This image might look pretty, but it holds a glum message: it shows that the Antarctic ice sheet is now losing 159 billion tonnes of ice each year. We already knew that Antarctica was melting, but this image — created by a team of scientists from the UK's Centre for Polar Observation and Modelling using data from CryoSat — shows exactly where it's happening.
Cryosat is a satellite that carries a radar altimeter capable of measuring the surface height variation of ice in fine detail — allowing scientists to record changes in ice volume.
The results show that Antarctica's ice sheet is now losing 159 billion tonnes of ice a year — twice as much as when it was last surveyed. In the image, red indicates ice thinning while blue colorings indicates thickening. Deep, dark red — of which there happens to be a lot! — is a Bad Thing. Dr Malcolm McMillan, lead author of the study, explains:
"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 4-8 m per year near to the grounding lines — where the ice streams lift up off the land and begin to float out over the ocean — of the Pine Island, Thwaites and Smith Glaciers."
Those losses alone are enough to raise global sea levels by 0.45mm each year — and it shows no signs of slowing unless we do something drastic. [ESA]