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The recently published Bedmap2 datasets mark the culmination of several decades of subice and subocean Antarctic topographic surveying by many nations, but maps of the topographic data distribution show that in the global context, the Antarctic bed remains very poorly sampled. Most of the remaining large unmapped areas on Earth lie under Antarctic ice and polar surveying continues to be difficult and expensive, thus it is important to identify where future efforts should be concentrated. A survey of 75 experts in various aspects of polar science shows that a lack of adequate topographic data is an important constraint in several themes, but the data gaps and the data needs do not tend to coincide. There is strong demand for higher resolution surveying in previously visited areas, particularly in the most dynamic and most rapidly changing regions as identified by glaciologists, oceanographers, hydrologists, biologists and geomorphologists, while geologists and ice core scientists focus on the most important areas for understanding Antarctica over deeper time. The data requirements identified here could be addressed for most areas given sufficient time and funding, but the technology needed to survey the interiors of the large ice shelf cavities has only just been developed. [ABSTRACT FROM AUTHOR]

This review presents a perspective on recent trends in glacial geomorphological research, which has seen an increasing engagement with investigating glaciation over larger and longer timescales facilitated by advances in remote sensing and numerical modelling. Remote sensing has enabled the visualization of deglaciated landscapes and glacial landform assemblages across continental scales, from which hypotheses of millennial-scale glacial landscape evolution and associations of landforms with palaeo-ice streams have been developed. To test these ideas rigorously, the related goal of imaging comparable subglacial landscapes and landforms beneath contemporary ice masses is being addressed through the application of radar and seismic technologies. Focusing on the West Antarctic Ice Sheet, we review progress to date in achieving this goal, and the use of radar and seismic imaging to assess: (1) subglacial bed morphology and roughness; (2) subglacial bed reflectivity; and (3) subglacial sediment properties. Numerical modelling, now the primary modus operandi of 'glaciologists' investigating the dynamics of modern ice sheets, offers significant potential for testing 'glacial geomorphological' hypotheses of continental glacial landscape evolution and smaller-scale landform development, and some recent examples of such an approach are presented. We close by identifying some future challenges in glacial geomorphology, which include: (1) embracing numerical modelling as a framework for testing hypotheses of glacial landform and landscape development; (2) identifying analogues beneath modern ice sheets for landscapes and landforms observed across deglaciated terrains; (3) repeat-surveying dynamic subglacial landforms to assess scales of formation and evolution; and (4) applying glacial geomorphological expertise more fully to extraterrestrial cryospheres. [ABSTRACT FROM AUTHOR]

The Amundsen Sea sector of West Antarctica has the potential to contribute significantly to sea-level change. We calculate century-long probabilistic forecasts of sea-level contribution for different melt scenarios over the coming century. We use the state-of-the-art WAVI ice-sheet model with realistic initial conditions to investigate the sensitivity of this region to prescribed basal melting, varying both the basal melt rate under newly formed cavities and the initialised melt rate under existing cavities. Previously 'unresolved' ice rises with non-zero drag on the shelves are required to match the surface observations, and we explore the effect of either partially or fully removing this drag at the start of the run. Present-day climate and calving fronts are prescribed throughout the runs. We then use Bayesian methods together with mass balance data over the first decade of the model run to constrain predictions of sea-level contribution over the 21st Century, giving precedence to parameter combinations that best match the mass balance data. Our probabilistic approach reduces uncertainty in future predictions of sea-level contribution for different melt scenarios, but as the results are very sensitive to the prescribed basal melt, a method to calculate melt rates is key to providing more robust predictions. [ABSTRACT FROM AUTHOR]