Projections of ice sheet behavior hinge on how ice flow velocity evolves and the extent to which marine-based grounding lines are stable. Ice flow and grounding line retreat are variably governed by the coupling between the ice and underlying terrain. We ask to what degree catchment-scale bed characteristics determine ice flow and retreat, drawing on paleo-ice sheet landform imprints from 99 sites on continental shelves worldwide. We find that topographic setting has broadly steered ice flow and that the bed slope favors particular styles of retreat. However, we find exceptions to accepted “rules” of behavior: Regional topographic highs are not always an impediment to fast ice flow, retreat may proceed in a controlled, steady manner on reverse slopes and, unexpectedly, the occurrence of ice streaming is not favored on a particular geological substrate. Furthermore, once grounding line retreat is under way, readvance is rarely observed regardless of regional bed characteristics.

冰盖行为的预测取决于冰流速如何演变以及海基接地线的稳定程度。冰流和地线的后退程度受冰和下层地形之间的耦合影响。我们询问集水规模的河床特征在多大程度上决定了冰的流动和后退，利用了来自全球大陆架上99个站点的古冰片地形印记。我们发现地形环境广泛地控制了冰流，而床坡更倾向于特殊的撤退方式。但是，我们发现了公认的行为“规则”的例外情况：区域地形高点并不总是会阻碍快速冰流，后退可能会以受控，稳定的方式在反向斜坡上进行，并且出乎意料的是，在特定的地质基质上，冰流的发生是不利的。此外，一旦接地线撤退，无论区域床的特征如何，都很少观察到预备情况。