The study presents a high-resolution, digital mosaic of ice motion in Antarctica, compiled from satellite interferometric synthetic-aperture radar data collected during the International Polar Year 2007-2009. The data reveal widespread, patterned, enhanced flow with tributary glaciers extending hundreds to thousands of kilometers inland. This highlights the importance of basal-slip-dominated tributary flow over deformation-dominated ice sheet flow, redefining our understanding of ice sheet dynamics and having significant implications for predicting ice sheet evolution. The study also emphasizes the limitations of traditional methods for measuring ice velocity, such as balance velocity, which assume mass equilibrium and perpendicular ice flow. The new data, obtained through satellite radar interferometry, provide a more accurate and comprehensive picture of ice sheet motion, including the spatial patterns of tributary flow and the influence of bedrock topography on ice movement. The results show that ice velocity ranges from a few cm/year near divides to several km/year on fast-moving glaciers and floating ice shelves, with a bimodal distribution in surface velocity. The study also identifies key areas of rapid flow and highlights the role of subglacial lakes and valleys in facilitating basal slip. The findings challenge previous assumptions about ice sheet flow and suggest that patterned enhanced flow, characterized by a major basal-slip component, is a common feature of ice sheets. The study underscores the importance of understanding ice sheet dynamics for predicting future changes in ice mass balance, especially in a warming climate.The study presents a high-resolution, digital mosaic of ice motion in Antarctica, compiled from satellite interferometric synthetic-aperture radar data collected during the International Polar Year 2007-2009. The data reveal widespread, patterned, enhanced flow with tributary glaciers extending hundreds to thousands of kilometers inland. This highlights the importance of basal-slip-dominated tributary flow over deformation-dominated ice sheet flow, redefining our understanding of ice sheet dynamics and having significant implications for predicting ice sheet evolution. The study also emphasizes the limitations of traditional methods for measuring ice velocity, such as balance velocity, which assume mass equilibrium and perpendicular ice flow. The new data, obtained through satellite radar interferometry, provide a more accurate and comprehensive picture of ice sheet motion, including the spatial patterns of tributary flow and the influence of bedrock topography on ice movement. The results show that ice velocity ranges from a few cm/year near divides to several km/year on fast-moving glaciers and floating ice shelves, with a bimodal distribution in surface velocity. The study also identifies key areas of rapid flow and highlights the role of subglacial lakes and valleys in facilitating basal slip. The findings challenge previous assumptions about ice sheet flow and suggest that patterned enhanced flow, characterized by a major basal-slip component, is a common feature of ice sheets. The study underscores the importance of understanding ice sheet dynamics for predicting future changes in ice mass balance, especially in a warming climate.