New understanding of Antarctica’s weight-loss

New data which more accurately measures the rate of ice-melt could help us better understand how Antarctica is changing in the light of global warming.

The rate of global sea level change is reasonably well-established but understanding the different sources of this rise is more challenging. Using re-calibrated scales that are able to 'weigh' ice sheets from space to a greater degree of accuracy than ever before, the international team led by Newcastle University has discovered that Antarctica overall is contributing much less to the substantial sea-level rise than originally thought.

Instead, the large amount of water flowing away from West Antarctica through ice-melt has been partly cancelled out by the volume of water falling onto the continent in the form of snow, suggesting some past studies have overestimated Antarctica's contribution to fast-rising sea levels.

Using Gravity Recovery and Climate Experiment (GRACE) satellite data, the team calculated ice sheet mass loss by more accurately mapping and removing the mass changes caused by the flow of rock beneath Earth's surface.

Publishing their findings today in the academic journal Nature, project lead professor Matt King said the data meant we were at last close to understanding how Antarctica is changing.

''We have tried to weigh the ice in the past but GRACE only measures the combined effect of the ice changes and the land mass changes occurring beneath the Earth's surface,'' explains Professor King, Professor of Polar Geodesy at Newcastle University. ''The step forward we have made is to provide a better calculation of the land mass changes so we can correct the satellite measurements to more accurately calculate the changes in ice mass alone.