Antarctica is now losing about 160 billion tons of ice a year to the ocean – twice as much as when the continent was last surveyed, says scientists.
A team of scientists from the UK Centre for Polar Observation and Modeling, led by researchers at the University of Leeds, have produced the first complete assessment of Antarctic ice sheet elevation change. They used measurements collected by the European Space Agency’s CryoSat-2 satellite mission, which carries an altimeter specially designed for this task.
On average, West Antarctica lost 134 gigatons of ice, East Antarctica three gigatons, and the Antarctic Peninsula 23 gigatonnes in each year between 2010 and 2013 – a total loss of 159 gigatons each year.
The polar ice sheets are a major contributor to global sea level rise and, when combined, the Antarctic losses detected by CryoSat-2 are enough to raise global sea levels by 0.45 millimeters each year alone.
In West Antarctica, ice thinning has been detected in areas that were poorly surveyed by past satellite altimeter missions, said researchers.
These newly-mapped areas contribute additional losses that bring altimeter observations closer to estimates based on other approaches. But the average rate of ice thinning in West Antarctica has also increased, and this sector is now losing almost one third (31 per cent) as much ice each year than it did during the five year period (2005-2010) prior to CryoSat-2′s launch.
“We find that ice losses continue to be most pronounced along the fast-flowing ice streams of the Amundsen Sea sector, with thinning rates of between 4 and 8 meters per year near to the grounding lines of the Pine Island, Thwaites and Smith Glaciers,” said lead author Dr Malcolm McMillan from the University of Leeds.
Via Dr. Stefan Gruenwald