GNGTS 2018 - 37° Convegno Nazionale

108 GNGTS 2018 S essione 1.1 Di Luccio F., Chiodini G., Caliro S., Cardellini C., Convertito V., Pino N.A., Tolomei C., Ventura G.; 2018: Seismic signature of active intrusions in mountain chains . Science Advances, 4.1. Ekstrom G.; 1994: Teleseismic analysis of the 1990 and 1991 earthquakes near Potenza . Annals of Geophysics, 37.6. Ferranti L., Milano G., Burrato P., Palano M., Cannav F.; 2015: The seismogenic structure of the 2013-2014 Matese seismic sequences, Souhern Italy: implication for the geometry of the Apennines active extensional belt . Geophysical Journal International, 201 (2), 823-837. Frepoli A., Cimini G.B., De Gori P., De Luca G., Marchetti A., Monna S., Montuori C., Pagliuca N.M.; 2017: Seismic sequences and swarms in the Latium-Abruzzo-Molise Apennines (Central Italy): new observations and analysis from a dense monitoring of the recent activity . Tectonophysics, 712-713, 312-329. Lahr J.C.; 1989: HYPOELLIPSE: a computer program for determining local earthquake hypocentral parameters, magnitude and first-motion pattern . Y2K Compliant Version. US Department of the Interior, US Geological Survey. Waldhauser F., Ellsworth W.L.; 2000: A double-difference earthquake location algorithm: Method and application to the northern Hayward fault , California. Bulletin of the Seismological Society of America, 90(6), 1353-1368. REVISED RUPTURE GEOMETRY OF THE 30 OCTOBER 2016 MW 6.6 MT. VETTORE-MT. BOVE EARTHQUAKE IN CENTRAL ITALY D. Cheloni, E. Falcucci, S. Gori Centro Nazionale Terremoti, Istituto Nazionale di Geofisica e Vulcanologia, Rome, Italy During major earthquakes, complex fault networks made up of different fault segments can be involved in the rupture process. In this context, the increasing availability of surface deformation measurements obtained by analysis of modern geodetic data have significantly improved the definition of earthquake source geometries, offering the opportunity to develop complex geometric models of earthquake ruptures. However, due to trade-offs between model parameters and to the intrinsically non-unique geodetic inversion solutions, complex multi-fault models supposed only basing on the minimization of the residuals of a certain mathematical model are not a “guarantee” of a real analysis of the fault network associated with the considered seismic event. Therefore, to better define the geometry of an active fault network, it is essential to consider other independent information, as, for example, aftershock distribution, surface rupture and long-term geology. The 30 October 2016 Mw 6.6 Mt. Vettore-Mt. Bove earthquake is the mainshock of the seismic sequence that affected central Italy since 24 August 2016 with the Mw 6.2 Amatrice earthquake, followed by the 26 October Mw 5.9 Visso event and then culminated with the Mw 6.6 mainshock. Geological (e.g., Civico et al. , 2018), seismological (e.g., Chiaraluce et al. , 2017) and geodetic (e.g., Cheloni et al. , 2017) studies agreed in attributing the whole sequence to the progressive rupture of the two majors ~NW-SE striking Mt. Vettore-Mt. Bove and Laga Mts. normal fault systems. In addition, in the study area, major NNE-SSW striking faults represent the pre-existing cross-structures with the respect to the trend of the NW-SE striking Quaternary extensional faulting. The interaction between the Quaternary extensional systems and the inherited thrusts (in terms of segmenting the lateral extension of the active normal faults or of a possible active role of the thrust faults) is still under debate (e.g., Pizzi and Galadini, 2009). The surface deformation associated with the 30 October earthquake is quite complicated and many different rupture scenarios have been already invoked to explain geodetic, seismological and surface observations. Moreover, some modelling results show some persistent residuals in the Norcia area and in the southern part of the Castelluccio plain, where the geological study of Pierantoni et al. (2013) mapped antithetic structures on the western side of the Pian Grande