3D Seismic Imaging of a Deep Landslide in the Eastern Alps (Northern Italy)

The Lamosano Town in the Eastern Alps, was built on the top of a ridge, involved in a slow landslide movement that caused several damages to various buildings. Former studies, conducted in the early eighties, suggested of classify the town as a centre to be relocated. The Italian Government recently funded a new investigation program aimed to better understand the landslide dynamics and assess the possibility of mitigating the surface effects avoiding the need of transferring part of the local population to a different site. In this context was undertaken an integrated 3D seismic refraction tomography / reflection survey targeting the geological structure of the ridge. The subsurface below the ridge was clearly imaged by the seismic and the major contacts between the different units were resolved with an adequate degree of horizontal and vertical resolution. The high-resolution acoustic image of the subsurface led to the formulation of new hypotheses about the major cause of the soil movements and the possible relationship between groundwater circulation and surface displacements. 3D high-resolution seismic imaging proved to be very effective in the characterisation of areas affected by deep landslide phenomena.