LONDON, May 19 (Xinhua) -- The Antarctic ice sheet is losing 159 billion tonnes of ice each year, twice as much as when it was last surveyed, according to a three-year observation by Europe's satellite.
The findings by a team of scientists led by Leeds University researchers were published Monday on the American scientific journal Geophysical Research Letters.
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 gigatonnes of ice, East Antarctica three gigatonnes, and the Antarctic Peninsula 23 gigatonnes in each year between 2010 and 2013 -- a total loss of 159 gigatonnes each year, and twice as much compared with the data from last survey conducted from 2005 to 2010.
Researchers wrote in the report that, 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 mm each year alone.
Launched in 2010, CryoSat-2 carries a radar altimeter that can "see through" clouds and in the dark, providing continuous measurements over areas like Antarctica that are prone to bad weather and long periods of darkness.
The radar can measure the surface height variation of ice in fine detail, allowing scientists to record changes in its volume with unprecedented accuracy.
Professor Andrew Shepherd of the Leeds University, who led the study, said: "Thanks to its novel instrument design and to its near-polar orbit, CryoSat allows us to survey coastal and high-latitude regions of Antarctica that were beyond the capability of past altimeter missions."
The increased thinning that was detected in West Antarctica is a worrying development, which adds concrete evidence that dramatic changes are underway in this area, he said.
The challenge is to use this evidence to test and improve the predictive skill of climate models, according to the researcher.