Lake Vostok: What we know about Antarctica's mystifying subglacial lake

What is the legend of Lake Vostok?

Lake Vostok is located in east Antarctica, about 2.5 miles (4 kilometers) below the ground, covered in a massive sheet of ice. The presence of a buried lake was first suggested in the 1960s, but the discovery of the lake wasn't confirmed until 1993. An article following the discovery was published in the scientific journal Nature in 1996, which integrated data collected over two decades. This included data from radar surveys in the 1970s showing liquid water underneath the ice as well as other imaging and radar observations that led to the confirmation of the lake’s existence.

The size of the lake can be compared to that of Lake Ontario, with measurements reaching an area of around 5,400 m^2 (13,986 km^2). The lake and the Russian research station located on the surface near the lake were both named after the ship Vostok, which means “east” in Russian. This ship sailed on the first Russian Antarctic expedition in 1819-1821, which discovered Antarctica.

What is hidden below Lake Vostok?

Being a subglacial lake, it has always been a wonder knowing that a large body of liquid water exists beneath that many layers of ice. Some might even find it impossible, but the existence of Lake Vostok and all other discovered subglacial lakes tell us otherwise.

The existence of liquid water beneath layers of mile-thick ice sheets can be thought of as uncommon since scientists are still divided on how subglacial lakes are formed.

It is without a doubt that Antarctica has some of the most extreme weather conditions in the world. Surface air temperatures can reach below -76°F (-60°C). In fact, the coldest temperature recorded to date was measured at the Vostok Station on July 21, 1983, reaching -128.6°F (-89.2°C). Despite year-round temperatures well below the freezing point, the existence of liquid water in glacial lakes is thought to occur thanks to several reasons.

A research review article explains how liquid water can exist in such conditions: Sufficient geothermal heat is generated to raise the temperature of the ice to around 27°F. This is still below the melting point of ice, but pressure from the thick ice sheet reduces the melting point and also provides insulation from colder surface temperatures. The result is a liquid lake.

Does life exist in Lake Vostok?

The presence of liquid water on other planets has been thought to suggest the possibility of life outside of Earth. Can the same be said in subglacial lakes?

It has been estimated by scientists that Lake Vostok may have existed for up to 15 million years or more already. The conditions of the lake are also unique because of its location deep beneath the ice, which is devoid of sunlight and doesn’t have direct exposure to the Earth’s atmosphere. That being said, researchers are intrigued by what discoveries, microorganisms perhaps, could be found in the waters of the lake.

The next challenge after confirming the existence of Lake Vostok was how to actually access its waters. In the 1990s, an international research team found microbes in frozen lake water collected from accretion ice (this is water from the lake’s surface that freezes onto the ice sheet above).

What did Russians find in Lake Vostok?

The Russians were the first to sample the water from the largest known subglacial lake in Antarctica. The first samples from Lake Vostok were taken in February 2012, and researchers took more samples in January 2015.

Both sets of samples were taken by using drilling technology to bore holes in the ice sheet just to the lake’s surface. The pressurized lake water then rose into the borehole and froze, to be retrieved later on. Additionally, frozen water samples stuck in the drill bit were also collected together with the ice cores, and both were subjected to biological and microbiological studies.

Research findings published in 2013 identified thousands of using DNA and RNA sequences. These included sequences indicating the presence of a diverse set of organisms, including some similar to those commonly found in the digestive systems of fish, crustaceans, and annelid worms. Around 94% of the organisms were bacteria, and 6% were eukaryotic organisms, mostly fungi. However, accessing the lake’s water is still quite a challenge as the method used to take these two lake extractions may not be the best option in terms of obtaining clean and uncontaminated samples.

Has anything else been found in Lake Vostok?

All this research and entry projects to Lake Vostok aimed to find evidence or any trace that could be indicative of life in the lake’s waters. Microorganisms are the best hope most researchers have in mind in terms of finding life in the lake, considering the conditions that might be present.

A study published in 2020 shows that a community of microorganisms was found in the samples of accretion and basal ice flowing into the lake. Like previous studies, both bacterial and eukaryotic organisms were identified. DNA and RNA sequencing data from the basal ice shows at least 407 species of bacteria and at least 103 species of eukaryotes, including species that can carry out steps in nitrogen cycling. Meanwhile, data from the accretion ice show the existence of more unique sequences from eukaryotic species.

This study also considered the possibility of contamination in their collection methods, as previously suggested in the earlier conducted studies. The results of this study indicate the existence of two complex ecosystems between the accretion ice and the basal ice, with the former being suggested to have a more complex ecosystem thanks to the unique eukaryotic sequences.

Why is Lake Vostok important?

Lake Vostok is well known for being the largest subglacial lake discovered. Aside from this, what makes it intriguing is the possibility of obtaining evidence of life existing within its waters. This is despite the fact that it is under extreme conditions, from the temperature of its water to the complex environment it has beneath the surface.

Life found so far in the samples taken from the lake range includes not only prokaryotes and single-celled eukaryotes but also microorganisms known to be associated with multicellular eukaryotes. Many questions remain, however, including the sources of the nutrients, nucleic acids, organic carbon, and the organisms themselves.

Since the initial and succeeding lake entry projects, all that have been found are sequences of a community of microorganisms identified in the obtained samples.

The case of the 'missing' scientists

What fun would discoveries be without a little bit of intrigue?

A news article from 2016 claimed that scientists, who were out of communication for five days while exploring the location of Lake Vostok, were actually battling a giant, deadly sea creature. As intriguing as it may sound, the report has been shown to be nothing but a science-fiction story made up by the news satire fiction writer C. Michael Forsyth.

If anything were actually to arouse one’s curiosity about Lake Vostok, it would be the possible discoveries that are in store deep below its surface. Who knows what knowledge these discoveries might bring regarding the past or maybe the present? We'll be waiting for scientists to unlock more of Lake Vostok's mysteries.