Russian experts, leading to the drilling of the well subglacial lake Vostok in Antarctica, have resumed work, told RIA Novosti the head of the press service of the Arctic and Antarctic Research Institute of Hydromet (AARI) Sergei Lesenkov.
"Drilling has resumed after a short break for necessary maintenance work. We can not yet predict exactly when to leave the ice-water boundary, as there are several methods for the determination of the border, and they have all the precision of plus or minus 20 meters," — said Lesenkov.
Earlier it was reported that professionals need to clarify the diameter of the hole in the lower section and drilled it to continue.
Lake Vostok in Antarctica, concealed under a thick layer of ice chetyrehkilometrovoy is a unique aquatic ecosystem that is isolated from the earth's atmosphere and surface of the biosphere for millions of years. The study of ice cores from the well and the forthcoming study of the lake itself plays a huge role in building a natural scenario of climate change in the next millennium.
Ice Drilling was suspended at a depth of 3734-3738,5 meters. From 17 to 19 January employees of the research station measured the pressure of the drilling fluid and held caliper (measurements, in which a curve changes in the diameter of the borehole with depth). Furthermore, they conducted directional survey (determination of the spatial position of the borehole) and the sampled drilling fluid over the entire depth of the well.
Deep drilling at Vostok Station in Antarctica began in the 1970s, when the existence of the pond was not yet known, scientists were beginning to paleoclimatic research. In 1996, the Russian specialists with the assistance of British scientists discovered deep in the Antarctic ice lake, which is one of the largest freshwater bodies in the world. Subsequently, scientists have data about its size and shape, the thickness of the ice sheet, as well as the underwater topography and sediments by radio and seismic sounding.
In 1998, deep drilling has been suspended over the lake when the lake water before the relic was about 130 meters of ice. Then the international community has asked not to enter the water layer of the reservoir until the advent of the special technology that minimizes its possible contamination. This technology was developed in the St. Petersburg Mining Institute, and in 2003, during the 26th Consultative Meeting of the Antarctic Treaty, the international community agreed with the Russian proposals. Work on the deep drilling was resumed in 2005.
Seasonal work of the 57th Russian Antarctic Expedition (RAE) for drilling ice above Lake Vostok began Jan. 2, 2012. All works of this season will end on February 5, after touching the rig with the water column of the lake and a set of special operations. Then the experts will return to drilling only in December 2012 in order to obtain samples of fresh frozen waters of the lake, past the hole, and explore them.