceberg-infested seas, aboard the supply ship Astrolabe, and then overland by helicopter and snow tractor.

In winter -- with average thermometer readings of -60 C (-76 F) -- the population plummets to 16 or fewer.

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