Geophysics in Antarctica: Achievements, Current Capabilities, and Future Directions

Abstract. The Antarctic Ice Sheet (AIS) plays a major role in the global climate, providing a natural laboratory to study the processes that interlink the cryosphere, solid Earth, atmosphere, and hydrosphere. Through its ongoing mass loss, the AIS currently contributes to global-mean sea-level rise at a rate of 0.4 mm/a. However, its impact on and feedback with climate and the details associated with sea-level changes are still poorly understood. To generate more reliable projections for the future, there is an urgent need to substantially improve our knowledge of the solid-Earth properties and subsequent response to ice-mass variations in space and time. This issue has been identified as a key question by the international community, strongly supported by the Scientific Committee on Antarctic Research (SCAR). We review how state-of-the-art Global Navigation Satellite Systems (GNSS) and seismic networks in Antarctica, in combination with further ground-based, airborne and satellite-based geophysical measurements, have been used to significantly advance our understanding of solid-Earth processes and their impact on the cryosphere. Based on these recent achievements, a vision is articulated for science-driven, multidisciplinary geophysical observations and corresponding technological developments. Future research activities should be coordinated to answer the most urgent science questions. For example, how can we consistently test and model, respectively, a realistic mantle rheology, including lateral inhomogeneities and transient relaxation, together with AIS mass changes on all time scales since the last glacial maximum, including Holocene retreat and re-advance? What processes and boundary conditions should coupled ice-sheet / gravity-rotation-deformation models include in order to reflect realistically the complex interaction between the solid Earth, ice sheet and ocean? Long-term observations and improved modelling must be combined to develop precise and reliable projections for Antarctica’s future mass change and associated contribution to sea-level change at both regional and global scales.