Examples of worldwide geothermal productioninduced seismicity: considerations and suggestions for seismic monitoring

In Italy, the actual geothermal concessions for the use of the geothermal resources expire in 2024. By the forthcoming assignment of the mining rights participate - beyond ENEL-Greenpower - also players of the free market, who intend to apply new technologies, accessing, however, one and the same geothermal reservoirs of Larderello-Travale and Mt. Amiata. The use of different methodologies (partial or complete reinjection), in adjacent areas, requires an advanced monitoring system, capable to locate microseismicity in real-time, calculating the relevant seismic parameters and communicating the results in quasi-real-time to the involved concessions, the competent authorities and the population. Following the initiative of the "Regione Toscana", the role as responsible monitoring agency (SPM) has been assigned to INGV, with the purpose to guarantee a homogeneous and centralized monitoring of all concessions operating in the Tuscan geothermal areas. Concerning power plants under national jurisdiction, the ministerial guidelines propose an experimental alert- and reaction-scheme, for water reinjection, exclusively. In this perspective, it is important to stress the actual lack of specific guidelines for geothermal exploitation on regional level. The aim of the present work is to summarize the experiences collected during the management of geothermal systems in other countries and to promote the drafting of a document that defines an appropriate communication scheme for application of the monitoring tasks by the SPM. Such a scheme may represent the basis for developing a reaction scheme and could be useful for the implementation of future regional monitoring guidelines for geothermal activities.