Deep shear wave velocity model of the Venice lagoon from seismic noise interferometry

Abstract

To establish a robust reference framework for future seismic hazard evaluations, we introduce the first deep shear wave velocity (Vs) model of the Venice Lagoon (Italy), developed through seismic noise interferometry. A seismometer was deployed in Venice’s historic center, and its continuous noise recordings were cross‑correlated with data from the sole permanent station located on Lido Island. Using seismic noise processing methods and joint inversion of Rayleigh wave group and phase velocity dispersion curves, we obtained a detailed deep Vs profile of the Venice Lagoon subsurface, extending down to the engineering bedrock and the base of the Pliocene sequence. Our model shows strong consistency with geological information from deep boreholes and seismic reflection surveys. Additionally, the determined engineering bedrock depth corresponds well with existing models of the deep alluvial Po Plain from earlier research. This study delivers the first comprehensive deep Vs reference model for Venice, establishing an essential baseline for future seismic response assessments and risk mitigation initiatives designed to safeguard the city’s priceless cultural heritage.