Abstract Seven seismic refraction profiles were completed in 1961 in the Canadian Arctic Islands under the Polar Continental Shelf Project of the Department of Mines and Technical Surveys. These seven profiles were shot along a line extending from a location 30 miles north of Ellef Ringnes Island, along the west coast of this same island to a point 30 miles south of the island into Belcher Channel. The program was carried out using an S-SS helicopter with the supply support and major moves by Otter fixed-wing aircraft. Dynamite charges were successfully detonated in depths of water to 1,285 ft without the use of “boosters.” A Decca Survey Chain provided regional navigation but this system is not sufficiently accurate for long-range seismic refraction surveying. These seven profiles are presented in a cross section across the Sverdrup Basin, correlated by seismic velocities, indicating a thickness of approximately 40,000 ft of sediment in the center of the Basin to a formation with a horizontal velocity of 20,000 ft/sec “Basement” or the base of the unmetamorphosed sediments may be 64,000 ft deep at this location.