The future fate of the Antarctic ice sheet under a warming climate is dynamically tied to geometric changes of the floating ice shelves. The reason is that ice shelves transmit buttressing to upstream regions. Sources for buttressing are shearing at lateral confinements and positions where the ice shelf locally runs aground, such as at ice rises and ice rumples. As Antarctic ice shelves are known to be thinning at increasing rates, their buttressing potential is expected to reduce. Under continuous atmospheric warming over t he Antarctic Peninsula, vast ice-shelf areas have already be en lost. Before break-up, ice shelves accommodated a certain gradual recession of the ice front. During this recession, a transition of the calving front was observed from being convex to be coming concave, reaching either further or less out into the ocean between any anchor points. After break-up, the extant glacier fronts were no longer buttressed and tributary glaciers accelerated with, in places, an eightfold velocity increase. This had direct consequences for ice flowing over the boundary between grounded and floating ice—that is, the ice discharge over the grounding line. More than one decade after the major break-up events on the Antarctic Peninsula, glaciers still adjust to these past perturbations.