An experimental tunnel, 300 x 9 ft. was driven into a glacial till hillside near Camp TUTO during the summer of 1959 for the purposes of determining the feasibility of excavating subsurface openings in frozen glacial till, developing efficient methods for excavating this material, and determining the characteristics of the glacial till at depth. Excavation of frozen glacial till by conventional hard-rock mining methods, modified slightly to allow for low temperatures, was found to be feasible. The employment, effectiveness, and possible improvement of the mining methods and equipment are discussed and problems for future study are suggested.

During the 1960 field season, the permafrost tunnel, begun in 1959 in the Tuto area in Greenland, was extended to 605 ft and three rooms were excavated off the main drift. Mining methods and equipment are described and evaluated. The action of explosives on permafrost was investigated and various types of powder are evaluated. The use of advantages provided by the cold environment was demonstrated. A new building material permacrete, was successfully used and its application demonstrated. The glaciology of the region is re-examined in the light of evidence revealed by excavation. It is concluded that permafrost provides a safe underground shelter and that permacrete presents a most suitable material for fortification. (Author).

A mechanical method of tunneling in permafrost was investigated by excavating the Alaska Experimental Permafrost Tunnel in a perennially frozen stratum of Fairbanks silt at the edge of a gold dredge field 11 miles north of Fairbanks. The tunnel is 360 ft long and about 7 x 13 ft in cross section. It was cut by the Alkirk continuous cyclic mining method. Certain properties of the frozen silt were investigated and the tunnel was evaluated as a shelter for military purposes. Temperatures, mechanical compositions and moisture contents are discussed and observations on plastic deformation are given. The machine uses a pilot-pull principle to provide face pressure. Its potential performance was evaluated. Special observations of cutting strain and power consumption were performed and the cutting process was analyzed. It was found that the mechanical process is expedient and that with modifications the Alkirk principle promises to become a feasible method of excavating deep shelters in permafrost. Subsurface shelters in permafrost provide advantageous protection against high velocity shocks. The operations' efficiency is analyzed in the appendix.

Paul Bierman’s realization that Greenland’s ice sheet melted when Earth was no warmer than today sounds an alarm for our planet. In 2018, lumps of frozen soil, collected from the bottom of the world’s first deep ice core and lost for decades, reappeared in Denmark. When geologist Paul Bierman and his team first melted a piece of this unique material, they were shocked to find perfectly preserved leaves, twigs, and moss. That observation led them to a startling discovery: Greenland’s ice sheet had melted naturally before, about 400,000 years ago. The remote island’s ice was far more fragile than scientists had realized—unstable even without human interference. In When the Ice Is Gone, Bierman traces the story of this extraordinary finding, revealing how it radically changes our understanding of the Earth and its climate. A longtime researcher in Greenland, he begins with a brief history of the island, both human and geological, explaining how over the last century scientists have learned to read the historical record in ice, deciphering when volcanoes exploded and humans started driving cars fueled by leaded gasoline. For the origins of ice coring, Bierman brings us to Camp Century, a U.S. military base built inside Greenland’s ice sheet, where engineers first drilled through mile-thick ice and into the frozen soil beneath. Decades later, a few feet of that long-frozen earth would reveal its secrets—ancient warmth and melted ice. Changes in Greenland reverberate around the world, with ice melting high in the arctic affecting people everywhere. Bierman explores how losing Greenland’s ice will catalyze devastating events if we don’t change course and address climate change now.

1919/28 cumulation includes material previously issued in the 1919/20-1935/36 issues and also material not published separately for 1927/28. 1929/39 cumulation includes material previously issued in the 1929/30-1935/36 issues and also material for 1937-39 not published separately.