"A 'small window' to the unknown world of subglacial Lake Vostok is open," wrote Valerii Lukin, head of the Russian Antarctic Expedition, in a press statement sent to Discovery News today. Details on the Russian drilling expedition in Lake Vostok clarify that no melt drill was used during the last part of the procedure and 1.5 meters cubed (53 cubic ft) of drilling fluids, kerosene and freon, poured out of the top of the borehole as the lake water pushed its way into the hole from the bottom at 3769.3 meters (2.34 miles) deep:
The event at the inland Antarctic station Vostok waiting for which kept in suspense the international scientific community and many mass media in this country and abroad for the few past months has happened at last on 5 February at 20.25 Moscow time. Penetration to relict water of subglacial Lake Vostok through the deep ice borehole 5G was performed by drillers of the glacial-drilling team of the 57th Russian Antarctic Expedition. The day before on 4 February there was a contact of the drill with the water lens at the borehole depth of 3766 m. The ice core bottom segment extracted from this depth served as evidence – the surface of the lower 70 cm of the ice core was glazed, as if it were submerged to water just before recovery. No ducts or capillaries in the ice core body were visually observed at this. Exactly this contact with the water lens in the borehole was erroneously interpreted by some mass media as a real penetration to the lake water layer.
Indicating that whatever water was in the bore hole at that time - yes - it likely came from the lake, still the drill itself had not penetrated the lake's surface water - yet.
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The next launch of the drill to the borehole bottom showed the drilling process to stop. The drill pump intended for pumping away the drilling fluid with the ice slime from the boring bit cutters, began pumping water to the inner space of the drill. As it turned out, during the next drill rise, about 30-40 liters of water, frozen in the process of recovery, was lifted to the drilling complex. We remind that the constant ice sheet temperature in its upper part at Vostok station is -55° С. Samples of “fresh frozen” water were collected to special sterile laboratory vessels.
Until just then, the ice cores around this depth coming out of the drill hole were more than 420,000 years old. That kind of ice is very distinctive. Just touching it can lead it to pop and crack like a crispy treat as it undergoes changes in pressure. "Freshly frozen" ice is like a slurpy stuck together. It was another sign that they were close, that the lake water was pushing its way into the hole as they were drilling it.
Drilling of the ice sheet was continued after this operation and the next day the drill contact with the real water body of subglacial lake occurred at a mark of 3769.3 m. Sensors have registered a sharp increase of pressure at the bottom and of the thrust moment at rotation of the drill boring bit. After this N.I. Vasilyev, Head of the team and Zubkov V.M., lead engineer-driller, who were at this time on the watch, began to urgently recover the drill to the surface. As envisaged by the technology of environmentally clean penetration to subglacial Lake Vostok developed in 2000 at the St. Petersburg State Mining Institute and the Arctic and Antarctic Research Institute, the water rise from the lake in the near-bottom part of the borehole occurred at a height of about 30-40 m from the lower surface of the ice sheet. The drilling fluid consisting of a mixture of kerosene and Freon, which is less dense than lake water, began to rapidly rise along the borehole. As a result, about 1.5 m3 of this fluid poured out through the upper surface of the borehole to special trays, installed in the drilling complex and was then pumped out to the barrels. So the results theoretically predicted 11 years ago, were fully proved in practice.
And there you have it - the world's first Antarctic subglacial geyser.
ANALYSIS: They Did It! Russians Expose Lake Vostok Secrets
An artist's cross-section of Lake Vostok, the largest known subglacial lake in Antarctica. Liquid water is thought to take thousands of years to pass through the lake, which is the size of North America's Lake Ontario. (Nicolle Rager-Fuller,NSF)
Tags: Antarctica, Engineering, Polar Regions
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