Svalbard has about 800 km of ice cliffs where tidewater glaciers reach the sea (Blaszczyk et al. 2009). A number of these glaciers are of surge type (Dowdeswell et al. 1991; Hagen et al. 1993) and have undergone rapid advances of a few years in duration followed by slow retreat over decades, in response to variations in their basal hydrological system driven largely by geometric and thermal changes (e.g. Murray et al. 1998, 2000). These fluctuations, which take place over beds composed mainly of soft sediments, have been monitored using satellite imagery, aerial photographs and early maps (e.g. Ottesen et al. 2008; Flink et al. 2015). The seafloor geomorphology of surging tidewater glaciers in Svalbard, revealed after glacier-terminus retreat, contains a well-defined landform assemblage (e.g. Solheim & Pfirman 1985; Ottesen & Dowdeswell 2006; Ottesen et al. 2008; Flink et al. 2015).