Glaciers are responding rapidly to climate change and are likely to be the second largest contributor to sea level rise over the 21st century. However there are large uncertainties in the mass balance estimation in particular for calving glaciers, the main contributors to ice loss in certain climatic sensitive areas. In order to understand and develop realistic scenarios for glacier depletion, spatial detailed information on the surface elevation change is needed. In addition, an estimation of the individual components of the glacier mass balance contributes to a better comprehension of thinning or thickening.
In the present work we are using multitemporal bistatic TanDEM-X datasets acquired over the South Patagonia Icefield to provide time series of ice surface elevation. We are focusing on several of the major outlet glaciers to complement the information on ice thickness change over entire basins with the ice loss due to calving at the terminus in the same period of 1 to 4 years. The calving flux can be estimated from frontal retreat and terminus velocity derived from TerraSAR-X repeat pass acquisitions as well as bathymetry data at the front. The ice elevation changes from TanDEM-X integrated over the glacier surface can be converted into mass change in the time interval between the DEM data acquisitions. The comparison of the total mass change and mass loss due to calving gives insights into how realistic the surface mass balance values resulted from modelling are.