Satellite lasers show rapid thinning of Greenland and Antarctic ice sheets

Washington, September 24 (ANI): Using satellite lasers, scientists have made the most comprehensive picture of the rapidly thinning glaciers along the coastline of both the Antarctic and Greenland ice sheets.

Researchers from British Antarctic Survey and the University of Bristol describe how analysis of millions of NASA satellite measurements from both of these vast ice sheets shows that the most profound ice loss is a result of glaciers speeding up where they flow into the sea.

According to the researchers, this 'dynamic thinning' of glaciers now reaches all latitudes in Greenland, has intensified on key Antarctic coastlines, is penetrating far into the ice sheets' interior and is spreading as ice shelves thin by ocean-driven melt.

Ice shelf collapse has triggered particularly strong thinning that has endured for decades.

"We were surprised to see such a strong pattern of thinning glaciers across such large areas of coastline - it's widespread and in some cases thinning extends hundreds of kilometres inland. We think that warm ocean currents reaching the coast and melting the glacier front is the most likely cause of faster glacier flow," said lead author Dr Hamish Pritchard from British Antarctic Survey (BAS).

"This kind of ice loss is so poorly understood that it remains the most unpredictable part of future sea level rise," he added.

The scientists compared the rates of change in elevation of both fast-flowing and slow-flowing ice.

In Greenland, for example, they studied 111 fast-moving glaciers and found 81 thinning at rates twice that of slow-flowing ice at the same altitude.

They found that ice loss from many glaciers in both Antarctica and Greenland is greater than the rate of snowfall further inland.

In Antarctica, some of the fastest thinning glaciers are in West Antarctica (Amundsen Sea Embayment) where Pine Island Glacier and neighbouring Smith and Thwaites Glacier are thinning by up to 9 metres per year.

The findings are an important step forward in the quest to make more accurate predictions for future sea level rise. (ANI)