GNGTS 2017 - 36° Convegno Nazionale

572 GNGTS 2017 S essione 3.1 Acknowledgements The work was carried out in the frame of the IMAGE Project (FP7, grant agreement No. 608553). Part of the study was developed in the frame of the PhD program at the Politecnico di Torino. We thank the fieldwork team. References Batini F., Fiordelisi A., Graziano F., Toksöz M.N.; 1995: Earthquake Tomography in the Larderello Geothermal Area , in: Proceedings of the World Geothermal Congress, 1995-2, 817-820. Capozzoli L., De Martino G., Giampaolo V., Godio A., Manzella A., Perciante F., Rizzo E., Santilano A.; 2016: Deep electrical resistivity model of the Larderello geothermal field (Italy): preliminary results of the FP7 IMAGE experiment . Abstract, GNGTS 2016, Lecce Dini A., Gianelli G., Puxeddu M., Ruggieri G.; 2005: Origin and evolution of Pliocene–Pleistocene granites from the Larderello geothermal field (Tuscan Magmatic Province, Italy) , Lithos, 81 , 1-31, doi:10.1016/ j.lithos.2004.09.002. Godio A., Massarotto A., Santilano A; 2016: Particle Swarm Optimisation of Electromagnetic Soundings . Proceeding of Near surface geoscience 2016, Barcellona, Spain DOI. 10.3997/2214-4609.201602024. 1-4. Rodi W. and Mackie R.L.; 2001: Nonlinear conjugate gradients algorithm for 2-D magnetotelluric inversion . Geophysics, 66 , 174-187 Santilano A., Manzella A., Gianelli G., Donato A., Gola G., Nardini I., Trumpy E., Botteghi S.; 2015: Convective, Intrusive Geothermal Plays: what about tectonics? Geothermal Energy Science , 3 , 51-59. doi:10.5194/gtes-3- 51-2015 Santilano A.; 2017: Deep geothermal exploration by means of electromagnetic methods: New insights from the Larderello geothermal field (Italy) . PhD Thesis. Politecnico di Torino (Italy). 3-D BASIN GEOMETRY RECONSTRUCTION AND ACTIVE NORMAL-FAULT CHARACTERIZATION USING GEOPHYSICAL DATA IN THE CENTRAL APPENINES, ITALY V. Sapia, R. Civico, V. Fabio Istituto Nazionale di Geofisica e Vulcanologia, Rome, Italy Introduction. The central Apennines of Italy are one of the most seismically active areas in the Mediterranean region, as highlighted by the occurrence of repeated moderate to strong earthquakes occurred in the in the past twenty years (Colfiorito 1997, L’Aquila 2009, Amatrice- Visso-Norcia 2016) and in historical times. Here, a large number of active normal-faults accommodate the present-day extension affecting the chain, and play a primary role in shaping the landscape and in controlling the evolution and the geometry of several intermontane basins (e.g., the Gubbio, Norcia, L’Aquila, Castelluccio, Sulmona, and Fucino basins). Due to their favourable morphological conditions, these basins are seat of dense urbanization. The closeness of these developments to active, seismogenic faults causes a high exposure to seismic risk for tens of thousands of people, industrial centres and invaluable historical/cultural heritage sites. Among other factors, a key element that may help to mitigate the seismic risk and allow sustainable use of the territory is the assessment of the local geological and geotechnical characteristics that have an impact on seismic ground motion and their amplifications. As such, the characterization of the infill thickness in addition to the imaging at depth of the basin and the subsurface faults geometry are crucial for scenario-based seismic hazard analyses. In Italy, the knowledge of active and potential seismogenic faults is often restricted so far to surface geological and morphological surveys corroborated with paleoseismological studies. However, these types of information are limited to a) a restricted number of survey sites for each fault system, b) a depth of investigation of only a few meters. This explains the need to integrate surface knowledge with subsurface data using geophysical investigations.