The application of geophysics in reconstructing past Antarctic ice masses, their dynamics and hydrology

Studies using geophysical techniques have contributed to knowledge of past Antarctic ice masses in a variety of ways. Here we review how geophysical results have helped constrain past ice extents, glacial sediment depocentre locations, the dynamic behaviour of formerly more extensive ice sheets, their basal hydrology, and different styles of retreat. Geophysical methods employed include multibeam echo sounding, sidescan sonar imaging, seismic reflection profiling, sub-bottom acoustic profiling, measurement of physical properties on sediment cores, interpretation of gravity anomalies from shipboard surveys and inversion of satellite altimetry data, and outcrop-scale investigations using a remotely operated vehicle. We consider, however, that the best way to reconstruct past ice masses is to use geophysical methods as part of a multidisciplinary approach. To produce robust reconstructions geophysicists must work closely with marine geologists, geomorphologists, terrestrial Quaternary geologists, ice core researchers, ice sheet modellers, glacial isostatic adjustment modellers and biologists. An important challenge for the future is to integrate insights from past ice sheet changes into ice sheet models, and thus improve constraints on the contribution Antarctic ice sheets will make to sea-level rise in a warming climate