History of ice drilling
He planned to make temperature observations on the glacier's interior, and brought an iron drilling rod, 25 feet (7.6 m) long, for that purpose.
After heavy rain overnight, the drilling became much faster: a foot (30 cm) of progress was made in less than fifteen minutes, and the hole eventually reached a depth of 20 feet (6.1 m).
Agassiz drilled deeper holes, and planted six stakes in a straight line across the glacier, taking measurements with reference to identifiable points on the surrounding mountains to ensure that he would be able to tell if they had moved.
[11] Agassiz's demonstration of the great difficulty of drilling deep holes in glacier ice discouraged other researchers from further efforts in this direction.
Blümcke and Hess attempted to run casing pipe down through the cavity, so that the water and cuttings could continue to come up to the surface, but this was unsuccessful, and would have been too expensive a solution to implement every time the problem occurred.
[19] In 1899 the bed of the glacier was reached in two places, with depths of 66 m and 85 m, and this success persuaded the German and Austrian Alpine Club, which had subsidized the early expeditions, to fund ongoing work and build an improved version of the drilling apparatus, which became available in 1901.
[21][note 2] In a review of Blümcke and Hess's work published in 1905, Paul Mercanton suggested that a petrol engine to power both the rotation of the drill and the water pump would be natural improvements.
A new rod weighing 40 kg was forged in Chamonix, which brought the speed back up to 2.8 m per hour, but at 25 m the drill bit stuck in the hole near the bottom.
[12][25] Constant Dutoit and Paul-Louis Mercanton carried out experiments on the Trient Glacier in 1900, in response to a problem posed by the Swiss Society of Natural Sciences in 1899 for their annual Prix Schläfli, a scientific prize.
Research continued into drilling deeper holes; partly for scientific reasons, such as understanding glacier motion, but also for practical ends.
[47] In 1938, Gerald Seligman, Tom Hughes, and Max Perutz visited the Jungfraujoch to take temperature readings; their goal was to study the transition of snow into firn and then into ice with increasing depth.
They dug shafts as deep as 20 m by hand, and also bored holes with augers of two different designs, including one based on advice provided by Hans Ahlmann.
Perutz returned with the new drill tip to find that his two graduate students, whom he had left learning to ski while he went to Bern, had both broken their legs.
The goal of expedition was to measure the temperature of the glacier at various depths below the surface, and an electrothermal drill was used to create the boreholes where the thermometers were deployed.
In the summer of 1949 Ract-Madoux and Reynaud returned to the glacier with a thermal drill consisting of a 1 m long resistor wound in a cone shape, with a maximum diameter of 50 mm.
[55][41] In the summer of 1951 Robert Sharp of the California Institute of Technology duplicated Perutz's glacial flow experiment, using a thermal drill with a hotpoint tip, on the Malaspina Glacier in Alaska.
[59] The US Army's Corps of Engineers greatly expanded its activities in Alaska during World War II, and several internal organizations came into being to address the problems they encountered.
[63] The same study also evaluated non-coring auger designs, and determined that a clearance angle of 20° produced a good cutting action with little downward force required.
As with Blümcke and Hess, an air gap that did not allow the water to clear the ice cuttings was fatal to drilling, and usually led to the borehole being abandoned.
The rotary drilling gear included a saw-toothed coring bit, with spiral slots intended to aid the passage of ice cuttings back up the hole.
[53] In 1950 Maynard Miller took rotary drilling equipment weighing over 7 tons to the Taku glacier, and drilled multiple holes, both to investigate glacial flow by placing an aluminium tube in a borehole and measuring the inclination of the tube with depth over time, as Perutz's team had done on the Jungfraufirn, and also to measure temperature and retrieve ice cores, mostly from 150–292 ft deep.
Multiple holes were drilling to the base of the glacier; the lances were also used to clear entire tunnels under the ice, with the equipment adapted to spray the hot water through seventeen nozzles simultaneously.
[90] In the early 1950s Henri Bader, then at the University of Minnesota, became interested in the possibility of using thermal drilling to obtain cores from holes thousands of metres deep.
[93] It was tested from July to September 1959 in Greenland, at Camp Tuto, near Thule Air Base, but only drilled a total of 89 inches in three months.
32.5 ft of aluminium tube was attached behind the drill head, with metal discs of 3.2 inches diameter screwed on at the midpoint and upper end.
The equipment performed well in tests on the Glacier du Géant in the Alps in October 1960, but when drilling began in Antarctica in January 1961, progress was slow and the cores recovered were broken and partly melted.
[101] The drill tests were conducted by the US Navy Civil Engineering Laboratory, and were intended to establish suitable methods for construction work in polar regions.
The project moved to Camp Century from August to December 1960, returning in 1961, when they managed to reach over 535 feet, at which point the drill became stuck.
A test version of the drill was built at CRREL with a 4 in diameter, and was found to quickly return the borehole to vertical when started in a deliberate inclined hole.
[165][166] A drill with a motor and spring attached in such a way as to cause the barrel to vibrate vertically at about 50 Hz was used in the Antarctic in the 1990s at the Russian Vostok station; it proved to be very effective, boring a 6.5 m hole with a typical penetration rate of 6–8 m/min.
