ST. PETERSBURG, January 31, 6:50 /ITAR-TASS/. Russian researchers have suspended the drilling into Antarctica’s subglacial Lake Vostok at a depth of 3,172 metres just 57 metres from the point where ice meets water.
The pause is needed for replacing the cable in the drilling equipment, Valery Lukin, head of the Russian expedition, told ITAR-TASS. Once the cable has been reconnected to the drilling machine inside the well, work will resume.
Researchers will drill 47 meters and then stop ten metres from the surface of the relic lake. There will be no penetration into the lake this year, Lukin said, adding that this mission would be carried out by the next expedition.
Samples taken in the well have already been prepared for shipping to St. Petersburg’s Konstantinov Institute of Nuclear Physics, and some of them will be studied on the site.
One-third of the samples will join the collection of similar ice cores stored since 1968 and running for several kilometres. They were taken from five wells at the Vostok station and from wells at the Komsomolskaya station. The samples are stored in natural conditions so that researchers could study them at any time.
Lake Vostok was discovered geodetically by the 33rd Russian Antarctic Expedition in 1987. It lies under almost four kilometers of ice and is 250 km long and 50 km wide. The drilling started in 1989. On February 5, 2012, researchers reached the watershed at a depth of 3,769 metres and took the first samples of water, which contained traces of living organisms. However a year later water rose by 500 metres, and explorers had to drill a new well parallel to the old one.
The samples of water taken in the spring of 2013 were found to contain a new type of bacteria. St. Petersburg’s Arctic and Antarctic Research Institute told ITAR-TASS that the data were obtained by drilling through the ice to the subglacial lake using a technology that excludes its contact with the external environment.
Researchers obtained 54 metres of ice cores from depths ranging from 3,406 to 3,460 metres, including deep-frozen samples of water.
Russian scientists have already studied water samples taken in February 2012 and brought to St. Petersburg in May. New samples were taken in 2013 and were found to contain a group of bacteria or a living microorganism in the surface water of the subglacial lake.
More complex tests were conducted using purer samples that froze in the well drilled in the 2012-2013 field work season. They were brought to St. Petersburg and may contain unknown forms of microorganisms adapted to extreme conditions of the subglacial lake, which is the only earthly analogue of subglacial oceans on the ice-covered moons (Europa, Ganymede, Callisto) of Jupiter or (Enceladus) Saturn.
The head of the previous expedition’s winter team, Viktor Venderovich, said the lake located beneath four kilometres of ice “stands out in terms of huge size among more than 145 subglacial bodies of water discovered by way of radar probing in Antarctic.”
Venderovich believes that the project would help answer a key question about the existence of life in the lake that had not contacted with the atmosphere for millions of years. In his opinion, the emergence, development and current state of this unique lake are closely linked with the geological structure, the history of the climate and glaciation of the sixth continent.
“Extreme conditions in the subglacial lake characterised by high pressure, the absence of light, specific gas content of water and extremely scarce biological life make it an ideal experimenting ground for testing methods and technologies of searching for life on ice-covered planets and moons in the Solar System,” Venderovich said.
Alexander Frolov, deputy head of the Federal Service for Hydrometeorology and Environmental Monitoring, said earlier that the project would allow researchers to trace paleoclimatic changes half a million years back.
Geographer and glaciologist from the Russian Academy of Sciences Vladimir Kotlyakov believes that the lake was covered with ice 500,000 or 1,000,000 years ago.
The lake water is moving and has oxygen and other conditions necessary for living organisms. “As soon as we drill through the ice, we will find bacteria dating back 500 million years. Naturally, researchers do not know what kind of bacteria that could be. We must be very careful: this is very interesting but very dangerous,” he said.
Researchers have found anabiotic thermophilic bacteria (thermophilic DNA) in an ice sample retrieved from the depth of nearly four kilometres in the freshwater lake.
This species of microorganisms exist exclusively in temperatures exceeding 55 degrees Celsius. Meanwhile, air temperatures above subglacial Lake Vostok may drop to as low as minus 88.8 degrees.
“Warm streams from the earth entrails might have penetrated through cracks and formed the largest freshwater pond under the ice shield of Antarctica,” a researcher said. This theory will be either confirmed or dispelled by the upcoming taking of water samples from Vostok in 2008-2009.
“The water in the relic pond is twice as clean as double-distilled water,” the official said. Researchers have developed a unique method of penetration into the lake in order to keep it clean.
Experts estimate the age of the subglacial lake at 450,000 years. The lake is bigger than Lake Onega in Russia and its shape resembles Lake Baikal. The lake is 300 metres long, 30-80 metres wide, and one kilometre deep. The lake may hold over five million cubic meters of water.
The world scientific community considers Lake Vostok the last major geographical discovery of the 20th century.