Radio-echo soundings are done to map the bed topography under Vestfonna ice cap.

At last we have started to do radio-echo soundings to map the bed topography under Vestfonna ice cap. We make the soundings to complete air-borne soundings done 1986/1987 by Scott, Polar Research Institute, UK. The older soundings were not able to penetrate to the bed in the central parts of the ice cap and we are now filling in the blank areas. Accurate bed topography of the ice cap is important for different kinds of modeling efforts later on.

We concentrated on the south-western part of the ice cap and made a zig-zag pattern with radio-echo sounding profiles along the ridges of the ice cap. In total, we succeeded to acquire about 50 km of profiles before the weather turned too bad for continuing the work. Some interesting features we could see in the radar data is that it seems to be patches of temperate firn and ice in low areas between summits on the ridges. Potentially, it can be the result of melt water that percolates and accumulates in the lower areas during summer and make the firn (and eventually the ice) in these areas temperate. This can give new insight of firn hydrology and the temperate regime of the ice cap.

Richard Pettersson, Institutionen för geovetenskaper, Uppsala universitet