Debris flows composed of diamictic glacial sediment are found on the continental slope offshore of many former ice streams in the Arctic and Antarctic. They are often stacked, making up important building blocks of the major trough-mouth fans that form huge depocentres on high-latitude margins (e.g. Laberg & Vorren 1995; King et al. 1996; Taylor et al. 2002). Such debris flows have been investigated previously using 2D-seismic methods and have also been mapped in plan using side-scan sonar and multibeam systems (e.g. Dowdeswell et al. 1996; Nygård et al. 2002; Pedrosa et al. 2011). Three-dimensional-seismic data can be used to image and map these and other glacigenic landforms buried within Quaternary sediments (e.g. Dowdeswell & Ottesen 2013).