1. Home
  2. Presentation
  3. Scientific and societal issues

Scientific and Societal Issues

The scientific and societal challenges posed by natural hazards and the exploitation of geo-resources require high-performance equipment for observing the structure and dynamics of the Earth. The Résif-Epos instrument has been implemented for this purpose, and relies on terrestrial, marine and space resources.

By combining very high spatial density of measurements and very high temporal resolution, Résif-Epos allows us to provide reliable and freely accessible data on the internal movements of the Earth (associated with earthquakes, tectonics, volcanoes…), covering time scales ranging from a fraction of a second to a decade.

A response to real needs in metropolitan and overseas France

Résif is an instrument installed mainly on the French metropolitan territory, where the seismicity, qualified as weak to moderate, is characterized by a great diversity of tectonic contexts. Although often precisely mapped on the surface, the depth extension and current deformation of tectonic structures remain poorly known. Similarly, historical seismicity in France is difficult to understand because it mentions rare destructive seismic events (e.g., the Lambesc earthquake in 1909 or the Teil earthquake in 2019), interspersed with long periods of relative calm. In the absence of dense observations, this context has made it difficult to understand the dynamics of tectonic structures. Beyond the metropolitan territory, Résif-Epos distributes seismological and geodetic data from overseas departments and territories, where natural hazards (earthquakes, volcanoes, landslides, tsunamis) are a major issue. Finally, Résif-Epos distributes permanent and temporary data from networks installed abroad, thus contributing to monitoring and fundamental research on a global scale.

Three complementary components and an intense scientific collaboration

The seismological component of Résif-Epos, with its increasingly homogeneous coverage and the performance of its sensors, aims to better characterize seismicity in a wide range of magnitudes, and to better understand the propagation of seismic waves and their effects on movements on the surface and in buildings. In addition, it leads to a better understanding of tectonic and volcanic structures and potentially active faults. The geodetic component allows us to identify and model with increased accuracy the geodynamic mechanisms responsible for seismicity and eruptions. Gravity measurements, on the other hand, shed light on the spatial and temporal variations of the gravity field related to the structure and dynamics of the Earth.  For each of these three components (seismology, geodesy, gravimetry), Résif-Epos also supports the deployment of temporary experiments on targeted objectives (thus offering a significant densification of the spatial sampling) and the collection of the associated data. Finally, Résif-Epos is the focus of an intense collaboration between scientists of these three components through, in particular, a transverse action around the seismicity of France.

Since its creation, Résif-Epos has been closely integrated into the European geophysical observation systems. The study of many natural phenomena (e.g. earthquakes or large-scale tectonic deformation) requires crossing borders, and Résif-Epos is part of a common effort to facilitate and encourage studies on a continental scale.

A contribution to society

Human activities can also have an impact on geological hazards. For example, triggering of earthquakes by subsurface resource development activities has been documented in many parts of the world. The responsible and sustainable management of underground resources is an unavoidable issue for the decades to come.  The technical and scientific progress made possible by Résif-Epos in the fields of seismology, geodesy and gravimetry, as well as the transfer of know-how to industrial partners, will contribute to a better exploitation and management of underground resources in France and abroad. The targeted fields are energy (geothermal energy), products (ores), storage (reservoirs), water resource management, as well as the evaluation of hazards and associated risks.

The action of Résif-Epos towards society is also concretized in the educational field (secondary education, high schools, universities), through educational documents allowing a better understanding of natural hazards and their societal impacts.

The major role of Résif-Epos in all its fields of expertise is recognized through the support of the Ministry of Higher Education, Research and Innovation, the Ministry of Ecological Transition and that of the Ancre and AllEnvi alliances, as well as through the involvement of all the organizations and universities members of the Résif-Epos consortium.