Fluids induce earthquakes both in the form of natural swarms and when geological reservoirs are exploited. In both cases, seismicity can either stop on its own or represent the precursors of major earthquakes. For our own safety in the face of seismic risk and for the safe development of new energy sources, it is therefore necessary to anticipate the evolution of seismic swarms, which means monitoring their mechanical forcing. However, the complex interactions between fluids, slow and asismic deformations and earthquakes are complex and still poorly understood. The INSeis project is motivated by new models that reconcile these phenomena. Its aim is therefore to improve our understanding of the processes that generate seismic swarms in different contexts and on different scales, in order to improve the forecasting of swarm behaviour.
This project will seek to identify markers of hydro-mechanical forcing by reinterpreting seismological data from 3 well-instrumented sites, in very different contexts: 1) geothermal exploitation in Alsace (France), 2) natural swarms in the Gulf of Corinth (Greece) and 3) in-situ experiments of induced seismicity on a decametric scale (France, Switzerland). The observations and interpretations will then be reproduced and validated by hydromechanical modelling, which calculates the complete response of faults to a fluid disturbance. Finally, we will use the different contexts and scales of natural and synthetic seismological catalogues to extrapolate the interpretations using statistical approaches and estimate the universality of the processes. The results will be used to identify better strategies for anticipating the evolution of seismic swarms.
PI : Louis DE BARROS - debarros@geoazur.unice.fr
ANR 2022
