Bore-Hole Video and Photographic Cameras

Abstract

35 mm still and television techniques are shown to be of great value in following changes at the bedrock/ice interface and along borehole walls during closure over one or more years in polar or sub-polar ice caps. We have found no evidence of basal slip over a one year period in a 137 m hole at the top of the flow line on an ice cap in northern Ellesmere Island, However, the bore hole has deformed to an elliptical cross-section near the bed and some pronounced extrusion-like layers have developed within 3 m of the bed in dirty ice in the year since drilling.