Portions of ice sheets grounded deep beneath sea level can disintegrate if tall ice cliffs at the ice-ocean boundary start to collapse under their own weight. This process, called marine ice cliff instability, could lead to catastrophic retreat of sections of West Antarctica on decadal-to-century time scales. Here we use a model that resolves flow and failure of ice to show that dynamic thinning can slow or stabilize cliff retreat, but when ice thickness increases rapidly upstream from the ice cliff, there is a transition to catastrophic collapse. However, even if vulnerable locations like Thwaites Glacier start to collapse, small resistive forces from sea-ice and calved debris can slow down or arrest retreat, reducing the potential for sustained ice sheet collapse.

如果冰海边界处的高冰崖在其自身的重量下开始坍塌，那么深埋在海平面以下的部分冰盖可能会崩解。这一过程被称为海洋冰崖不稳定，可能导致南极洲西部部分地区在十年到世纪的时间尺度上发生灾难性的后退。在这里，我们使用一个解决冰流动和破坏的模型来表明动态减薄可以减缓或稳定悬崖后退，但是当冰悬崖上游的冰厚度迅速增加时，就会发生向灾难性坍塌的过渡。然而，即使像思韦茨冰川这样脆弱的地方开始崩塌，来自海冰和崩解碎片的小阻力也会减缓或阻止撤退，从而降低冰盖持续崩塌的可能性。