Scientists from the European Space Agency recently discovered that the loss of ice in Antarctica is so significant that it’s affecting the Earth’s gravity. The researchers paired data from the ESA’s GOCE satellite with data from the GRACE system of satellites and found that the Earth’s gravity dipped in the area because the ice lost so much mass.
The GOCE project has provided the most accurate gravity model ever produced. Teams from the German Geodetic Research Institute, Delft University of Technology, NASA’s Jet Propulsion Lab, and the Technical University of Munich just completed analysis of the data collected from the GOCE satellite when it passed over Antarctica between November 2009 and June 2012. The gravity measurement mission was not designed to detect changes over time, but when the high-resolution data was paired with the cruder data from the NASA-German GRACE satellite system, which is designed to detect temporal changes, the results were surprising. A time-lapse video illustrating the data can be viewed here.
The team found that the decrease in the mass of ice during this period was mirrored in GOCE’s measurements. The accuracy of the GOCE data allowed the team to look at smaller catchment basins in the area. In addition to demonstrating that there was a dip in gravity to correspond with the loss of ice mass, the team believe the GOCE data could help give an even clearer understanding of ice sheet and sea level change. The ESA’s CryoSat satellite recently showed that since 2009 the rate at which ice has been lost from the West Antarctic Ice Sheet has increased by a factor of three. It also showed that since 2011, Antarctica as a whole has been shrinking in volume by 125 cubic kilometers a year.
With a sad irony, the GOCE satellite succumbed to the force of gravity in 2013 after doubling its expected mission life. But its data will continue to be useful. Johannes Bouman from the German Geodetic Research Institute says, “We are now working in an interdisciplinary team to extend the analysis of GOCE’s data to all of Antarctica. This will help us gain further comparison with results from CryoSat for an even more reliable picture of actual changes in ice mass.”