Glaciological investigations on modern ice sheet response in South Greenland
Abstract
The reaction of the large ice sheets to global climate change is still in the focus of scientific debate. Recent investigations have shown pronounced thinning in the southern part of the Greenland Ice Sheet. In order to investigate the cause of the observed thinning in this area and to judge the sensitivity of this part of the ice sheet a combined field work, remote sensing and modelling project was designed. A glaciological transect was established in May 2001 on one of the main outlet glaciers in South Greenland, where the first data series have been collected. This transect aims on monitoring the modern climatic conditions in an area of the ice sheet which is strongest affected by the recently observed thinning. A mass balance/elevation relation has been calculated from the field data, which is used as input to a regional ice dynamic model for investigating the dynamic conditions of this area. Modelled surface velocities are compared to GPS field measurements in order to constrain model parameters. Results show that the sensitivity of the ice sheet to climatic changes varies considerably along the southern margin. The history of the glacier variations in the same area during the last 40 years has been reconstructed on the basis of aerial photographs and satellite images. Comparing the development of the retreat in this area over the last decades with the maximum extent of the ice sheet from the 1890s indicates a strong increase in the recession of the margin. The estimated thinning from these observations is in good agreement with the recent laser altimeter measurements. The observed surface lowering is also responsible for the fast disintegration of several glacier tongues of tide water glaciers in the area.
- Publication:
-
EGS - AGU - EUG Joint Assembly
- Pub Date:
- April 2003
- Bibcode:
- 2003EAEJA.....9608M