A thermal ice drill for profiling thick multiyear ice

An open-system hot water drill for arctic winter operation was developed to rapidly penetrate thickice features for the purpose of measuring ice thickness and for placing instrumentation into and beneath the ice. The thermal drill is composed of five modules, which can be quickly joined or disassembled. Because of its relatively low operating weight of 285 kg and its compact size, the drill can be transported to offshore locations by helicopter and across ice floes by field personnel without motorized support.

In several field programmes, penetration rates as high as 5.5 m/min. were achieved in thick ice and over 24 km of cumulative ice thickness were drilled to date. In one such programme, the performance of the thermal drill was evaluated on a large, thick multiyear ridge drifting in the nearshore Alaskan Beaufort Sea. Ice thickness data were collected along the sail crest and two profile lines perpendicular to the ridge. A total of 61 ice thickness measurements totalling 1300 m were collected in six hours of drilling. Of these, 28 measurements totalling 596 m of cumulative ice thickness, were made along a 160 m long profile perpendicular to the ridge. The maximum ice thickness measured along the profile was 30.2 m, of which 26.2 m was the keel. Based on drilling rates achieved, 900 m to 1,800 m of ice can be drilled per day depending upon the ice thickness, sampling frequency, and number of relocations required.