Hydromechanics and induced seismicity in geothermics

**Description of the project

"The announced end to the use of carbon-based energies and the phasing out of nuclear power require an energy transition towards the massive use of non-carbon-based renewable energies; taking over implies considerable investment, particularly in research. Geothermal energy can be a source of energy, but its use comes up against the problem of seismicity induced by the pressurisation of fluids in volumes where the tectonic constraint is not negligible, which could lead to its prohibition. This project falls within this framework. It proposes to study the seismic data recorded on the Epagny-Annecy site (where an earthquake M 5.3 took place in 1996). On this site, our investigations tend to show that a pressurised aquifer hydraulically charges the (active) Vuache fault and induces seismicity. The first step will be to fully explore the existing database (3 RAP stations on site) to detect (1) local microseisms and investigate whether there are seasonal variations, which could be related to the hydraulic recharge variations of the aquifer, (2) velocity variations in different frequency bands related to piezometric level variations. Continuous monitoring of the flow and temperature of the Bromine springs will also be carried out. The final objective is to model the seismic response to this hydraulic loading."