Grounding-zone wedges (GZWs) are asymmetrical depocentres built up beneath the grounding-zone of marine-terminating ice streams and fast-flowing outlet glaciers through the delivery of soft, deforming subglacial till from up-glacier. They are typically tens of metres thick, tens of kilometres in length and usually form subdued transverse-to-flow ridges across the long-axes of fjords and troughs on high-latitude continental shelves (e.g. Shipp et al. 1999; Dowdeswell & Fugelli 2012; Batchelor & Dowdeswell 2014). The ridges, representing the relatively steeper ice-distal face of the wedge, usually appear as small scarps or steps in multibeam imagery. The wedges thin in an iceproximal direction, often becoming difficult to identify except by using acoustic-stratigraphic methods.