Glacial Ice Cliffs May Collapse in Bursts, New Study Finds

A satellite‑based study by MIT‑Woods Hole researchers shows that the world’s tallest glacial ice cliffs, such as those at Greenland’s Thrym glacier and Antarctica’s Thwaites, have not yet experienced the rapid, runaway collapse scientists feared. The team found that the risk of such collapse hinges on two factors: how steeply the sea floor deepens beneath the ice and how quickly the ice flows toward the ocean. Even when glaciers retreat faster than earlier models predicted, the ice can thin at the edges, lowering cliff height and potentially preventing a catastrophic cascade. However, as buttressing ridges erode, the bed may become too deep for the ice to remain stable, raising the possibility of future sudden collapse and a significant rise in sea level. The study underscores the uncertainty in long‑term sea‑level projections and the need for continued observation.