GNGTS 2024 - Atti del 42° Convegno Nazionale

Session 3.2 GNGTS 2024 Combined 3D surface wave and refracton analysis around the Scrovegni Chapel in Padua, Italy I. Barone 1 , M. Pavoni 1 , J. T. F. Ting 1 , J. Boaga 1,3 , G. Cassiani 1,3 , D. Dupuy 4 , R. Deiana 2,3 1 Università degli Studi di Padova, Dipartmento di Geoscienze, Padova 2 Università degli Studi di Padova, Dipartmento dei Beni Culturali, Padova 3 Università degli Studi di Padova, Centro Interdipartmentale di Ricerca Studio e Conservazione dei Beni Archeologici, Architetonici e Storico-Artstci (CIBA), Padova 4 Geo2x SA, Yverdon-les-Bains, Svizzera The Scrovegni Chapel in Padua (Italy) is part of the Padua UNESCO World Heritage site since 2021. The chapel hosts a worldwide famous fresco cycle of Gioto datng back to the 14 th century, and it is located in a complex archaeological area hostng remains of several periods. In partcular, the façade of the chapel stands on the remains of the elliptcal middle wall of a Roman amphitheatre. Many aspects are stll unclear, especially regarding the interconnecton between the two monuments and the presence of buried radial walls of the amphitheatre in that area (Deiana et al., 2018). Following the previous studies from Barone et al. 2022 and Barone et al. 2023, a new actve seismic data acquisiton has been carried out using 28 source locatons and 188 seismic nodes, placed all around the chapel on a regular grid of 3 m spacing in both spatal directons (Fig. 1). The new survey area partally overlaps the previously investgated areas. The source used is a weight drop with a 50 kg mass falling from a height of approximately 2 m. Each shot was repeated twice to increase the signal-to-noise rato. A combinaton of single-component (1C) and three-component (3C) nodes was used. Although only the vertcal component was considered for the analyses described hereinafer, the 3C recordings were used to study the seismic waves elliptcity. The same shot records have been analysed with two diferent methods: surface wave tomography and frst arrival traveltme tomography. As for the surface wave analysis, the same procedure used in Barone et al. 2022 was used, including: preliminary analysis for modes identfcaton, pseudo 2D f-k fltering to remove higher-modes and backscatering, phase unwrapping, traveltme extracton and Eikonal tomography (Lin et al. 2009). The outcome of this procedure consists in a series of phase velocity maps, each referring to a diferent frequency of analysis between 10 Hz and 50 Hz. Autospectrum gradient maps were also computed, which refect sudden amplitude changes due to abrupt lateral velocity variatons.