History of Epos-France

Résif-Epos, 2008-2023

At national level, the Résif-France consortium was created in 2011. However, the research infrastructure had been included in the roadmap of research infrastructures published by the French Ministry of Higher Education and Research since 2008, with a disciplinary outline consistent with the initial orientations of EPOS, i.e. seismology and geodesy, but including gravimetry as well. Between 2008 and 2023, Résif-Epos has deployed a unique range of instruments throughout France, now fully integrated into Epos-France.

In seismology, Résif-Epos has developed a dense, permanent network of almost 200 high-bandwidth sensors across mainland France. The permanent accelerometer network is complemented by sensors dedicated to the study of strong movements in the most seismic zones of mainland France and the French overseas territories (Antilles, Réunion, Mayotte). These networks enable researchers to better understand and image the Earth’s interior, from its crust to its core. The basic tools for real-time monitoring of seismic activity, they also help to estimate seismic hazard, i.e. the probability of a vibration exceeding a certain threshold in a given place and over a given period of time.

Résif-Epos has also built up a permanent network of geodetic stations. Capable of measuring ground displacement speeds of the order of a few tenths of a millimeter per year, they enable us to monitor deformations of the earth’s crust and the processes behind relief and seismicity, particularly at fault level. A fleet of gravimeters measures minute variations in the gravity field, enabling us to study the distribution and dynamics of masses inside the Earth.

In addition to these permanent networks, Résif-Epos has coordinated a number of mobile instrument fleets, enabling us to temporarily increase the density of measurements in France or in areas of high scientific interest in Europe or worldwide. Résif-Epos also contributed to prevention and operations: hazard and earthquake risk assessment, rapid damage assessment and crisis management, building standards, the link between building damage and seismicity, seismicity induced by human activity, and more.

From Résif-Epos to Epos-France

Following the request made to CNRS and BRGM in March 2022 by the French Ministry of Higher Education and Research, the evolution of Résif-Epos towards Epos-France was initiated. Scientifically, this change was consistent with the evolution of research into processes inside the Earth, relying de facto on increasingly interdisciplinary research teams and a continuum of observation and measurement techniques.

Instead of piling up administrative structures, it was proposed to transform the Résif-Epos Consortium into the Epos-France Consortium. The legal structure was first put in place on October 6, 2023, with the signing of the first consortium agreement. The new IR, officially launched on Novembre 8, 2023, builds on the  community involved in Résif and its structuring into specific and transversal Actions, and continues to pursue its missions. It is also based on an informal structure that had been coordinating French participation in EPOS since 2010, and which has been integrated into Epos-France as the Transverse action: Coordination of the French contribution to EPOS.

Once the legal basis was in place, the scientific and technical evolution began. With the exception of the themes present in Résif, which were automatically integrated into Epos-France, the majority of French solid Earth research is destined to find a place within the new IR thanks to the integration process put in place.