Publié le 20 mai 2019
By combining 25 years of ESA satellite data, scientists have discovered that warming ocean waters have caused the ice to thin so rapidly that 24% of the glacier ice in West Antarctica is now affected.
A paper published in Geophysical Research Letters describes how the UK Centre for Polar Observation and Modelling (CPOM) used over 800 million measurements of Antarctic ice sheet height recorded by radar altimeter instruments on ESA’s ERS‑1, ERS‑2, Envisat and CryoSat satellite missions between 1992 and 2017.
Cryosat. Image courtesy by ESA
The study also used simulations of snowfall over the same period produced by the RACMO regional climate model. Together, these measurements allow changes in ice-sheet height to be separated into those caused by meteorological events, which affect snow, and those caused by longer-term changes in climate, which affect ice.
The ice sheet has thinned by up to 122 metres in places, with the most rapid changes occurring in West Antarctica where ocean melting has triggered glacier imbalance. CPOM Director, Andy Shepherd, explained, “Parts of Antarctica have thinned by extraordinary amounts. So we set out to show how much was down to changes in climate and how much was instead due to weather.”