1. Dept. of Physical Geography, Institute of Geosciences, University of Oslo, Box 1042 Blindern, NO-0316 Oslo, Norway, and Dept. of Geology, University Centre in Svalbard, NO-9170 Longyearbyen, Norway,
2. Instanes Consulting Engineers, Storetveitveien 96, NO-5072 Bergen, Norway;
3. Dept. of Physical Geography, Institute of Geosciences, University of Oslo, Box 1042 Blindern, NO-0316 Oslo, Norway.