Surface elevation change on ice caps in the Qaanaaq region, northwestern Greenland

Abstract A large number of glaciers and ice caps (GICs) are distributed along the Greenland coast, physically separated from the ice sheet. The total area of these GICs accounts for 5% of Greenland’s ice cover. Melt water input from the GICs to the ocean substantially contributed to sea-level rise over the last century. Here, we report surface elevation changes of six ice caps near Qaanaaq (77°28′N, 69°13′W) in northwestern Greenland based on photogrammetric analysis of stereo pair satellite images. We processed the images with a digital map plotting instrument to generate digital elevation models (DEMs) in 2006 and 2010 with a grid resolution of 500 m. Generated DEMs were compared to measure surface elevation changes between 2006 and 2010. Over the study area of the six ice caps, covering 1215 km 2 , the mean rate of elevation change was −1.1 ± 0.1 m a −1 . This rate is significantly greater than that previously reported for the 2003–2008 period (−0.6 ± 0.1 m a −1 ) for GICs all of northwestern Greenland. This increased mass loss is consistent with the rise in summer temperatures in this region at a rate of 0.12 °C a −1 for the 1997–2013 period.