As part of the PMAP-CASE (Polar Margin Aeromagnetic Program - Circum-Arctic Structural Events) expeditions, two surveys were conducted in consecutive seasons in 1997 and 1998. Cooperating partners were the Department of National Defence (DND), GSC Ottawa and the Institute for Aerospace Research Ottawa (IAR-NRC). The surveys covered the areas of the northern continental margin of Greenland including the northern Nansen Land and western Johannes V. Jensen Land, as well as parts of the Lincoln Sea. The objective of the campaigns was to investigate the structures of the upper crust of the Morris Jesup Plateau and the correlation of magnetic anomalies with known structures and geologic units on land (Franklinian Basin, Kap Washington volcanics, and volcanic dyke swarms). Airborne magnetic surveys (Convair 580) were conducted with a 3 km flight line spacing, and control lines were flown every 30 km. Data were recorded at a constant flight altitude of 300 m above ground. Approximately 30000 km of line data were collected during the two expeditions, covering an area of 73000 km².