Deep‐Seated Landslide Stability on Curved Basal Surfaces With and Without Glacier Buttressing

Abstract Glacial retreat influences landslide dynamics, yet the controls on stability and transient acceleration remain unclear. We develop a two‐dimensional mechanical model of landslides with curved basal surfaces, Mohr‐Coulomb friction, and ice buttressing. We define stability as the existence of a feasible equilibrium geometry, where landslide thickness vanishes at both upslope and downslope boundaries. The model reveals a self‐stabilizing mechanism: basal curvature facilitates the mass redistribution necessary to achieve these equilibrium states after ice loss. Stability depends on slope, friction, pore pressure, curvature, and the ice‐to‐rock density ratio. Ice buttressing broadens the range of stable configurations, while its loss drives re‐equilibration or failure. Transient accelerations are expected to emerge naturally as landslides evolve between these equilibrium states. These insights provide a mechanistic basis for anticipating landslide hazards in deglaciating regions, clarifying why some slopes stabilize while others fail following glacier retreat.