Discovery of a long river hidden under Antarctica

Under the ice of Antarctica, things are happening that you don’t suspect. Some time ago, researchers had found lakes there. Now, today, they reveal to us that there flows a river several hundred kilometers long. And that this could have unfortunate consequences on the melting of the ice in the context of global warming.

A few decades ago, researchers discovered that lakes are hiding under the ice of Antarctica. And gradually they realized that these lakes are interconnected. Connected by rivers, sometimes of size. Like this river some 460 kilometers long that an international team has just unearthed. Four hundred and sixty kilometers is a little less than the Garonne and its 529 kilometres. Much more than the Thames (United Kingdom) and its 346 kilometres.

What is important, above all, is that the researchers show that this river collects water at the base of the ice capice cap Antarctica, in an area the size of Germany and France combined. What to indicate that this base of ice cap presents a debitdebit of water more active than scientists previously thought. And that could make it more susceptible to climate change. So, when you know that everything is played in a region that retains enough ice to raise the sea level by more than four meters…

Recall that water can form under the ice caps in two ways. In L’ArcticArctic, for example, the surface melts strongly in summer. Large quantities of water then flow through crevices to reach the bottom. In Antarctica, the summers remain too cold for that. This is why the researchers thought that little water was hiding under the ice. Even though the meltingmelting from the base – caused by heatheat natural of the EarthEarth and the frictionfriction when the ice moves – could form a little.

The missing link in ice melt patterns

But the radar readings taken by this team tell a different story. That of a much larger basal cast iron than scientists had imagined. However, it is only by understanding why the ice is melting that the models can correctly predict the melting to come under the effect of the global warmingglobal warming. “This discovery could be the missing linkmissing link in our models »comments Christine Dow, researcher at the University of Waterloo (Canada), in a press release from theImperial College London (UK).

Discovery of a world hidden under Antarctica

“We could greatly underestimate how quickly Antarctica will melt by not taking into account the influence of these river systems. » For the newly discovered river emerges into the sea under a ice platformice platform floating. Fresh water from the river lifts warmer water down from the ice shelf, melting it from below. Given the length of this river, which reaches hundreds of kilometers inland, the process could play out much more widely than researchers thought.

Scientists also foresee that with global warming and the occurrence of warmer summers in the future, the surface melting could become sufficient to cause water to run off under the ice cap. With significant effects on the river systems lurking there. And an acceleration of the melting of the ice. Not to mention the potential loops of feedbackfeedback – more water causing more friction and more basal melting – which could further amplify the phenomenon. To find out for sure, the researchers will go in search of additional data on even larger regions of Antarctica.

Unknown rivers discovered under Antarctic glaciers

In the 1960s, satellite and aircraft radar systems had revealed the presence of many lakes under the Antarctic glaciers, several hundred meters deep. Scientists previously thought that these biological laboratories were isolated and possibly harboring original life forms, subsisting in extreme conditions.

In a letter to the journal Nature, a team of British researchers calls this fact into question, and announces that they have uncovered a network of rivers linking the different bodies of water. According to them, some sub-glacial links are as wide as the Thames!

Article by Christophe Olry published on 04/20/2006

Subglacial lakes that intrigue and excite

At first, we thought the presence of water liquidliquid impossible under the glaciers of Antarctica: it was too cold there. By the 1960s, radar images had proven otherwise, showing that at least 150 lakes were looming in the depths. The largest of them, with 250 kilometers long and 40 kilometers wide: Lake Vostok; it is readily attributed an age of between 15 and 20 million years.

Since the discovery of these sub-glacial lakes, many scientists have nurtured the hope of drilling into the ice, taking water samples, and finding life forms there. Indeed, if these expanses were isolated – as we thought until then – and had evolved independently of each other, sheltered from the atmosphere, who knows what we could have found there? Life forms subsisting in extreme conditions, conditions similar to those prevailing in the frozen ocean of Europa?

Wide rivers like the Thames…

The most recent research was conducted by Nerc scientists (Natural Environment Research Council), who scanned Antarctica using the satellite ERS-2ERS-2 of the’ESAESA. The analyzes revealed variations in the height of the ice, compared to previous maps, which could only correspond to water movementsand therefore to a connection system : “ Finding out that an entire 30 kilometer by 10 kilometer section had moved vertically was a big surprise. The only possible explanation was water circulation. explains Professor Wingham.

British researchers assume that, on a regular basis, massesmasses of water move from one lake to another, by borrowing rivers which can reach the size of the Thames. Normally, these movementsmovements are moderate but, when a lake is under pressurepressureit can jump like a cork and cause sub-glacial floods that travel for miles.

So the various lakes that run beneath Antarctica’s glaciers aren’t as isolated as previously thought, and taking samples could see the contaminationcontamination of the entire network. Finally, it is possible that, in the past, some of these lakes flowed into the ocean…


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