| Title | Understanding the inner structure of Larderello (Tuscany, 05 Central Italy) by a multi-scale integration of geophysical data |
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| Authors | Chiarabba, Vinciguerra, Procesi, Piccinini, Anselmi, Saccorotti |
| Year | 2013 |
| Conference | European Geothermal Conference |
| Keywords | microseismicity, rock physics, geomechanics, seismic signals and fluids, deep structure. |
| Abstract | Larderello is one of the first geothermal systems investigated by geophysical studies and monitored with seismic networks, managed by ENEL operated since 25 years and providing one of the most complete set of seismological observations in geothermal areas. The analysis of microseismicity revealed a clustering of earthquakes along the so-called k-horizon, a sharp seismic reflector interpreted as a fluid-filled layer, and allowed the computation of velocity tomographic models. Very recently, and still operating, a dense 2D seismic network of broadband instruments has been installed by INGV to collect high quality passive seismic data. Aim of this set up is the reconstruction of i) seismicity patterns in space and time, ii) source parameters of micro-earthquakes, iii) 3D velocity and attenuation structure and iv) fractures and fluids in the sub-surface structure. In this framework, the interpretation of geophysical results and well logs, in terms of nature and structure of crustal rocks requires data on the physical properties of rocks which can be obtained experimentally on single samples. In particular, laboratory simulations can allow us to rebuild the thermo-hydro-mechanical mechanisms that occur in geothermal systems, such as, those related to the interplay of supercritical fluids and rock massesIn addition, a better determination of the effects of the confining pressure, temperature and pore fluid pressure on the physical properties of rocks is required for an improved geophysical interpretation of crustal, viz. lithospheric structures, as well as for the understanding of specific failure modes and the identification of brittle-ductile transitions. |