GNGTS 2019 - Atti del 38° Convegno Nazionale

60 GNGTS 2019 S essione 1.1 changing from N140° E to N30°÷40° E from southeaster to northwestern sector of the shear zone (Fig. 2). We analyzed the historical seismicity of the Fiandaca Pennisi fault during the last 150 years, finding 15 earthquakes occurred in different segments of the fault line, the major ones in: 7th and 8th August 1894, 19th June and 25th October 1984. The coseismic effects related to the 26 December 2018 and August 1894 earthquakes show similarities (Fig. 1). Geodetic data. The day after the seismic event, the GEOdynamic and GEOmatic Lab. group of the University of Catania, started the survey of ground deformation related to the earthquake of December, 26 2018 following the method already shown in De Guidi et al. (2017).We realized 3 geodetic benchmarks along the shear zone, extending the UNICT_NET network (De Guidi et., 2018), The posteismic slip of the Fiandaca Pennisi fault resulted in a mainly horizontal movement of more than 12 cm towards WNW and 10 cm towards ESE directions (Fig. 3) (Fig. 2). Fig. 2 - DEM of the area affected by the fault. F1, F2 and F3 are the location where the structural surveys were carried out. The movements of FNC2 and FNC1 benchmarks ( UNICT-NET) are shown. The INGV GNSS network collected data from 34 permanent stations located all around the volcano, showing intense deformative effects also to relatively low heights. These data clearly demonstrate that the active intrusion is related to a tensile effect of an intruded dike at sea level or few hundreds of meters below (Mattia et al. , submitted). GNSS data, recorded from one year before the eruptive event since after the intense intrusive phase, indicate three distinct phase: i) volcanic inflation, ii) high deformation sequence associated with the intrusion of the dyke, iii) increasing and extension overtime of velocity field along eastern volcano slope. Interferometric data (InSAR) were further used to support previous investigations and to better define geometric and the associated developed deformation zone. The high-resolution interferograms were obtained by Observation of Progressive Scans (TOPS) mode from the Sentinel-1 satellite, which provide high-quality Synthetic Aperture Radar images illuminating the shear zone in a time range straddling the seismic event (Fig. 3). We have investigated the surface earthquake effects by means of SAR interferometry using the European Space Agency (ESA) Sentinel-1 A&B satellites acquisitions (C-band). For the