Close encounters of the 3rd kind under Antarctica’s old blue ice
Near mountain ranges, multi-millennia-old ice resurgences are home to active ecosystems never before recorded.
The high plateaus of Antarctica are dry and cold. Hostile. If anyone looks for signs of life, they’re likely to come across ghosts as Scott and his companions trudge through the blizzard. Sheltered by mountain ranges, snow is rare and the wind sweeps across a surface of shiny ice. It’s the toughest, the blue ice. Millions of years old, it enables large aircraft to land and take off. Near Norway’s Troll station, a runway is levelled out on a promontory, where this ice flows rapidly. “Every year, they re-surface it,” says Aga Nowak, an ecologist at the Svalbard University Center. “And when we talked to them, they told us ‘sometimes we have problems, the ice breaks and there’s water underneath.” Liquid water! Published in the journal Communications Earth & Environment on June 24, a British and Norwegian research team revealed that life forms are developing in the high-altitude blue ice of Antarctica. “In an active hydrosystem”, she told Polar Journal AG by telephone. Blue ice on the cap covers an area the size of Great Britain.
But how is this possible? It’s liquid water, of course, but temperatures never rise above zero degrees. It requires energy. In summer, the sun brings it to the South Pole. The rays pass through the frozen water. If conditions are right water bodies can develop even at 10 meters depth. Dark particles of rock, caught in this solid mass, also store the heat. These debris are said to come from glacier beds and mountain ranges. Under the weight of the ice cap, the blue ice rises in folds. It took millennia for it to reappear, in places encrusted with particles. Around this debris, “cryoconite holes” form. They range in size from 10 centimetres to 8 metres, as in the case of those discovered around the Troll station. “There’s water and gas. A little greenhouse effect is being created,” explains the researcher. ” There’s cyanobacteria capable of photosynthesis, even in low light. We also recorded heterotrophic bacteria that produce CO2. Some of them were never recorded in those conditions before.” So, if the heights of Antarctica are a desert, here are the oases.
These microorganisms are adapted to conditions that could be those of Jupiter’s icy moon. “It’s a similar environment, so I think it’s possible to find similar forms of life, on Europa or other moons,” she believes. There were no visible signs of their presence in Antarctica from space. Gravitating close to Europa, the Juno probe is unlikely to be able to do this either.
This life produces and transforms matter (carbon, nitrates, phosphates, etc.) into nutrients. The quantities are far from negligible. Imagine an eight-ton bag of fertilizer per square kilometer. One question is on the researcher’s mind: Do these elements reach the Southern Ocean, contributing to its fertilization ? “These ‘cryoconite holes’ are close to known drainage areas,” she notes. “I think the water can go down into the ice, be distributed within the ice sheet and below it, and then be evacuated to the ocean. This contribution of high elevation blue ice areas have never been considered before, as we always looked at inland Antarctic ice as barren and dry. We now show this is far from true.”
Camille Lin, Polar Journal AG
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