The future contribution of the Antarctic Ice Sheet to sea-level rise is strongly affected by processes that weaken the ice shelves surrounding much of the Antarctic coastline. MOAT investigates basal melting, surface melting, and ice-shelf rheology through radar and photonic sensors, airborne observations, and frequent high-resolution multi-source satellite imagery. The measurements will be used to improve the representation of surface- and basal-melt processes in regional climate and ice-sheet models, helping to reduce uncertainty in projections of Antarctic ice loss and sea-level rise.