Electrothermal Drill

The Electrothermal Drill (aka Thermal Drill) melts an annulus around the ice cores it collects. It supplements the 4-Inch Drills and can be substituted for the 4-Inch Drill sonde, using the same winching system, for use in ice warmer than about minus 10° C. The drill collects a 76 mm (3-inch) core and has been used to drill to approximately 200-meters. For depths shallower than 30-meters, a simpler tripod assembly for operation of the drill is available and has been used with good success. The sonde is particularly useful in ice close to the pressure melting point, where electromechanical drills are at risk from melting and refreezing of the surrounding ice. The Thermal Drill has performed well in British Columbia, Alaska and in southeastern Greenland. The drill was most recently deployed and used successfully to drill through firn aquifer layers in SE Greenland during spring 2013 and spring 2015.

IDP has one Thermal Drill ready for issue. A new 65-meter water-shedding cable was procured in 2015 to prevent the fibrous cable typically used with the Thermal and 4-Inch Drills from soaking with water in aquifer layers, refreezing and causing issues with travel over the upper sheave on the drill tower. As requested by the IDP Science Advisory Board and the larger science community, IDP began exploring upgrades to the Thermal Drill in PY 2018 to allow for coring to 300 meters. Initial upgrades are now complete and include new heat rings, a new 300 m water-shedding cable, a magnetic tool to aid in core removal and a prototype ethanol delivery mechanism. Preliminary testing of the upgrades was conducted in March 2019 near Madison. The upgrades will be further tested by IDP in Alaska in July 2019 in conjunction with the Juneau Icefield Research Program (JIRP).