Numerical modeling of the tipping processes of ice detachment: a case study of Sedongpu Glacier in the Southeastern Tibetan Plateau

Abstract. Glacier detachment is a severe natural hazard that can cause enormous damage in downstream regions. During the detachment, glacier will experience an abrupt change from slow-moving to high-speed flow in just a few minutes. In this study, we investigate a massive glacier detachment event occurred in 2018 at the Sedongpu valley, Southeastern Tibet, using a two-dimensional first-order ice flow model by introducing an ice stiffness and basal slip positive feedback mechanism. In this model approach, ice detachment can be triggered if ice stress exceeds the initial yield strength of the glacier. By including this tipping mechanism, we simulate the abrupt changes in the ice flow pattern for the Sedongpu glacier. The transition process from slow to abrupt flow can occur within just several model time steps. The modeled duration time of the 2018 Sedongpu detachment is comparable with observation. The abrupt weakening of ice strength from elastic to plastic deformation may be one of the main causes of the tipping processes of glacier detachment. This numerical model approach could possibly be used for early warnings of glacier detachment hazards in the surrounding regions of the Sedongpu valley.