GNGTS 2018 - 37° Convegno Nazionale

224 GNGTS 2018 S essione 1.2 anymore; accordingly, we hypothesize that it is probably generated by atmospheric phase artefacts correlated with the topography of the area. Therefore, we consider that the ground surface affected by deformation phenomena are relevant to the central subsided area and the two adjacent uplifted lobes. Starting from these evidence, we compute the rock volumes affected by uplift and subsidence phenomena, highlighting that those involved by the retrieved subsidence are characterized by significantly higher deformation values than those affected by uplift (about 14 times). In order to provide a possible interpretation of this volumetric asymmetry we extend our analysis by applying a 2D numerical modelling approach based on the finite element method, implemented in a structural-mechanic framework and exploiting the available geological and seismological data and comparing the results with the ground deformation measurements retrieved from the multi-orbit ALOS-2 DInSAR analysis. In this case, we consider two different scenarios, the first one based on a single SW-dipping fault, the latter on a main SW-dipping fault and an antithetic zone. In this context, the model characterized by the occurrence of an antithetic zone presents the retrieved best fit coseismic surface deformation pattern. The results of our 2D modelling highlight that the presence of an antithetic zone is necessary to reach the best fit between measured and simulated coseismic surface deformations. This scenario allows us to justify the occurrence of subsidence and uplift phenomena caused by the M w 6.5 Norcia earthquake as the result of combination of pure double couple mechanism along the main fault and gravitational accommodation of the involved rock volumes. References Barchi M.R.; Alvarez W. and Shimabukuro D.H; 2012: The Umbria-Marche Apennines as a Double Orogen: observations and hypotheses. It. J. Geosci., 131, 258-271, DOI 10.3301/IJG.2012.17. Chiaraluce L.; Di Stefano R.; Tinti E.; Scognamiglio L.; Michele M.; Casarotti E.; Cattaneo M.; De Gori P.; Chiarabba C.; Monachesi G.; Lombardi A.; Valoroso L.; Latorre D. and Marzorati S.; 2017: The 2016 Central Italy seismic sequence: A first look at the mainshocks, aftershocks and source models. Seism. Res. Lett., 88, DOI 10.1785/0220160221. Galadini F. and Galli P.; 2003: Paleoseismology of silent faults in the Central Apennines (Italy): the Mt. Vettore and Laga Mts. Faults. Ann. Geophys., 46, 815-836. PRESENT DAY GEOKINEMATICS OF CENTRAL EUROPE A. Caporali 1 , J. Zurutuza 1 , M. Bertocco 1 , N. Cenni 1 , M. Ischenko 2 , O. Khoda 2 , M. Becker 3 , G. Stangl 4 , E. Brockmann 5 , A. Kenyeres 6 , M. Lidberg 7 1 Università di Padova, Dipartimento di Geoscienze, Padova, Italy 2 Main Astronomical Observatory, National Academy of Sciences, Kiev, Ukraine 3 TU Darmstadt, Darmstadt, Germany 4 BEV Bundesamt fuer Eich- u. Vermessungswesen, Wien, Austria 5 Swisstopo - Swiss Federal Office of Topography, Bern, Switzerland 6 Satellite Geodetic Observatory, Budapest, Hungary 7 Lantmateriet, Gaevle, Sweden TheCentral EuropeanGeodynamicResearchNetworkCEGRN. TheCEGRNconsortium has its origin in the framework of the project called CERGOP (Central European Research on Geodynamics Project) that started in 1993-1994 (Fejes and Kenyeres, 1994). The CERGOP consisted originally of 11 countries of Central Europe: Austria, Croatia, the Czech Republic, Germany, Hungary, Italy, Romania, Poland, Slovakia, Slovenia, and Ukraine. In 1998, Albania, Bosnia and Herzegovina, and Bulgaria (associated member since 1996) joined the CERGOP (second phase). All these countries agreed to organize the CEGRN consortium to operate,