GNGTS 2018 - 37° Convegno Nazionale

42 GNGTS 2018 S essione 1.1 embedding earthquake causative fault systems. Indeed, the contribution of pore fluid pressure changes to earthquake triggering at different rupture scales is recognized worldwide (Hardebeck and Hauksson, 1999) and has been already invoked for several Italian Apennine cases (Improta et al. , 2014). Beside velocity, attenuation tomography may provide useful and complementary insights into the physical properties of fluids, which permeate host rocks (Hauksson and Shearer, 2006). Detection, mapping, and tracking of fluid migration can notably be achieved using 4D seismic tomography and is used especially for purposes such as oil exploration and reservoir monitoring, understanding tectonic environments and volcano monitoring for short- to middle- term eruption forecasting. However, these observables are not able to single out the rock micro-parameters, as porosity, saturation or type of permeating fluid (Dupuy et al. , 2016), which are necessary to define a reliable picture of the host rock physical properties. If we are interested in a quantitative interpretation of seismic attributes in terms of micro-parameters values, we need to introduce a poro-elastic rock modelling, taking into account as far as possible the complexity of the host medium physical condition. Finally, the joint use of a double-difference (DD) methodology and an accurate differential time data set allows to carry out a high-resolution, earthquake location analysis, which helps to characterize the active fault geometries. Fig. 1 - (a) Geological map of the southern Apennines, showing location of seismic stations and main historical and instrumental earthquakes. (b) Cross-section (after Ascione et al. , 2013). (c) Vp model and earthquake locations projected onto the cross-section located in Fig. 1a. Grey-dashed curves delimit the well-resolved region of the model according to the checkerboard resolution test. (d) Vp/Vs ratio for the same depth section as in Fig. 1a. Modified after Amoroso et al. (2014).