GNGTS 2022 - Atti del 40° Convegno Nazionale

148 GNGTS 2022 Sessione 1.3 A GEOLOGICAL REVIEW OF THE GARGANO PROMONTORY (SOUTHERN ITALY) WITH SEISMIC AND GEODETIC DATA S. Miccolis 1 , M.M.C. Carafa 2 , M. Filippucci 1 , J.P. Merryman Boncori 3 , A. Tallarico 1 1 Dipartimento di Scienze della Terra e Geoambientali, Università degli Studi di Bari Aldo Moro, Bari, Italia 2 Sezione di Sismologia e Tettonofisica, Istituto Nazionale di Geofisica e Vulcanologia, L’Aquila, Italia 3 DTU Space Institute, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark Understanding the active tectonic processes is fundamental for mitigating the seismic risk, though the actual limit of applied methodologies. Among the Italian areas still requiring further investigations, the Gargano Promontory (hereafter GP), in Southern Italy, represents a peculiar case. It has been recognized that the GP belongs to the Adriatic plate and that it consists of a carbonate-dolomitic succession with localized internal deformations. It is also known that strong earthquakes struck this area. Recent seismicity characterized by a constant low energy activity confirms the active deformation of the area, but its association with the active faults remains scarcely investigated and still debated. For this reason, we have investigated the GP seismicity through different approaches to increase the seismotectonic understanding of this area. Relying on OTRIONS local seismic network (Tallarico, 2013), installed by the University of Bari Aldo Moro in cooperation with the National Institute of Geophysics and Volcanology), all the recorded events since 2013 were re-analyzed, providing a new seismic database of 635 microearthquakes used to retrieve focal mechanisms and the actual stress field of the GP (Miccolis et al. , 2021). Then, thanks to a collaboration with the Technical University of Denmark, we included in this study the Persistent Scatterers InSAR analysis (Ferretti et al. , 2001) to explore possible deformation patterns and observe the area’s tectonic signal. According to the results, a 40 km thick seismogenic layer has been identified with maximum earthquake frequency between 14 and 37 km deep, with prevalent compressive and transpressive kinematics. Moreover, a deep surface trending SW-NE and dipping towards NNW was observed and considered the most likely responsible for the observed seismicity. The integrated use of geodetic survey highlights a general uplift along the whole area, with low to very low rates, and large subsiding sector S of the GP most likely due to the excessive water extraction. However, it was impossible to detect a tectonic signal, which was hidden by a short-term and anthropic signal, and to observe localized displacements along specific structures. These observations confirm the large amount of bulk deformation observed with the GPS, E to the Apennines chain. References Ferretti, A., Prati, C., Rocca, F., 2001. Permanent scatterers in SAR interferometry . IEEE Trans. Geosci. Remote Sens. 39, 8–20. https://doi.org/10.1109/36.898661 Miccolis, S., Filippucci, M., de Lorenzo, S., Frepoli, A., Pierri, P., Tallarico, A., 2021. Seismogenic Structure Orientation and Stress Field of the Gargano Promontory (Southern Italy) From Microseismicity Analysis . Front. Earth Sci. 9, 589332. https://doi.org/10.3389/feart.2021.589332 Tallarico, A., 2013. OTRIONS Project. URL http://www.otrions. uniba.it/