The Antarctic is losing much more ice than previously thought. An international team of researchers comes to the conclusion that the annual Eisverlust has increased six-fold since the eighties. Is not affected, therefore, only the West Antarctic, but, surprisingly, also the previously considered rather as a stable force East of the continent. Cause movements especially warmer sea, as the Team led by Eric Rignot of the University of California, Irvine, in the “Proceedings” of the US National Academy of Sciences (“PNAS”).
Already, from previous studies it is known that the Antarctic is losing a lot of ice that contributes to sea level rise. Previously, scientists thought, however, that especially the Western part of Antarctica is affected, as well as the narrow Antarctic Peninsula which extends far to the North in the direction of South America.
The Team Rignot calculated now, ice thickness, among other things, data, flow velocity and gravity, a balance sheet for 176 pond at the edge of the Antarctic ice sheet. With the help of these results, the researchers then determined the mass loss of the entire ice sheet from 1979 to 2017. Therefore he lost
in the first decade (1979-1990) every year approximately 40 billion tons (gigatons). In the following decade (1989-2000) were therefore about 50 gigatons, in the decade after that (1999-2009) 166 gigatons. Photo
In the last period (2009-2017) the Team even from a loss in mass of 252 billion tons per year. For comparison: The lake contains almost 50 billion tons of water. The current value exceeds the Numbers that had been presented to a group of researchers last June in the journal “Nature”. This Team went out in the period from 2012 to 2017, from a loss of 219 billion tons per year.
The researchers Rignot calculate in the new study, the Eisverlust let the sea level from 1979 to 2017 to about 14 mm increase. 6.9 mm is attributable to the West Antarctic, 2.5 mm on the Antarctic Peninsula and 4.4 mm in the melt in East Antarctica.
“This is, so to speak, only the tip of the iceberg,” said Rignot. The Antarctic ice sheet is starting to take continue, in the coming centuries, a sea level rise of several meters alone through the Antarctic. The period to which the study relates, was the longest on the ice of the Antarctic.
the immune Stable and against change?
Overall, the focus of the Eisverlust on those areas, ranging from warm, salt and deep water would be achieved. In East Antarctica, in particular in the area of Wilke land is affected accordingly.
“Our observations, the traditional view of the question, according to which the East Antarctic ice sheet is stable against a change immune,” write the researchers. Therefore, you should devote even greater attention. In particular, for the Region, Wilke country, better data would be needed urgently, they emphasize.
“The study confirms that in some regions, glaciers have accelerated. This reinforces the Eisausfluss,” says Martin Horwath of the Technical University of Dresden. The expert for earth system research, who was not involved in the study, considers the investigation for the to date most comprehensive assessment of the mass changes of the Antarctic ice sheet with the help of the researchers methodology. However, he sees in it also the weaknesses. Thus, the authors remained details guilty how close their projections Figures come to Eisbilanz the actual values.