The Greenland ice sheet has been losing mass at a significant rate during the past several years, contributing to global sea level rise.
Recent studies show dramatic ice loss along the southeastern coast.
Khan et al. combine Global Positioning System (GPS) measurements with measurements from the Gravity Recovery and Climate Experiment (GRACE) satellite to determine that the ice mass loss is accelerating and also spreading into northwestern Greenland.
The GRACE satellite, launched in 2002, measures changes in Earth's gravity field and can detect the motions of the Earth's crust that occur when ice melts. GRACE detects this uplift over large regions, while long-term observations from permanent GPS stations can be used to monitor uplift on smaller scales.
Acceleration of ice mass loss on the northwestern coast likely started in late 2005, the researchers find. In addition to documenting the spread of ice loss, the results also confirm the consistency between GRACE and GPS measurements, showing that the combination of the two types of measurements provides a useful new approach for scientists studying ongoing ice loss.
Title: Spread of ice mass loss into northwest Greenland observed by GRACE and GPS, Shfaqat Abbas Khan: DTU Space, Department of Geodesy, National Space Institute, Copenhagen, Denmark;
John Wahr: Department of Physics and Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder, Boulder, Colorado, USA; Michael Bevis, Eric Kendrick: School of Earth Sciences, Ohio State University, Columbus, Ohio, USA; Isabella Velicogna: Department of Earth System Science, University of California, Irvine, California, USA, and Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA. Geophysical Research Letters DOI:10.1029/2010GL042460, 2010