Lake tsunamis represent an underrecognized but potentially devastating natural hazard for growing lakeside populations, infrastructure, and cultural heritage. In lacustrine environments, the combination of steep slopes, human-driven sediment input, and active tectonics makes lakes especially vulnerable to mass movements or delta collapses triggered by earthquakes or occurring spontaneously. Mass-wasting deposits (MWDs) in lakes have long been used as palaeoseismic archives, but their associated tsunami hazards remain poorly understood. This thesis advances the study of lake tsunamis by integrating numerical modelling with sedimentological, palaeoseismological, historical, and archaeological records to reconstruct past events and improve hazard assessments.
In this talk, four study sites (Lake Aiguebelette, Lake Bourget, Lake Iseo, and Lake Iznik) were prioritized based on geophysical and geological observations, enabling responses to different types of geodynamic contexts. A novel numerical model was developed that couples landslide dynamics, co-seismic deformation, and seismic wave propagation with both hydrostatic and dispersive tsunami models to capture the complete cycle of earthquake-landslide-induced tsunamis. This approach not only takes into account the combined effects of earthquakes and landslides in generating tsunami waves but also simulates basin-wide seiches excited by seismic shaking. We further demonstrate how seiche waves can interact with turbidites to form homogeneous layers and provide a framework to distinguish seismic from non-seismic triggers of megaturbidites. We also quantify dispersive effects in subaqueous landslideinduced tsunamis in closed lakes.