f Drilling and borehole geophysics in alpine permafrost

Drilling in mountain permafrost is quite different from drilling at other places: the inhomogeneous formation consisting of 'hard' rocks and 'soft' ice, and the temperature close to the melting point of ice are the most difficult of several factors. A number of parameters can be measured along the borehole facilitating the understanding of surface geophysical investigations and of ongoing processes in the permafrost Here, we present all overview of experiences from several permafrost drill sites and list some possibilities for drilling and borehole geophysical rrieasurements in mountain permafrost. This includes the saving and analysis of cores, borehole television camera, borehole logging and long-term monitoring installations (temperature, deformation). The aim of the borehole logging (Gamma-ray, Gamma- Gamma, Neutron-Neutron, Resistivity, Sonic) is to determine the thickness of the perennial frozen debris layer above the bedrock and to investigate P-wave velocity, resistivity and ice content of the whole permafrost body. In addition, main results from several permafrost boreholes in the Swiss Alps and Svalbard (Spitsbergen) are presented.