Evaluation of Hot Water Drills

Caused by the increasing geophysical and glaciological field investigations in polar regions more and more drill holes in cold firn and ice are required. Using hot water drilling a fast drill hole production is possible. Existing evaluations for hot water drills were derived from drill tests in temperate ice for small hole diameters. The present paper shows a possibility, based on thermal calculations in ground engineering to evaluate the necessary hear and the drill rate dependent on:

• the hole diameter,
• the firn (ice) density,
• the in-situ temperature of the firn (ice),
• the water flux,
• the water temperature.

For quick estimates some graphs for fixed hole diameters are given.