Penetration of Lake Vostok

Lake Vostok has not been penetrated yet. Soon we will obtain samples of the water from the lake, investigate the water depth via remote systems, and discover their implications. Real experimental data on salinity and currents in the water of the lake, and data on biological materials, if found, might change some understanding of the phenomena of this remote and unknown part of the Antarctic Ice Sheet.

Legitimate questions exist regarding the penetration of the lake, namely why, where, and how? We already know the size of the lake, salinity of its water (most likely freshwater), and some information on its currents. The study of accreted lake water ice indicates that a number of types of bacteria in the lake are similar to those in the overlying ice cores. It might be better to not penetrate the lake at all, or defer the event (Roura, 1999), but if it is decided to proceed, there should be procedures established not only for the physical penetration of the lake but also to ensure that penetration leads to as little harm or impact as possible.

Deep-core drilling at Vostok Station was terminated at a depth that left only 130 m of ice between the bottom of the hole and Lake Vostok, and a team of experienced scientists with special equipment is presently preparing to go farther. Other teams of international scientists are planning devices for penetration of the lake or to study samples that will be retrieved. The time of penetration and sampling is imminent, with the results having a major significance for many aspects of science. It is not important whether it is the British, Americans, Russians or scientists from other countries who will be the first to penetrate the ice sheet and probe the lake, however, concepts of penetration and exploration of the lake are currently different in Russia when compared with other countries.

The "Russian concept" is based on more than 30 years of experience in core drilling, including microbiologically clean core drilling of deep boreholes at Vostok Station, resulting in a vast amount of experience that is vital for balancing the characteristics of the drilling equipment designed to survive in rigorous Antarctic conditions, and the demands to minimize contamination of the lake. This balance will be achieved even if some contamination of the lake might inevitably occur. It should also be mentioned that micro-organisms, which might enter the lake due to possible contamination from a borehole liquid and drilling device (in spite of its cleaning) would have a very small chance of survival in a medium that is foreign to them, a medium that is devoid of nutrients.

It is also clear that the experience of the sole team that has been working for more than 30 years on the issues of drilling to 3,620 m, with the borehole remaining open, at the only working station (for more than 45 years) in the vicinity of Lake Vostok, is critical to continuation of the drilling of the last few meters of ice remaining above the lake. The team concept in this case, consisting of scientists and engineers who have worked on these issues for many years, dictates that the same individuals and their cumulative knowledge are vital for the continuation and completion of the work.

Another concept is based on the possibilities of the penetration of Lake Vostok from another location, and not from Vostok Station. The resulting time involved in this proposal would lead to years of logistic preparations related to construction of a new manned station in Antarctica, and related deep drilling. This could lead to potential contamination of the lake by virtue of the introduction of hundreds of tons of equipment, fuel, drilling liquid, food, and a number of individuals that would occupy the site for many months, to say nothing of the millions of dollars spent to achieve goals that might result in the uncontrollable contamination of Lake Vostok water. Goals that are questionable could be solved by using the existing Vostok Station as a base for the final drilling of ice and exploration of the lake. In favor of the latter, a rule of science states that if it is possible to conduct an "experiment" (in a philosophical understanding of the word), it should be done as soon as possible if there is a scientific demand for it. The above discussion favors this demand, as shown by the scientists of many specialties who are awaiting samples of water from Lake Vostok.

The strategy of penetration into Lake Vostok was presented by the President of the Scientific Committee on Antarctic Research (SCAR), Professor Rutford, before participants of the SCAR International Workshop on Subglacial Lake Exploration in Cambridge, England, September 1999. Professor Rutford reminded the audience of the experience gained from other projects, especially from the Ross Ice Shelf Project (RISP). The majority of participants might not have taken the comments seriously, but I did because I took part in this project from 1974-1978, when Professor Rutford was the Director of RISP. The major objective of the project was to drill through the 416 m thick ice shelf to penetrate into the sea from a location known as the "J-9" Camp, located 500 km south of the ice shelf barrier. There was no information at that time on whether life might exist beneath the ice shelf far from the open ocean. A group of anonymous experts decided that requirements for the drilling equipment for penetration of the sea below the ice shelf should include an avoidance of any contamination of the subglacial environment beneath the bottom of the Ross Ice Shelf. As a result of these unrealistic requirements made by experts (some from fields of science not related to the issue at hand), the Americans produced very expensive and sophisticated equipment that was incapable of working in actual Antarctic conditions. As a result, the drilling equipment became frozen in the borehole and became unworkable at the beginning of drilling operations in the summer 1977 field season.

Drilling of the access hole through the ice shelf was completed the next season on 2 December 1977, but this time with a flame-jet, produced by the continuous combustion of fuel oil in a high-pressure air flow. The 416 m deep access hole with a diameter of more than half a meter flame-drilled its way to the sea below in 7 hours (Browning, 1978). But it also filled the hole with a large amount of a mixture of fuel oil and soot from the incomplete combustion of fuel oil. As a result a large amount of it escaped into the sea beneath the ice shelf. No one seriously considered the issue of contamination, but Mr. Hansen, a famous drilling equipment engineer and designer of the drilling equipment that froze in the borehole while attempting to make an ecologically clean hole through the ice shelf, mentioned to everyone at the camp that "If they had allowed me to put gallons of contamination under the ice shelf, I would design a completely different and much more reliable drilling unit, which would have never failed!" However, nobody listened to him: "Do not spoil the victory, Hansen..."

Was this article helpful?

0 0

Post a comment