The melting ice of the Antarctic was feared, it looks even worse than expected. In fact, this cast iron annual is faster than ever, about six times more than it did 40 years ago, resulting in an increase of more important the level of the oceans, were accused Monday of the scientists. The lessening of the ice of the white continent is responsible for a rise of 1.4 cm at the level of the oceans of the world between 1979 and 2017, according to a report of the records of the us national Academy of sciences (PNAS).
And the melt rate anticipated should result in increased disturbance of this level in the coming years, noted Eric Rignot, president of the chair of the scientific system of the Earth at the university of California (Irvine). “With the ice sheet in the antarctic continues to melt, we expect an increase in sea level of several meters due to the Antarctic in the next few centuries “, he added.
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According to previous studies, a rise of 1.8 m by 2100 – the worst scientific forecasts – would result in the flooding of many coastal cities, home to millions of people in the world.
For the new study, whose findings are published Monday, the researchers conducted the longest evaluation of the mass of ice in 18 regions of the Antarctic. They used data provided by aerial photographs in high resolution taken by aircraft of Nasa, as well as radar images from satellites from multiple space agencies.
They have found that between 1979 and 1990 the Antarctic had lost an average of 40 billion tonnes of ice mass per year. From 2009 and until 2017, this increased to 252 billion tons each year.
even More disturbing, scientists have identified areas in the East, once considered relatively ” immune to change “, in contrast to those of the West, who are now losing a lot of ice. “The region of the land of Wilkes, eastern Antarctica, has, overall, contributed significantly to the loss of mass even up to the 1980s,” said Eric Rignot.
Elevation of 57 meters above sea level
“This region is likely to be much more sensitive to climate than was traditionally assumed, and it is important to know because it has more ice than the Antarctic from the West and the antarctic peninsula together,” he continued.
Antarctica contains enough ice to cause, if the latter were to completely melt away, an elevation of 57 meters above sea level. The vast majority of the ice is concentrated in Antarctica, with what to do to ride the seas of 52 metres in the case of cast iron, against 5 metres to the west. The ice cap of Antarctica, the largest in the world, contains approximately half of the freshwater reserves of the planet.
Melting ice : “increased attention”
A study of reference published in June 2018 in the journal Nature reported that the melting of Antarctic ice had tripled since 1992, without, however, show a significant impact in the East.
another major study analyzed, however, three months later, in the same review, layers of sediment of the ocean floor, deposited during the last melting of the basin subglacial Wilkes, in the Antarctic, there are 125 000 years. This study has shown that this huge basin would begin to melt again in the event of a temperature rise of 2 °C, the upper limit set by the Paris agreement to mitigate climate change.
The latest research should encourage them to bring “attention” to the melting of the ice in the east Antarctic, has highlighted the report in PNAS. According to the scientists, the warming of the ocean water will further accelerate the melting of the ice and the sea level will continue to rise for centuries, regardless of efforts being made to combat climate change. Their temperature, have been demonstrated in recent studies, warms more quickly than thought scientists and have reached record highs in recent years.