GNGTS 2022 - Atti del 40° Convegno Nazionale

32 GNGTS 2022 Sessione 1.1 3D-KERNEL BASED IMAGING OF AN IMPROVED ESTIMATION OF Q C IN THE GARGANO PROMONTORY (SOUTHERN ITALY) M. Filippucci 1 , S. Lucente 1 , E. Del Pezzo 2,3 , S. de Lorenzo 1 , G. Prosser 4 , A. Tallarico 1 1 Department of Earth and Geo-Environmental Science, University of Bari Aldo Moro (UniBa) 2 National Institute of Geophysics and Volcanology (INGV), Osservatorio Vesuviano 3 Instituto Andaluz de Geofisica, Universidad de Granada 4 Department of Science, University of Basilicata (UniBas) We investigated crustal seismic attenuation by the coda quality parameter Qc in the Gargano Promontory (Southern Italy), using a database composed of 191 small earthquakes (1.0 ≤ M L ≤ 2.8) recorded by the local OTRIONS and the Italian INGV seismic networks, over three years of seismic monitoring. The database was recently released by Filippucci et al. (2021a). Following the single back-scattering theoretical assumption (Aki and Chouet, 1975), Qc was computed using different frequencies (in the range of 2-16 Hz) and different lapse times (from 10 to 40 s). Results in Fig. 1 indicate that the trend of Qc  vs. frequency is like that observed in the same area with another dataset (Filippucci et al. , 2019), overlaps the trend obtained for the adjacent Apennine chain (de Lorenzo et al. , 2013) and other tectonic and volcanic regions in Italy (references in Fig. 1). The 3D mapping procedure was based on sensitivity kernels following the procedure described by Del Pezzo and Ibanez (2020). 3D images at different frequencies revealed that the Gargano Promontory is characterized by very low and homogeneous Qc  at low frequencies, and by high and heterogeneous Qc  at high frequencies (Filippucci et al. , 2021b). The lateral variations of Qc at 12 Hz follow the trend of the Moho in this region and are in good agreement with other geophysical observations. Fig. 1 - Comparison between the Qc  estimates for each central frequency  fc  obtained in this work ( t L  = 30 s) and the literature. ( a ) Literature referring to Qc  studies from other areas of Italy (modified from Filippucci et al. , 2019). Letters from A to E refer to the subdivisions of Northeastern Italy by Singh et al. (2001). Acknowledgements This work was partially supported by Project PRIN n. 201743P29 FLUIDS (Detection and tracking of crustal fluid by multi-parametric methodologies and technologies). E.D.P. was partially funded by the Spanish Mineco Project FEMALE, PID2019-106260GB-I00. The computational work has been executed on the IT resources of the ReCaS-Bari data center, which have been