S-wave velocities for shaking forecast in urban basins

The project S-wave velocities for shaking forecast in urban basins investigates the effect of seismic waves passing through soft rock layers and predicts the ground movement and shaking hazard from real quakes. Densely populated areas are generally settled on flat terrains and close to rivers; these areas are geologically identified as sedimentary basins, due to the fact that they are made of soft layers of sediments. After the occurrence of an earthquake, the seismic waves that enter sedimentary basins will become further amplified in relation to the presence of such soft shallow layers. Therefore these areas are subject to significant potential shake damaging after the occurrence of earthquakes even when they are of low or moderate intensity. This project studies the seismic properties of two sedimentary basins (The Po Plain in Italy, and the Vienna Basin, in Austria) hosting large urban areas and commercial districts, which are subject of high risk of damage and might experience great economical and human loss, when hit by seismicity. The project uses the records of earthquakes occurred worldwide and far away from the study areas, for constructing high-resolution 3D models of these basins, and giving information on their seismic properties. These 3D models are employed for forecasting the amplification of the ground motion that occurs after the occurrence of earthquakes that can happen in or at the borders of the basins, and which are expected to cause the larger shaking within the basins. The results have impact for preparing the community foreseeing the effect of events that might hit urbanized areas even when they are considered having a low probability of occurrence, and give guidelines for disaster risk reduction and protection of cultural heritage.