Lake Vostok- a lost world

Photo courtesy of US Embassy New Zealand 

You may be delighted to hear that there is an area on Earth that remains un-spoilt by humans, which in this day and age, is incredibly rare. Many ecosystems have in some way, been imprinted on by humans and so news of a hidden, ‘untouched’ lake lying beneath the Antarctica ice sheet is extremely welcome. Lake Vostok lies beneath 4km of ice and has been secluded from the rest of the planet for over 20 million years.

This concealed lake is one of the largest lakes in the world with regards to sheer volume. It is 670m deep, contains more than 4,000 cubic km of water and covers an area approximately half the size of Wales. This lake was formed a staggering 30 million years ago when the Antarctic experienced an increase in temperature, causing ice to melt. The temperature then re-cooled forming glaciers around Vostok. Over time these glaciers began to slide down across the lake creating a lid over the water, concealing it from the rest of the world. It has now been 20-15 million years since the lake has seen sunlight, and all life that once thrived would have perished.

Scientists are obviously very keen to discover what life currently exists in this lake. For 20 years a team of Russian scientists have been drilling into the thick layer of ice that lies above the buried lake, hoping to soon break through into the lake below. Drilling began in February 1990 and within a year reached an impressive depth of 2,500m; however, various delays thereafter meant that the next 1000m took a disappointing 20 years to drill. To date, there is only 30m left to drill until the surface of the lake is reached. When the drill eventually reaches the surface of Vostok Lake, the drill will seal off the borehole to avoid contaminating the once hidden water mass.

Once the ice has fully been drilled through, the pressurized lake water will be pushed into the channel and will eventually refreeze. When refrozen, samples will be removed for analyzing. Samples have already been taken from the frozen lake water just above the lake and have shown evidence of bacterial life.

Scientists are only expecting to find bacteria in the lake water. These bacteria would have evolved to withstand extreme temperatures and survive without sunlight. Even though the discovery of bacteria doesn’t sound as exciting as discovering a new animal, it still shows that life can survive in such isolated and extreme conditions.

The most cause for concern during this discovery is the risk of contamination to the hidden lake. This project was initially aimed to extract ice cores, not to discover the lake. To prevent the channel from refreezing, oil based kerosene was used and if any was to enter the lake, it would have caused major effects on the lakes ecosystem. Therefore; NASA are currently evolving a more sterile approach to investigating the isolated lake.

To date, the lake water has yet been obtained and sampled, but when it eventually is, it will be very interesting to see what living organisms the untouched water holds.

By Laura Ireson