Spectral analysis has been applied to 940 kilometers of under-ice thickness data recorded by the USS QUEENFISH in the Canada Basin, August 1970. Periodicities of 50--150 m most commonly occurred throughout the track, with longer wavelengths common in areas of thicker, more variable ice. While some regional variations could be discerned, unique regional patterns were not apparent, supporting the hypothesis that ice characteristics in this region are relatively homogeneous. ¿ American Geophysical Union 1988