Meltwater channels that have formed beneath glaciers and ice sheets have been observed on glaciated terrain, both terrestrial and submarine. Around Antarctica, channels incised into bedrock on the inner continental shelf have been found in several cross-shelf troughs that held major ice-streams during the last full-glacial (e.g. Pine Island Trough, Nitsche et al. 2014; Dotson-Getz Trough, Larter et al. 2009). The relatively widespread occurrence of meltwater channels has important implications for enhancing the flow of former ice streams over rough bedrock topography, yet questions remain regarding their timing and mode of formation. Meltwater channels from Marguerite Trough offshore of the western Antarctic Peninsula are described here (Fig. 1a).