Formation. Of clathrate hydrates of hydrochlorofluorocarbon 141b in the deep borehole at Vostok. Station (Antarctica) in the course of the unsealing of subglacial Lake Vostok.

The subglacial Lake Vostok in Antarctic is a unique natural phenomenon, its comprehensive study involves sampling of water and bottom surface rocks. For further study of the lake, it is necessary to drill a new access well and develop environmentally safe technologies for its exploration. This article discusses existing and potential technologies for sampling bottom surface rocks of subglacial lakes. All these technologies meet environmental safety requirements and are conducive for sampling. The authors have proposed an alternative technology, using a walking device, which, due to its mobility, enables selective sampling of rocks across a large area from a single access well. The principal issues, related to the implementation of the proposed technology, are investigated within this article. This report is prepared by a team of specialists with many years of experience in drilling at the Vostok Station in Antarctic and in experimental work on the design of equipment and non-standard means of mechanization for complicated mining, geological and climatic conditions.

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Characterization of subglacial Lake Vostok as seen from physical and isotope properties of accreted ice

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2014.0303 ◽

2016 ◽

Vol 374 (2059) ◽

pp. 20140303 ◽

Cited By ~ 8

Author(s):

Vladimir Ya. Lipenkov ◽

Alexey A. Ekaykin ◽

Ekaterina V. Polyakova ◽

Dominique Raynaud

Keyword(s):

Lake Water ◽

Hydrological Regime ◽

Gas Content ◽

Deep Drilling ◽

Lake Vostok ◽

Subglacial Lake ◽

Direct Sampling ◽

Vostok Station ◽

Different Depths

Deep drilling at the Vostok Station has reached the surface of subglacial Lake Vostok (LV) twice—in February 2012 and January 2015. As a result, three replicate cores from boreholes 5G-1, 5G-2 and 5G-3 became available for detailed and revalidation analyses of the 230 m thickness of the accreted ice, down to its contact with water at 3769 m below the surface. The study reveals that the concentration of gases in the lake water beneath Vostok is unexpectedly low. A clear signature of the melt water in the surface layer of the lake, which is subject to refreezing on the icy ceiling of LV, has been discerned in the three different properties of the accreted ice: the ice texture, the isotopic and the gas content of the ice. These sets of data indicate in concert that poor mixing of the melt (and hydrothermal) water with the resident lake water and pronounced spatial and/or temporal variability of local hydrological conditions are likely to be the characteristics of the southern end of the lake. The latter implies that the surface water may be not representative enough to study LV's behaviour, and that direct sampling of the lake at different depths is needed in order to move ahead with our understanding of the lake's hydrological regime.

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