Figure 21. Detailed bathymetric image of smooth-topped, elongate hummocks on the sea floor in the northwestern corner of the study area. We interpret these features to be the eroded remnants of glaciolacustrine deposits covered by a thin layer of mobile sand on the basis of their resistant nature and internal seismic character (Needell and Lewis, 1984). Megaripples can be seen to the south of the glaciolacustrine deposits. Location of image is shown in figure 12.