Urban seismic noise characterization at the Verona Arena, Italy

The Arena of Verona is a Roman amphitheater built in the first century AD. It is a remarkable example of the historical architecture and cultural heritage of Italy. With an elliptical structure measuring approximately 150 meters in length and 120 meters in width, it remains one of the largest and best-preserved amphitheaters of its kind. Located in the center of Verona, the Arena continues to host cultural events that attract thousands of people. To ensure the long-term safety of the structure and decrease risks to visitors, it is important to evaluate its structural integrity and to understand the interaction with the soil. The Arena is surrounded by a densely populated urban environment that generates significant seismic (vibrational) noise. While this poses some challenges for geophysical studies and structural monitoring, it allows for non-invasive characterization using mechanical waves.

In this study, seismic noise was recorded continuously for 7 days by a square 2D seismic array, with side of 18 m and 3 m sensor spacing. The network consisted of 40 1-component and 10 3-component SmartSolo seismic nodes, deployed on the stone floor at the center of the Arena.

Data were processed using passive seismic techniques. First, the frequency content and amplitude distribution of the measured seismic noise over time were investigated. Second, the spatial distribution of the noise sources was derived using one-component beamforming. Third, the shear wave velocity (Vs) profile of the underlying medium was derived using passive seismic interferometry. The Vs profile will be used for seismic risk assessment studies.

 

The present study is being carried out within the framework of the USES2 project, which receives funding from the EUROPEAN RESEARCH EXECUTIVE AGENCY (REA) under the Marie Skłodowska-Curie grant agreement No 101072599.