Warm ocean currents are melting Antarctic ice

Recent ice loss from Antarctica was mainly caused by warm ocean currents, according to a team of scientists led by British Antarctic Survey. In an article for the journal NATURE this week, they explain how they used new techniques to differentiate for the first time between the two known causes of melting ice shelves – warm ocean currents attacking from below and warm air melting from above. One worrying thing is that this means “we can lose an awful lot of ice to the sea without ever having summers warm enough to make the snow on top of the glaciers melt – the oceans can do all the work from below” says Dr. Hamish Pritchard from BAS, lead author of the report.

The warm water melting the ice sheets is causing inland glaciers to speed up and discharge masses of ice into the sea. The reason the water is warming, is probably because of changes in wind patterns, caused in turn by changes in climate. This would mean “Antarctica’s glaciers are responding rapidly to a changing climate” says Pritchard.

Most of the ice shelves being melted by warm ocean currents are in West Antarctica. On the eastern Antarctic Peninsula the shelf thinning  found by the study can be explained by warmer summer winds directly melting the snow on the ice shelves.

The results will help improve projections of future sea-level rise.

More here on the website of the British Antarctic Survey