Three-dimensional seismic images of the Larderello-Travale geothermal Area-Italy from microseismic travel time data

Advanced seismological investigations such as a precise events location, a four-dimensional monitoring of the microseismic activity and an accurate study of moment tensors can be inherently supportive for the management of a geothermal field. However, since any of the above mentioned investigations requires accurate velocity models, a detailed knowledge of the three-dimensional P and S wave velocity structures can reveal crucial data both for the management of the field and for the further development of the geothermal source. Therefore, this study has been addressed to image the P- and S- velocity structures of the Larderello-Travale field by a three-dimensional microearthquakes tomographic inversion methodology. Due to the non-uniqueness of seismic velocities alone as indicators of variable rock properties, we also imaged the Vp/Vs and Vp*Vs parameters of the Larderello-Travale field to emphasize variations in the subsurface of the physical rocks properties as fluid content and porosity, respectively. A comparison of these parameters with theoretical values deriving from effective porous medium modeling has been performed in order to interpret the results in terms of rock physics signatures.