SEISMOLOGICAL STUDY OF LARDERELLO-TRAVALE GEOTHERMAL AREA

The seismic network installed by ENEL (Italian Electric Energy Agency) made it possible to detect a high degree of seismic activity in the Larderello-Travale geothermal area, with events that rarely exceeded a magnitude of 3. The spatial distribution of the hypocenters indicated the presence of seismically active structures which can be correlated with those identified on the basis of the geological and geophysical studies carried out during geothermal exploration. Statistical analysis of the seismic data was aimed at defining how elastic energy is released and at observing variations in parameter 'b' in time and space. The correlation between seismicity and water reinjected in the wells located in the geothermal area suggests that part of the low-magnitude seismic events are induced. However, the analyzed data indicate that an increase in the quantity of injected water does not produce an increase in the maximum magnitude value.