GNGTS 2019 - Atti del 38° Convegno Nazionale

88 GNGTS 2019 S essione 1.1 the Central Apennines are likely to interact through time, with switching activity between faults distributed across the strike of the fault system. This can lead to the alternance of phases of earthquake clustering and anti-clustering on single faults located on different flanks of the fault system. Moreover, the results herein presented suggest that more work is needed to understand whether fault scarps in Southern Italy have started to be preserved for time periods older than 15 ± 3 ka. References Beck, J., S. Wolfers, and G. P. Roberts (2018): Bayesian earthquake dating and seismic hazard assessment using chlorine-36 measurements (BED v1), Geosci. Model Dev., 11 (2018), pp. 4383-4397. Bennett, R. A., A. M. Friedrich and K. P. Furlong (2004): Codependent histories of the San Andreas and San Jacinto fault zones from inversion of fault displacement rates. Geology, 32(11), 961-964. Cowie, P.A. and G.P. Roberts (2001): Constraining slip rates and spacings for active normal faults. Journal of Structural Geology, 23(12), pp.1901-1915 https://doi.org/10.1016/S0191-8141 (01)00036-0. Cowie P. A., R. J. Phillips, G. P. Roberts, K. McCaffrey, L. J. J. Zijerveld, L. C. Gregory, J. Faure Walker, L. N. J. Wedmore, T. J. Dunai, S. A. Binnie, S.P. H. T. Freeman, K. Wilcken, R. P. Shanks, R. S. Huismans, I. Papanikolaou, A. M. Michetti and M. Wilkinson (2017): Orogen-scale uplift in the central Italian Apennines drives episodic ehavior of earthquake faults, Nature Sci. Rep. 7., 44858; doi:10.1038/srep44858. Iezzi, F., G. Roberts, J. F. Walker and I. Papanikolaou (2019): Occurrence of partial and total coseismic ruptures of segmented normal fault systems: Insights from the Central Apennines, Italy, Journal of Structural Geology, 126, 83-99. https://doi.org/10.1016/j.jsg.2019.05.003. Pace, B., L. Peruzza, G. Lavecchia, and P. Boncio (2006): Layered seismogenic source model and probabilistic seismic-hazard analyses in central Italy. Bulletin of the Seismological Society of America, 96(1), pp.107-132. Roberts, G. P., and A. M. Michetti (2004): Spatial and temporal variations in growth rates along active normal fault systems: an example from The Lazio–Abruzzo Apennines, central Italy. Journal of Structural Geology, 26(2), 339-376. http://dx.doi.org/10.1016/S0191-8141 (03)00103-2. THE SHALLOW STRUCTURE OF A SURFACE FAULT OF THE 30 OCTOBER 2016 MW 6.5 CENTRAL ITALY EARTHQUAKE FROM MULTIDISCIPLINARY GEOPHYSICAL APPROACH S. Maraio 1 , F. Villani 2 , L. Serri 1 , P.P.G. Bruno 3 , L. Improta 2 1 Centro di Geotecnologie, Università di Siena, Italy 2 Istituto Nazionale di Geofisica e Vulcanologia, Italy 3 Dipartimento di Scienze della Terra, dell’Ambiente e delle Risorse, Università di Napoli Federico II Introduction. The Pian Grande di Castelluccio is ~20 km 2 wide intermontane basin developed in the hangingwall of the Mt. Vettore normal fault-system (Fig. 1; Calamita and Pizzi, 1992, 1994; Calamita et al. 1992). The almost flat-bottomed plain (1300 m a.sl . average elevation) is surrounded by high and steep slopes on the western side and particularly on the eastern border, where Mt. Vettore (2476 m) represent the culmination of a > 1100 m high cumulative fault scarp. The substratum is made of Jurassic to Paleogene shallow-to-deep marly-calcareous deposits, and the plain is filled with sequences of lacustrine, alluvial fan and fluvio-glacial deposits (Coltorti and Farabollini, 1995; Pierantoni et al. 2013). The 30 October 2016 Mw 6.5 earthquake caused surface ruptures along this mountainside and within the plain (Villani et al. , 2018): here, coseismic breaks closely follow the trend of a subtle fault scarp affecting Late Pleistocene to Holocene alluvial fan deposits, and which we label Valle delle Fonti fault (VF fault). On 30 October 2016, the average coseismic throw along this fault was about 0.05 m, and the overall rupture length is about 1.8 km. The paleoseismic history of the VF fault was first studied by Galadini and Galli (2003) and later revised by Galli et al. , (2019) and Cinti et al. , (2019). Villani and Sapia (2017) suggest syn-depositional fault activity producing