Bedrock meltwater channels in Palmer Deep, Antarctic Peninsula

Abstract

The Antarctic Peninsula inner shelf has been deeply scoured by glacial erosion resulting in numerous deep troughs that funnelled ice flow out across the shelf. Palmer Deep is one of these erosional troughs located at the convergence of three distinct ice accumulation centres: Anvers Island, Bruce Plateau and the Graham Coast (Fig. 1a). A distinctive channelized morphology observed in swath-bathymetric data from the trough-outlet sill reflects a combination of subglacial meltwater scour and underlying structural weakness within the bedrock. The origin of these features can be linked to the development of a subglacial lake basin within Palmer Deep during or prior to the Last Glacial Maximum (LGM), its subsequent drainage and the recession of the Palmer Deep ice-stream system (Domack et al. 2006). Fig. 1. Multibeam bathymetry of Palmer Deep collected during NB Palmer cruises NBP9903 and NBP0107 (US Antarctic Program). Aquisition system Seabeam 2100. Frequency 12 kHz. Grid-cell size 50 m. ( a ) Multibeam image. VE×3. Land area from …