Antarctica: new index on the rise in the sea level
Tuesday, 20 march, 2018 06:19
Tuesday, 20 march, 2018 06:22
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SYDNEY | A glacier in Antarctica a country as large as France, by melting under the effect of global warming, a fleet with more on the ocean than what was thought previously, scientists, aggravating the risks of sea-level rise, said Tuesday the researchers.
The glacier Totten in east Antarctica, is one of the largest glaciers of the white continent. Like other ice caps, it is monitored closely, because it would release huge quantities of water, threatening the hundreds of millions of people living in coastal areas.
A part of the glacier rests on bedrock and the other is spreading at the surface of the water, where it floats. This last part, the ice barrier, is more extensive that what he felt until then the specialists.
In the framework of the Program the Antarctic australian, researchers led by glaciologist Ben Galton-Fenzi, including scientists from the australian Division of the Antarctic and Central Washington University, spent the summer studying the Totten.
In a communiqué issued at the end of the mission, professor Paul Winberry, Central Washington University, explains that they have caused artificially seismic waves to study its structure.
“In some places where it was thought that the ice sheet rested on the earth, we saw the ocean below, which indicates that the glacier is actually in the process of floating “, he said.
The sky, the edges of the glacier do not appear, because the antarctic continent is covered with thick snow and ice of several kilometres.
Recent studies have already shown that the glacier was eroded from below via channels, providing water warm sea.
Over erosion, the proportion of the glacier floating on the water increases, thus accelerating the speed of the decay.
The discovery of the researchers could explain periods to recent accelerated melting, added Mr. Winberry. “It may also mean that the Totten will be more sensitive to future climatic changes “.
According to Nasa, between 2002 and 2016, the Antarctic has lost 125 gigatons of ice per year.
According to Mr Galton-Fenzi, the Totten contains enough ice to raise these levels up to three meters if all were to melt. “Since the 1990s, the overall level of the sea has risen twenty centimeters and by the end of the century, it is expected to increase by up to one meter. But all this is very uncertain, that is why it is important to study glaciers like Totten “, he said.
The Antarctic, concentrating 62 % of the freshwater reserves of the planet, its thawing should contribute to desalinate the seas of the globe, a mechanism is fatal to many marine species.