Volume 38 (1976) Issue Special Pages 37-38
Thermal drilling was carried out in August of 1974 on the Khumbu glacier. The drilling site was set at 5360 m above sea-level in the upper part of the ablation area of the glacier. The drilling was stopped due to the freezing of the drilled hole at a depth of 20.3 m. The analysis of the relationship between the depth and the time of drilling indicated that there were 7 layers down to the maximum depth reached and there was a possibility that the deepest layer was at the melting point. A simple calculation of the freezing rate of the drilled hole showed that the ice temperature at a depth of 2 m was below -2°C at the drilling time. The measurement of the resistance of a thermistor put into the hole showed that the ice temperature at a depth of 2.7 m was -5.3°C at the end of November. Therefore, it was concluded that the ice temperature above the deepest layer (its depth was 16 m) was below the melting point, but it was at the melting point below the layer. This conclusion was supported by the analysis of the flow velocity of the glacier.