Questions… Enigmas… Mysteries… (6)
“Hidden Antarctic lake links to alien life”
Evelina Rioukhina, UNECE
This is the exact title taken from BBC News of 27 September 1999, when for the first time the fact of the discovery of the mysterious lake was officially released in the media.
Lake Vostok, this is how it is called, has a Russian name (word “Vostok” means East), although it has nothing in common with the territory of the Russian Federation because it is located almost in the center of the Antarctic. Or to be more precise, beneath the Antarctica, on the depth of 4,000 meters (four kilometres!) and immediately below the Russia’s Vostok Station, that is why the name Vostok was given to this newly-discovered lake.
In fact, the lake is indeed almost as big as Lake Ontario and twice as deep. Mysterious is absolutely the right word to describe this huge body of water. Lake Vostok is a large (10,000 /ten thousand!/ square km) at 77S, 105E. The lake is between 10 and 500 m deep, and is 280 (N-S) x 55 (E-W) km in size.
The first clues to Lake Vostok’s existence came in the 1970s, when British, U.S. and Danish researchers collected radar observations by flying over this region. The radar penetrates the ice and bounces off whatever sits below. When researchers found a surface as flat as a mirror, they surmised that a lake must exist underneath the ice. Gordon de A. Robin of the University of Cambridge reported the subglacial water, but the data didn’t reveal whether there was a single giant lake or several separate ones. Russians, travelling to the Vostok Station claim to be the one who initiate the theory on the existence of the Lake, however all these suggestions were not acted upon until 1996, when British and Russian scientists conducted airborne radar experiments. Their finding confirmed the existence of a huge lake under the ice glacier at a depth of over 3000 meters. The water in the lake is potentially several hundred million years old (different suggestions state different figures – from 15 million to 400 million years old).
Why was the lake liquid not frozen? Was there life in this lake? How would life survive in those temperatures? What would these organisms feed on? Could similar life forms exist on other planets in space, even our solar system?
All these questions remain without definite answers and studies of each of them raise more and more further questions.
No one knows how this lake stays liquid in a region which holds the uncomfortable distinction of having recorded the coldest temperature on Earth. Thermometers of the Vostok Station measured –89,6 C in July 1983, and the average temperature lowers down around –56 C. However, this is not the only lake, and since the discovery of Lake Vostok, 76 similar lakes have been found in Antarctica, one of which is under the South Pole.
The Lake Vostok and other more than 70 lakes deep beneath the polar plateau, are part of a large, sub-glacial environment that has been isolated from the atmosphere since Antarctica became covered with ice more than 15 million years ago. Scientists theorize that Lake Vostok probably existed before Antarctica became ice covered, and may contain evidence of conditions of the continent when the local climate was subtropical. The ice cap probably cut the lake off from the rest of the biosphere at least a million years ago – some researchers say 35 to 40 million years ago – and this could have provided a unique opportunity for life to develop along a separate evolutionary path.
Scientists have discovered a microbial world hidden deep beneath the
Antarctic ice. No one knows how any organism, cut off from air, sunlight
or any apparent source of life-sustaining energy, could survive in its
frigid currents or under such crushing pressure – more than 360
times the atmospheric pressure at sea level.
First discovery in this area belong to the Russians, who are very much involved because they are the only research station in the area. In fact, the Russian scientists have been working in this area within the ice-core drilling programme as part of a well recognised scientific glaciology study, which started in 1989, long before the discovery of the lake and had more possibilities to examine the ice core. S.S.Abyzov of the Russian Academy of Sciences in Moscow has found bacteria, yeasts, fungi, algae, and even pollen grains in the Vostok ice core going to depth of 2,750 meters, i.e. three quarters of the way to the bottom. Some of these organisms are alive and capable of growing, he reported. In 1998, the station was site of an international project to drill down into the ice just above the lake. This yielded the deepest ice core ever recovered, reaching a depth of 3,623 meters and at present scientists analyze this ice core, which is at this depth is formed from frozen lake water, and contains a sample of whatever was floating at the surface of the lake. The results of this analysis may indirectly indicate whether anything survives in the lightless body of water and will certainly help to learn more about how life can survive under extreme conditions on other planets on moons.
This last issue is a matter of particular interest to the UN space agency NASA. The agency is taking a close interest in Lake Vostok because it is keen to develop technologies that might help in the search for life on extraterrestrial worlds. Lake Vostok is thought to be a very good terrestrial analogue to the conditions on Europa, a moon of Jupiter which is thought to hold a large liquid ocean far beneath its frozen surface. If microbial life can exist in Vostok, then it also might thrive on Europa.
Currently the drilling works are interrupted because of the huge risk
of contamination by further drilling the way it has been done. No matter
what mysteries the lake keeps in itself, today the scientists are concerned
with the question on how can researchers study a place so unique and
delicate without contaminating or, even worse, destroying it? All possible
alternative to drilling methods are being examined, all possible methods
for studies and researches are still going on.
In 2000, for example in the Antarctic SOAR (Support Office for Aerogeophysical Research) flew the 36,4 hour mission over the Lake Vostok. Every second, instruments in the Twin Otter airplane measures gravitational attraction, radar reading, and 10 measures on a magnetometer. The results were astonishing; they may have found more mysteries that they solved, e.g. encompassing the southwest corner, they received indications, that the geological structure changed beneath the lake. Probably the biggest mystery is evidence of a huge magnetic anomaly.
Incidentally, the latest news, of July 2004, released by the Earth institute:
“Now, the most comprehensive measurements of the lake indicate that it is divided into two distinct basins that may have different water chemistry and biological characteristics. The finding have important implications for the diversity of any microbial life in Lake Vostok and for how scientists should study the lake’s various ecosystems, if an international scientific consensus is ever reached to explore the lake…
The scientists conclude that the arrangements of the two basins, their separation, and the characteristics of the meltwater may all have implications for the circulation of water within the lake. For example, it is possible that if the water in the lake were fresh, the meltwater in the northern basin would sink to the bottom of that basin, limiting the exchange of waters between the two basins. The meltwater in the adjacent basin would likely be different. The two lake basins could therefore have very different bottoms and very different biological and chemical compositions”.
One more, and definitely not the last, puzzle to be resolved.