Ice sheets grounded below sea level are particularly sensitive to climate change due to their direct contact with the changing ocean and other processes that destabilize them. The grounding line, the most seaward position at which the ice is coupled to the bed, is understood to be a potential tipping point of ice sheet stability. Direct observations of the modern grounding lines and the processes that control their behavior are limited. Much of what is known is based on satellite and airborne remote sensing, ice-penetrating radar and seismic surveys, but these methods lack the temporal and spatial resolution needed to understand the range of processes that regulate grounding line behavior. The advent of higher resolution swath bathymetry has yielded detailed images of subglacial and grounding line geomorphologic features formed during the post-LGM retreat of the Antarctic Ice Sheet from the continental shelf. Combined with information derived from strategically placed sediment cores, these geomorphic features record times of ice shelf and grounding line retreat over decadal to century timescales and information about those factors that contributed to grounding line instability.