Hole Liquids

In deep drilling, the hole must be filled with a liquid in order to prevent hole closure from the surrounding ice. The maximum depth received in a dry hole is 906 m at Dome C using a thermal drill in ice with a temperature of -50° C (Ritz and others, 1982). In Greenland, a thermal auger reached 404 m in -30° C ice (Clausen and others, 1988). Mechanical drills have a more limited depth capability in a dry hole than a thermal drill due to the lack of clearance at the drill head. Nevertheless, it was possible to core 360 m at South Pole (-55° C) and 325 m at Renland in East Greenland (-18° C). In deeper drillings, the hole has to be filled with a liquid.