GNGTS 2016 - Atti del 35° Convegno Nazionale

144 GNGTS 2016 S essione 1.1 A MULTI-METHOD APROACH TO IDENTIFY OUTCROPPING AND BURIED ACTIVE FAULTS: CASE STUDIES P. Luiso 1 , V. Paoletti 1 , G. Gaudiosi 2 , R. Nappi 2 , F. Cella 3 , M. Fedi 1 1 Dipartimento di Scienze della Terra, dell’Ambiente e delle Risorse, Università degli Studi «Federico II», Napoli, Italy 2 Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italy 3 Dipartimento di Scienze della Terra, Università degli Studi della Calabria, Arcavacata di Rende (CS), Italy Introduction. This study consists in a multiparametric data analysis carried out by the integration of tectonic, seismic and gravimetric datasets in GIS (Geographic Information System) environment, with the aim of identifying seismogenic structures and constrain their geometry. We have chosen three areas to test this innovative approach: • ������� ���� �������� ������� ��� �� ��� ���� ������ ����� ���� � ���������� ����� �� Abruzzo area (central Italy), one of the most active zones from a geodynamic point of view of the Italian Apennines. It is characterized by the occurrence of intense and widely spread seismic activity. The NE–SW extensional regime affecting this portion of the chain generated subparallel NW–SE trending normal fault systems and large intermountain extensional basins such as the L’Aquila, Sulmona and Fucino ones (Lavecchia et al. , 2012). The L’Aquila area was struck by the Mw 6.1 earthquake (on April 6, 2009) and by its sequence; • ��� �������� �� ������ ���� �������� �������� ������� ����� ��������� ������� �������� San Giuliano di Puglia area (Molise, southern Italy), whose 2002–2003 seismic sequence (two main events with Ml 5.4 and 5.3, recorded on October 31 – November 1, 2002) was close to the frontal thrust of the Apennine units. Nevertheless, the hypocentral depths indicate that the earthquakes were located below the underlying Apulian shelf-carbonate sequence (Valensise et al. , 2004; Galli et al. , 2004; Chiarabba et al. , 2005); • ������� ���� � �� �������� ���������� ����� �� ��� �������� ��������� ������ ��������� Massico Mt., a NE trending carbonatic horst in the northern Campanian region (southern Italy) bordered by two anti-Appenninic normal faults that separate it from the two depressions of Garigliano and Volturno rivers (Billi et al. , 1997). The fault in the northern sector of the Massico Mt. has a subvertical geometry and the fault in the southern sector of the mount is a normal fault dipping 70° SE. Data analysis. The “ fault dataset ” was built by merging all outcropping and buried faults extracted from geological and geophysical papers (Cinque et al. , 2000; Billi and Salvini, 2000; Galadini and Galli, 2000, 2003; Milia et al. , 2003; Boncio et al. , 2004; Valensise et al. , 2004; Vezzani et al. , 2010; Falcucci et al. , 2011; Moro et al. , 2013) and from the available structural and geological maps: ITHACA catalogue; DISS database, several geological sheets 1:50,000 from ISPRA-CARG project; the Neotectonic Map of Italy 1:500,000 (Ambrosetti et al ., 1987); the Structural Map of Italy 1:500,000 (Bigi et al. ,1992); Geological Map 1:100,000; Geological Map of the southern Apennines 1:250,000 (Bonardi et al. , 1988), the Geological- Structural map of the central-southern Apennines (Vezzani et al. , 2010). The faults extracted have been digitalized and plotted on the shaded relief maps of the corresponding three areas. We created an attribute table containing for each fault: ID number, age, geographical coordinates, slip rate, bibliography. The “ earthquake dataset ” consists of seismic data extracted from the available historical and instrumental catalogues: CPTI15 Catalogue of Parametric Italian Earthquakes (Rovida et al. , 2015) containing the earthquakes locations from year 1000 to 2014 A.D.; ISIDE (Italian Seismological Instrumental and Parametric Database) database containing all the Italian earthquakes since 1985 recorded by the Italian permanent seismic network. Seismic data have been merged in a single data set and an attribute table that includes the date of the seismic event, geographic coordinates and the focal parameters for each earthquake was created. As regards the “ gravimetric dataset ”, we performed a Multiscale Derivative Analysis (MDA, Fedi et al. , 2005) of the gravity field, which makes use of the good resolution properties of the Enhanced Horizontal Derivative signal (EHD, Fedi and Florio, 2001), a high-resolution edge estimator. We used the MDA to interpret the Bouguer anomalies of the three studied