Figures

1.1 Lake Vostok on the front page of Nature, June 1996 2

1.2 Map of the East Antarctic Ice Sheet 4

1.3 A large, hidden subglacial lake is mindful of Jules Verne's lake in Journey to the Centre of the Earth, where underground travelers find a lake containing sea monsters 5

1.4 Subglacial Lake Vostok as an analog of a sub-ice ocean on the Jovian moon Europa 6

2.1 (A) The thickness of the ice is equal to "the critical thickness'' corresponding to an ice bottom temperature equal to the ice melting temperature. (B) "Thin" ice, in which the bottom temperature is less than the ice freezing point. (C) "Thick"

ice, with a thickness larger than the critical thickness 10

2.2 Professor Zubov in 1955, when he wrote his papers on the critical thickness of Antarctic ice 11

2.3 Dr. Robin at the XIII Scientific Committee on Antarctic Research meeting at Jackson Hole, Wyoming, U.S.A. in 1974, at the time of his radio-echo sounding discovery of subglacial lakes 12

2.4 An oriented meteorite melting and the Antarctic Ice Sheet bottom melting analogy 14

2.5 Academician Treshnikov was instrumental in constructing Vostok Station just above Lake Vostok 15

2.6 Determination of an area of permanent bottom ice melting in the central part of the Antarctic Ice Sheet 17

2.7 Temperature profiles for an ice sheet at Vostok Station and Komsomolskaia Station 18

2.8 Dr. Zotikov in 1965 in the old South Pole Station library 20

2.9 Map of Antarctica showing regions of permanent ice melting at the bottom of the central part of the ice sheet 20

3.1 Dr. Kapitsa at the time he worked on the reinterpretation of his seismograms, taken at Vostok Station 24

3.2 Seismogram taken by Dr. Kapitsa at Vostok Station in 1964, reinterpreted by him in 1993, and presented to the SCAR meeting in 1994 25

3.3 American electrical drill unit at Byrd Station 27

4.1 Radio-echo sounding flight lines in Antarctica undertaken during 1967-1975 operations 32

4.2 Radio-echo sounding film showing a subglacial lake 33

4.3 A map of Dr. Robin's flights over Vostok Station 34

4.4 Locations of subglacial lakes as identified by radio-echo sounding 35

5.1 An isometric plot of Antarctica compiled from the ERS-1 satellite radar-altimeter data 40

5.2 Schematic representation of a subglacial lake in the central part of a thick, Antarctic-type ice sheet 41

5.3 Map showing the region of Lake Vostok as it was seen in 1993 43

7.1 The thermo-electric drilling device used to drill deep holes at Vostok Station . 54

7.2 Main deep-core drilling complex at Vostok Station 55

7.3 Electro-mechanical ice core drilling device KEMS 56

7.4 A change in temperature of the Antarctic Ice Sheet surface over the course of 420,000 years 58

7.5 Change in temperature and content of particulates in ice cores noted as a result of the study of the 3,330 m deep core from borehole 5G at Vostok Station. . . 58

7.6 Internal structure of the bottom part of the Antarctic Ice Sheet at Vostok Station as revealed by deep-core drilling 59

7.7 The housing for the microbiological deep-core drilling at Vostok Station . . . . 60

7.8 A device for sterile extraction of ice samples from the ice core station 61

7.9 Microflora of the ancient ice horizons below Vostok Station 62

7.10 Distribution of numbers of micro-organisms and dust particles along the length (age) of the Vostok Station ice core 64

7.11 Percentage of vital micro-organisms of different types decreasing with depth (and age) of the ice core 65

7.12 Bacterial cells in accreted ice taken from a lower part of the Vostok Station borehole 66

8.1 Lake Vostok seen as the relatively flat area of ice surface elevation contours . 70

8.2 An "A-scope" picture. A radio-echo sounding picture from an oscilloscope screen, taken above Lake Vostok showing a return radio-echo signal from the ice-water interface with coordinates of intensity of signal versus time when this signal returned 71

8.3 An "A-scope" picture. This picture shows a return radio-echo signal from the ice-bedrock interface 71

8.4 Example of radio-echo sounding through the ice sheet above Lake Vostok. . . 73

8.5 Subglacial Lake Vostok in surface elevation contours of 2-m intervals 74

8.6 Lake Vostok Ice Shelf in surface elevation contours of 2m 75

8.7 Thickness of floating ice from "A-scope" pictures plotted against surface elevation at locations clear of the boundary effects along and across the lake for flight number 130 76

8.8 First cross section of Lake Vostok presented by Dr. Zotikov for the second (1995) workshop on subglacial lake exploration 78

8.9 Cross section of a middle part of Lake Vostok along a line of the second part of flight number 130 79

8.10 Combined radio-echo sounding and seismic measurements along the long axes of Lake Vostok and two transverse profiles across the lake 81

8.11 Water circulation within Lake Vostok below the Lake Vostok Ice Shelf and above the still uncorrected lake bottom topography 83

9.1 Location of remote-sensing data in the Vostok area from 1959-2000 90

9.2 Over-snow radio-echo sounding and reflection seismic sounding investigations planned by the Polar Marine Geological Research Expedition as a part of the Russian Antarctic Expedition for 2000/2001 91

9.3 Location of the Lake Vostok Rift in the tectonic structure of Antarctica 92

9.4 Aerogeophysical investigations planned by the U.S. Antarctic Research Program (USARP) for 2000/2001 and the proposed area for investigation by the Polar Marine Geological Research Expedition (Russia) for subsequent years 93

10.1 Front page of the Washington, D.C., 1998, Lake Vostok Workshop, Final

Report 96

11.1 Diagram of the first step of the approach to enter Lake Vostok from the borehole at Vostok Station 104

11.2 Thermo-electrical drilling device for the initial entry into Lake Vostok 105

11.3 Penetration mechanism of thermo-electric drill 106

11.4 Coil tubing drilling technology proposed for fast access to Lake Vostok 117

11.5 Boreholes 5G and 5G-1 of Vostok Station 118

11.6 Cryobot of NASA's Jet Propulsion Laboratory (U.S.A.) 120

11.7 Nuclear powered SGARS, which would be capable of going from the surface of the Antarctic Ice Sheet to subglacial Lake Vostok 123

11.8 Mars Orbiter Laser Altimeter derived image of the northern Polar Cap of Mars 124

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