This combined session focuses on landslides and large mass movements in rock, debris, and ice, together with other types of ground failure such as liquefaction and subsidence, in settings where seismic activity plays a key role. Observations from recent earthquakes show that impacts are not confined to the coseismic phase, because damaging mass movements can also occur in the post-seismic period due to disturbances caused by earthquakes. These cascading hazards are often treated separately, even though an integrated approach is clearly desirable, and the session provides a forum for researchers and professionals to discuss processes, case histories, and hazard implications across both co-seismic and post-seismic phases.
Large-scale instabilities in rock, weak rocks, debris, and ice represent enormous risks and are complex systems that are difficult to describe, investigate, monitor, and model. Their evolution can range from slow to fast complex mass movements and depends on forcing factors, geological and hydrological boundary conditions, and the evolution in space and time of thermo-hydro-mechanical controls, as well as the properties of the unstable mass. Many aspects remain understudied and debated due to difficult characterization and the limited number of thoroughly studied cases, and regional and temporal distribution and relationships with controlling and triggering factors are often poorly understood, resulting in poor predictions of behaviour and evolution under present and future climates. The session welcomes contributions on case studies, monitoring and modelling approaches and tools, numerical and physical modelling of dynamic loading and instability, deterministic event scenarios and probabilistic evaluations, threshold definition and offline data analyses, advanced numerical modelling and machine learning techniques, innovative dating and investigation methods, site effects such as amplification and the influence of pre-existing landslide masses, and impacts on structures and infrastructures including tunnels, dams, and roads, with the goal of improving hazard assessment and supporting early warning systems.