It was August 16th 1897, a beautiful summer day, a day like any other for most people, but nevertheless a special day for a team of nineteen men, who had long prepared themselves for that moment. The harbour was crowded and bustling with activity, because the ship “Belgica” was about to set sail from Antwerp, accompanied by the tunes of a brass band, and head towards the Antarctica. The crewmen readied themselves as well as they could for such an experience: maps and plans were drafted for the voyage, then a list of supplies was prepared, with enough provisions to last for at least two years. In addition to the forty tons of food, 120 tons of coal, 40 tons of anthracite and large amounts of drinking water were also taken on board. The ship will go through 1800 kilograms of coal each day.
Among the crew members, there was a well-known Romanian scientist, Emil Racoviță (who will be the subject of a separate article). He was entrusted with the photographic laboratory and its equipment for producing images onto special glass plates which were ordered specifically for the expedition.
Thus, “Belgica” entered history as the first ship to penetrate the Antarctic ice and spend more than one year there. Further historical information on the discovery of the Antarctic realms can be found here. Also, it is worth reading about the attempts made by explorers in their quest to conquer this land, and the stories that emerged in relation with some of these places.
From the end of the 19th century and the beginning of the 20th right up to our times, this part of the Globe has been studied by scientists from all fields of science, and numerous research stations have been set up, some permanent and others temporary, which host between 1000 people during winter and 5000 in the summer months.
In the “Land of the eternal ice”, as this continent is sometimes named (though the word “eternal” is called into question nowadays), temperatures can plummet to -89 degrees Celsius (as measured at the Russian station “Vostok” on July 21st 1983) and 98% of its surface is blanketed by a layer of ice with a thickness of at least 1.6 kilometres. Therefore, what kind of lakes are we talking about?
With the help of satellites, radars and infra-red imagery, it was possible to discover under the ice cap a number of lakes and subterranean hydrographic networks. Today, in Russian, American and British laboratories, scientists prepare the necessary equipment for exploring the Antarctic through new projects. The mysterious depths of the ice cap will be investigated, together with the ice rivers that flow among 350 isolated freshwater lakes.
Vostok Lake, discovered in 1970 by airborne radars, is by far the largest sub-glacial lake found so far. Its name comes from the Russian station created in 1956. Russian scientists were the first ones capable of drilling down to a depth of 3.769 metres, in a mission that stared more than ten years ago. In 1993, British specialists from university College London managed to map the lake, by means of data provided by radars. Located almost four kilometres below the frozen Antarctic surface, this lake has a length of 250 kilometres and a width of 50 kilometres. In May 2005, an island was identified in its middle region.
It the water samples that were collected, the Russian researchers hope to find new micro-organisms, unknown to science, and clues about the evolution of life in this part of the world.
These organisms have spent a very long time without coming into contact with the atmosphere, devoid of sunlight, declared Valeri Lukin, the project’s leader, who works at the Russian’s Federation Institute for Arctic and Antarctic Studies. But there are voices saying that the microbes collected so far seem to come from the drilling equipment rather than from the lake itself.
Another sub-glacial lake that has enjoyed the attention of scientists is Lake Whillans. Recently, a team of American researchers managed to reach the lake’s surface, according to the BBC. It is to be found 800 metres below the ice cap, in the western part of the Antarctic, and covers an area of 60 square metres. Scientists claimed that the sensors of the drilling installation detected a change in pressure, signalling that the lake’s surface had been reached. Next, a video camera was sent in to verify the discovery. By using a hot water drill, they dug a hole 30 centimetres wide in the ice above the lake. After that, a number of instruments were lowered into the water in order to collect samples and sensors were used to measure the lake’s properties and characteristics.
Some samples were studied on the spot, inside temporary labs located on the ice around the drilling site, whereas others will be sent to participating universities for a more detailed analysis.
It could be the first proof of life from a sub-glacial lake in the Antarctic, declared journalist Douglas Fox for The Crux, as quoted by NBC News.
Until now, more than 300 large water bodies have been identified underneath the Antarctic. The reasons why this water stays liquid are geothermal heat and pressure.
Scientists want to study the sub-glacial hydrological systems of the Antarctic Continent, because liquid water under the ice layer affects the continent’s movement (for example, ice above Whillans Lake moves almost 300 metres per year), and such knowledge could be very useful when creating forecasts and estimations of global warming.
2011 marked the beginning of a new adventure in the American project, this time at Ellsworth, in Western Antarctica, where another “invisible lake” is to be found, a reservoir 10 kilometres long and 3 kilometres wide, beneath 3.5 kilometres of ice. The drilling will not involve aggressive chemical mixtures, but only warm water, filtered and sterilized by ultra-violet radiation. Then, pressure sensors, a camera and a robot for collecting sediments will be inserted in the tunnel. Everything will be perfectly sterilized in advance, so as not to contaminate the potential underwater lifeforms. Experts believe the lake has been “disconnected” from the outside world for a sufficiently long time that its microbial life has evolved independently.
Everything must be done as cleanly as possible, as sterile as possible. We do not want to contaminate this pristine environment, and if we will not keep our experiment sterile, we will end up analysing what we brought down with us from the surface, and that would, of course, be useless, said Martin Siegert, a scientist working on the project.
Massive, but delicate, that is how chief engineer Andy Tait describes the operation.
The water of Ellsworth Lake is kept liquid by heat seeping from the earth’s depths. The lake was mapped using radars and seismic tests, and on this occasion, it was noted that its bottom is soft, which led researchers to assume that the bottom is covered by a thick layer of sediments.
Lake Vida of Antarctica has characteristics that, at first sight, would make it inhospitable to life: its waters are seven times saltier than the Ocean, its temperature is thirteen degrees Celsius below freezing and its depths are pitch-black. And still, after penetrating twenty metres of ice, scientists were surprised to discover that it was teeming with life, reports descopera.ro.
Its life forms are represented by bacteria, and their discovery fuels hopes that someday, life will be found on planets such as Mars or on natural satellites like Europa, Jupiter’s moon.
What happened at Lake Vida, explained scientists from Illinois University and Desert Research Institute of Reno – USA, could happen with lakes on other celestial bodies, when temperatures are low enough to allow the formation of thick ice caps.
Bacteria from Lake Vida, brought to the surface by drilling at depths of 27 metres, belong to species previously unknown to science. These creatures probably survive by metabolising large amounts of hydrogen and nitrogen oxides that are found in the lake’s salty and oxygen-deprived waters.
Scientists have been puzzled by the large quantities of hydrogen, nitrogen oxides and carbon discovered in Lake Vida, and presume that these substances may have been formed by reactions between salts and chemical compound rich in nitrogen that exist in surrounding rocks. More information can be found here and here.
Over time, oxygen-deprived bacteria have adapted to use these substances for energy production. It is believed that the lake’s unusual conditions played an essential role in the evolution its life-forms’ diversity and characteristics.
Scientists now try to find out more, by cultivating some of these bacteria in laboratory conditions. Thus, they hope to better understand the physical and chemical limits these creatures can withstand.
Antarctica remains a land of many unknowns for science, and the results of these resent investigations could alter our theories about the Earth’s history.
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Article written by Răzvan Spiridon and translated by Mihail Mitoșeriu.
