Against the pleas of scientists and environmentalists, Russia is proceeding with plans to drill a giant lake locked under the Antarctic ice sheet, risking pollution in its first exposure to human contact. Lake Vostok, almost 13,000 square kilometres, has not been exposed to the outside world for hundreds of thousands of years. It is likely to contain unique life forms, and possibly fish.

Russian scientists have already drilled through 3650 metres of ice to come within 130 metres of the lakes surface, far inland in the Australian Antarctic Territory. Under the Antarctic Treaty, all territorial claims are suspended, enabling Russia to drill in the area claimed by Australia. Despite intense international opposition, the Russians plan to drill the final distance over the next two summers.

But the drill hole contains 65 tonnes of lubricating kero- sene and chemicals, a global Antarctic science conference in Hobart was told yesterday. "When you have drilled down four kilometres below the surface, its awfully high risk," John Priscu, a sub-group chairman of the Scientific Committee on Antarctic Research, said. Lake Vostok, discovered 10 years ago by aerial radio echo sounding, is more than twice the size of Lake Eyre. It lies below sea level and is believed to be up to one kilometre deep.

Dr Priscu, from the University of Montana, said microbes had been sampled from frozen lake water above the liquid surface. There were indications that it was heated geothermally and, like deep ocean vents, it could support life forms. "At these vents you can get tube worms metres high," he said. "With the evidence pointing to a geothermal source in Lake Vostok, you could probably get some pretty bizarre things. You could even have fish." Dr Priscu told the Antarctic research committee meeting that recent survey work showed that dozens of smaller lakes might lie downstream of Lake Vostok.

According to the Antarctic and Southern Oceans Coalition, these connections are another reason not to drill into the lake. Potential damage could spread to other linked subglacial lakes, the coalition told a recent meeting of Antarctic Treaty nations.

The coalition said: "There is a compelling reason to reassess all drilling activity. Lake Vostok is the seventh largest freshwater lake on Earth. Any risk to it through premature penetration is unacceptable." The Russian Governments Antarctic organisation reassured the treaty nations that it had found a way to prevent lubricating fluid from entering the lake.

It plans to leave enough of the fluid in the hole to prevent the thin shaft from closing, on the basis that the fluid will be pushed up by the pressure of the water below. Dr Priscu said the Russian Antarctic Expedition had cleared its proposal through the treatys environmental approvals system. But Coalition spokesman Alan Hemmings said the system had no capacity to veto the plan.
(Por Andrew Darby, The Age, 14/07/2006)