A thick water layer exists under Vostok Station

It was easy to write the word "re-examined" in our workshop report on a revision of seismic data at Vostok, but in reality there was some uncertainty about it as a result of past circumstances. Dr. Kapitsa mentioned publicly that he would do his best in this undertaking, but he also mentioned that he kept the Vostok seismograms in his personal scientific archive at his summer house (which had been partially destroyed in a major fire). We thought, knowing Murphy's Law, that the data would never be forthcoming. However, Lady Luck over-ruled, as she had in many other instances related to Lake Vostok, and Dr. Kapitsa located the Vostok seismograms.

Re-examination of the results of seismic reflections, which were acquired in 1964 at Vostok Station was completed in 1994 in Moscow and Cambridge some 30 years after the experiment. The results showed a very clear P-wave echo from the area of a second reflection, which together with some evidence of a sub-ice lake from radioecho sounding in this vicinity suggested a water depth of a little more than 500 m beneath the bottom of the ice sheet. This represented a final confirmation of the existence of the lake (Figure 3.2).

In 1994 at the XXIII Scientific Committee on Antarctic Research (SCAR) meeting, held in September in Rome, Dr. Kapitsa presented to various Working Groups of SCAR this new interpretation and the news of a 500 m thick layer of water beneath Vostok Station, thus impressing the delegates and guests at the meeting.

As a result of this discovery, Professor Kotlyakov, Russian delegate to SCAR, wished to draw the Lake phenomenon to the attention of SCAR because of its intrinsic scientific interest and its ramifications for the ongoing ice core drilling program at Vostok Station. He asked other delegates to express their opinions on an investigation of the phenomenon called "Lake Vostok'', informing them that this request was connected with the fact that the lake is located just below the Russian station and that for more than 25 years the Soviet (now Russian) expedition had been involved in deep-core drilling there. The depth of the borehole was more than

2,500 m at the time of the meeting, and the total thickness of the ice is 3,750 m. As a result of this discussion and of the Scott Polar Research Institute (SPRI) workshop report of November 1993 the SCAR delegates adopted "SCAR Recommendation XXIII-12" which was addressed to the Russian, French, and U.S. National Committees, the importance of which is evident in the following SCAR recommendation.

SCAR recommendation XXIII-12 concerning the reported subglacial lake beneath Vostok Station

Recognizing the extreme scientific value of the deep ice core drilling at Vostok Station; noting the reported existence of a subglacial lake beneath the drilling site; anticipating that the study of such a lake, possibly isolated from the atmosphere for a million years or more, would also have an extreme scientific value; concerned that such a lake not be inadvertently contaminated by drilling fluids, but at the same time recognizing that the present bottom of the drill hole is still about 1,000 m above the base of the ice sheet.

SCAR recommends to the Russian, French, and U.S. National Committees:

(1) that ice core drilling at Vostok Station proceed to the greatest depth that will still safely ensure undisturbed integrity of the reported lake;

(2) that drilling does not proceed beyond this point until there has been an environmental impact evaluation and relevant scientific investigations have been carried out; and

(3) that a workshop be held soon to consider all aspects of the situation.

The recommendation suggested to continue core drilling in the deep hole at Vostok Station, but mentioned the need for precautions against the penetration of the drilling equipment or a drilling fluid into the lake, or a contamination of the lake by any other means, before a special scientific investigation of this kind of question be completed, technical method of penetration be developed, and the required equipment manufactured.

Following informal consultations, it became apparent that Cambridge, U.K., would be the most suitable location for the proposed workshop. Dr. Heap, the Director of the SPRI at the time, said in his letter of 30 March 1995:

Following a suggestion from me, Professor Kotlyakov, Chairman of the Russian National Committee for SCAR, has agreed that the workshop recommended under SCAR XXIII-12 be held in Scott Polar Research Institute from 22-24 May 1995. Professor Miller, Chairman of the SCAR Working Group on Glaciology has agreed to be Chairman of the workshop. The workshop follows the informal meeting in Cambridge on 23 November 1993, which led to the new evaluation of data and to the support given in SCAR XXIII-12. The aim is for a workshop with around 15-20 experts representing a range of interests who can make authoritative statements and recommendations to the key National Committees and to SCAR as to the scientific merits of drilling through to the lake and its sediments. Since time is now short I have consulted Igor Zotikov, Gordon Robin, Vladimir Kotlyakov, Claude Lorius, Bob Rutford, and Peter Clarkson (Executive Secretary, SCAR) regarding who should be invited to the meeting ...

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