Thermal Drilling of the Glacier

The basic knowledge concerning the structure of the deep layers of the ice sheet in the Antarctic and the processes occuring there has been obtained from direct measurements in boreholes and studies of core samples. However, until the present time, the main obstacle to such studies has been the difficulty in drilling adequately deep boreholes in ice. Thermal drilling is one of the techniques for drilling the ice, acquiring ever greater popularity in the Antarctic. The idea of obtaining boreholes in the layer of glaciers by thermal drilling has attracted the attention of researchers for a long time owing to the natural tendency to utilize the surprisingly low melting temperature o ice as a rock, forming the glaciers. The first successful experiments in thermal drilling of glaciers were conducted by Blumke and Hess in the Alps as early as the beginning of this century (Paterson, 1969). The purpose of the present report is to attempt to classify the basic methods involved in the thermal drilling of glaciers, to present certain findings in the operations on the thermal drilling of glaciers in the Antarctic, and also to analyze theoretically the basic processes giverning the thermal drilling conditions during passage through ice and typifying the conditions in the ice layer both ahead of the moving thermal drill as well as the side walls of the borehole.