An accurate picture of ice loss in Greenland

German-American GRACE (Gravity Recovery and Climate Experiment) satellites, two satellites that have been orbiting the earth behind each other since mid-2002. Click here for more information.

Researchers from TU Delft joined forces with the Center for Space Research (CSR) in Austin, Texas, USA, to develop a method for creating an accurate picture of Greenland's shrinking ice cap. On the strength of this method, it is now estimated that Greenland is accountable for a half millimetre-rise in the global sea level per year. These findings will be published in the scientific journal Geophysical Research Letters in early October.

The research was based on data from the German-American GRACE (Gravity Recovery and Climate Experiment) satellites, two satellites that have been orbiting the earth behind each other since mid-2002. Deviations in the earth's gravitational field cause fluctuations in the distance between the satellites, which is measured to a precision of a millionth of a metre. As gravity is directly related to mass, these data can be used to plot changes in the earth's water balance, such as the disappearance of the ice caps. Satellite data of this kind are ideal for measuring areas such as Greenland, where the extreme conditions make local measurements very difficult. With this in mind, researchers from TU Delft and the CSR devised a method that would create a more accurate picture of the changes taking place in Greenland than had previously been possible.

Greenland lost an average of 195 cubic kilometres of ice per year between 2003 and 2008, which is enough to cause an annual increase in the global sea level of... Click here for more information.

Sea level rise