Bed topography of Princess Elizabeth Land in East Antarctica

Abstract. We present a topographic digital elevation model (DEM) for Princess Elizabeth Land (PEL), East Antarctica – the last remaining region in Antarctica to be surveyed by airborne radio-echo sounding (RES) techniques. The DEM covers an area of ~900,000 km2 and was established from new RES data collected by the ICECAP-2 consortium, led by the Polar Research Institute of China, from four campaigns since 2015. Previously, the region (along with Recovery basin elsewhere in East Antarctica) was characterised by an inversion using low resolution satellite gravity data across a large (>200 km wide) data-free zone to generate the Bedmap2 topographic product. We use the mass conservation (MC) method to produce an ice thickness grid across faster-flowing (>30 m yr-1) regions of the ice sheet and streamline diffusion in slower-flowing areas. The resulting ice thickness model is integrated with an ice surface model to build the bed DEM. With the revised bed DEM, we are able to model the flow of subglacial water and assess where the hydraulic pressure, and hydrological routing, is most sensitive to small ice-surface gradient changes. Together with BedMachine Antarctica, and Bedmap2, this new PEL bed DEM completes the first order measurement of subglacial continental Antarctica – an international mission that began around 70 years ago. The ice thickness and bed elevation DEMs of PEL (resolved horizontally at 500 m relative to ice surface elevations obtained from a combination of European Remote Sensing Satellite 1 radar (ERS-1) and Ice, Cloud and Land Elevation Satellite (ICESat) laser satellite altimetry datasets) are accessible from https://doi.org/10.5281/zenodo.3666088 (Cui et 38al., 2020).