Induced and Natural Seismic Swarms: a universal driving process? – INSeiS

Fluid pressure perturbations induce earthquakes at different scales, both in natural seismic swarms or during anthropogenic activities in geological reservoirs. In both contexts, seismicity may either stop on its own or be the precursor to larger, damaging earthquakes. For seismic risk mitigation and for safer energy exploitation, it is of crucial importance to anticipate the evolution of swarms. With this aim, understanding the processes at depth that trigger and drive seismicity is key, but the complex interaction between fluid pressure, aseismic deformation and earthquakes is still an open question. Motivated by recent models that conciliate fluid pressure and aseismic processes, the INSeis project aims to shed new light on the driving mechanisms of both natural and artificially induced swarms. The final goal is to propose common interpreting models in order to better anticipate swarms evolution.

This project focuses on a refined analysis of seismological data from three well-instrumented sites in Europe, with different contexts and scales: (1) geothermal activities in Alsace (France), (2) natural swarms in the Corinth Gulf (Greece), and (3) in-situ experiments of induced seismicity at a decameter scale (France, Switzerland). New physical models and interpretations will be tested and validated with the support of up-to-date hydro-mechanical simulations, that compute seismicity together with the full pressure and deformation history. Finally, we will take advantage of the differences in scale, geological settings and conditions to highlight similarities in the physical processes, in order to bridge the gap in interpretations among geological objects. Finally, through statistical means, we will test and evaluate which metrics and which strategies allow for the best anticipation of the swarm behaviors.