A Seabed Drumlin Field on the Inner Scotian Shelf, Canada

The interpretation of offshore glacial landforms is difficult using conventional marine geological survey tools. Multibeam bathymetric data offers new opportunities for recognition and interpretation, and has been collected on the Scotian Shelf, by the Canadian Hydrographic Service (Figure 1). A Simrad EM 1000 mapping system [Loncarevic et al., 1994] was used to produce shadowgram images. Elliptical and linear-shaped relief elements occur on the image (Figure 2b), which are similar in shape to a nearby land field of drumlins (Lunenberg Drumlin Field, Figure 2a). The seabed features are interpreted as drumlins and are elongated in a northwest-southeast direction with their steepest sides facing the northwest, and are overlain by two to five metre high ridges (Figure 2b and d), interpreted as linear moraines. The ridges bifurcate, are discontinuous, and vary in both width and height along their length.