South Pole–Queen Maud Land Traverse

The South Pole–Queen Maud Land Traverse (SPQMLT) was a three-part scientific exploration of Antarctica undertaken by the United States in the 1960s.

The three parts, referred to individually as South Pole–Queen Maud Land Traverse I, II, and III (SPQMLT-1, -2, and -3), traveled a zigzag route across nearly 4200 km of the Antarctic Plateau in the austral summers of 1964–1965, 1965–1966, and 1967–1968.

Additional fuel and supplies were delivered en route by airdrops from LC-130 aircraft of the U.S. Navy's Operation Deep Freeze.

Every 8 km they paused for simultaneous readings of the altimeters and magnetometers; and for measurements of gravity, surface slope, and snow density, and for weather observations.

The surface slope was measured by scanning the horizon with a theodolite and recording the azimuth and vertical angle of the highest and lowest points.

At Pole of Inaccessibility Station a detailed map was drawn, the existing strain-rate and accumulation-stake networks were measured, and a 5-km accumulation stake line was installed.

The main crevasses were several tens of meters wide, 5 to 7 km long, and oriented approximately east-west.

The crevassed zone is above a major anomaly in the bedrock topography, an abrupt rise of over 1200 m over a horizontal distance of less than 9 km.

From Plateau Station to the turning point, the surface sloped downward with an average gradient of -0.5 to -1 m/km, and became much more negative on the southwest leg of the traverse.

[5][6] The average rate of ice accumulation in the area of the traverse has been estimated at 3.7 g/cm2/yr with a method that involves profiling the radioactivity in the core samples and identifying layers that correspond to a 1955 atmospheric atomic test.