Resif-Epos in the ecosystem of national, European and international research infrastructures

The consortium agreement signed in October 2011 between 18 major players in geophysical research in France has made Résif-Epos a national facility, included in the roadmap of research infrastructures published by the Ministry of Higher Education, Research and Innovation.This roadmap determines for several years the strategy of nearly a hundred international organizations, research infrastructures (RIs) and projects, grouped by major areas.

Among them, the RIs of the Earth and Environment System contribute to the progress of knowledge on the processes at work within the major compartments of the planet, and between them. They are part of a large-scale action entitled “Knowing, monitoring and forecasting the Earth System”. This action contributes to the implementation of scientifically validated information and/or forecasting services on climatic, environmental and land-based risks, and at the same time to offer related services in the field of energy, resources, risk and security in the broad sense. These products and services are intended for the scientific community as well as for public and socio-economic actors.

The RIs of the Earth and Environment System, often distributed, are very diverse. They are conceived on a European [1] or international scale and are built from systems accredited by research institutions and coordinated by the AllEnvi alliance [2].

The Earth System and Environment domain is divided into sub-domains: Logistical Infrastructures (such as the FOF fleet of ships), Internal Earth (Résif-Epos belongs to it), Atmosphere, Ocean and Coast, Continental Surfaces and finally Biodiversity and Ecosystems, not to mention the virtual Earth observation infrastructures. These infrastructures each work in their own field, but the borders are porous and Résif interacts with others, for example in the framework of common multi-instrument sites.

1] ESFRI roadmap, ENVRIplus cluster Environmental Research Infrastructures providing shared solutions for science and society

2] AllEnvi, the national research alliance for the environment, federates, programs and coordinates French environmental research to meet the major societal challenges of food, water, climate and territories.

Here are some examples of interactions between Résif and other research infrastructures

Résif-Epos and the RI “Critical Zone Observatories: Application and Research” (Ozcar)

Ozcar brings together instrumented sites that rely on long-term observations of water, ice, soils, wetlands and their biodiversity. Two of the observatories affiliated to Ozcar are multi-instrument sites also hosting Resif seismological and geodetic instruments.

This is the case of the Hydrogeochemical Environmental Observatory (OHGE) on the Strengbach watershed in the Vosges mountains (Aubure, Haut-Rhin). Created in 1986, it has a role of study and long-term monitoring of ecosystems and their modifications in connection with natural or anthropic disturbances. The equipment installed on the Strengbach catchment area allows the acquisition of meteorological, hydrological and geochemical data on the scale of the whole catchment area. The site also hosts the Sipazoc project, whose objective is to evaluate the ability of different passive seismic approaches to characterize the properties of the critical zone, the evolution of its water resources and the dynamics of surface transport on a catchment scale, as well as gravimetric, geodetic and magneto-telluric observations. A GNSS Renag station (code AUBU) is for example installed there.

The second Ozcar site is the Larzac Observatory. This multi-instrumented site of Durson (belonging to the national network of hydrogeological sites H+) is located on the Larzac plateau (commune of Nant, Aveyron). It ensures the hydro-geophysical monitoring of a karstic hydrosystem by repeated or continuous geodetic and hydrological measurements. Thus, the dynamic storage of water within such aquifers escapes measurement and modeling by classical hydrological methods. By measuring the impact of water on the deformation and gravity field, it is possible to obtain essential information on the hydrological functioning of karst. In addition to the gravity meters integrated in Résif, this site also hosts a seismological station (Code LAJAS) and a GNSS station (Code HOLA) Résif.

Résif-Epos and the coastal research infrastructure (Ilico)

Created in 2016, the coastal and littoral research infrastructure (Ilico) aims to observe and understand coastal and marine environments and ecosystems in their entirety. Thus, Ilico brings together a set of observation devices to collect samples and deploy various measurement instruments by federating eight observation services, including Sonel.

The Coastal Water Level Observation System Sonel is a project for in situ observation of sea level at the coast, and for making observations and associated solutions available. Sonel provides metrological quality sea level observation data from tide gauges and geodetic techniques (GNSS, levelling…) to study long-term sea level change trends, to calibrate satellite instruments and to understand coastal sea level change processes. Sonel acts as the GNSS data center at tide gauges for the Global Sea Level Observing System (GLOSS) program, which is under the auspices of the Intergovernmental Oceanographic Commission (IOC) of UNESCO.

Other links remain to be developed between Résif-RLBP and Ilico around the monitoring of sea state, wave/coast interaction, etc. … from seismological data of RLBP and especially seismic noise in the microcosmic band.

Resif-Epos and the Emso research infrastructure

The European Multidisciplinary Seafloor and water column Observatory is a pan-European research technology infrastructure for continuous, interactive, high-resolution observation of the oceans via a system of regional facilities placed at key sites in Europe, from the Northeast to the Atlantic, Mediterranean and Black Seas. The observatories are platforms equipped with multiple sensors, placed along the water column and on the sea floor. They continuously measure different biogeochemical and physical parameters, which are relevant to natural hazards, climate change and marine ecosystems.

These measurements consist, for example, in the monitoring of seismicity south of the Azores through the Hydromomar project (2010-2020). A network of five autonomous hydrophones has been deployed around the Lucky Strike site, south of the Azores (Mid-Atlantic Ridge), to listen to the sounds of the sea. Oceanic ridges are places where two tectonic plates move apart from each other. Several processes allow this extension: the movements of faults and the rise of magma. These phenomena generate earthquakes whose magnitude is very often lower than 4 and which are not recorded by terrestrial seismological networks. The Hydromomar project aims to understand to what extent these processes act at the level of ridges and if there is a cycle of occurrence for these phenomena.

Within the framework of the new Résif-Marmor action, links with Emso are being strengthened, for example through the development of seismology at the bottom of the sea and the increase of activities around the optical fiber (in particular the Distributed Acoustic Measurement – DAS).

Résif-Epos and other French research infrastructures related to the Earth System in Data Terra

The Data Terra RI is a direct result of the “Knowing, monitoring and predicting the Earth System” action and works to improve the understanding of geophysical, geodynamic and environmental processes. In particular, it works on the analysis of the numerous and very large data sets that characterize these processes.

Data Terra is divided into clusters, including the Solid Earth cluster named Form@Ter. Its mission is to federate existing centers serving the Solid Earth community such as Résif-Epos.

Résif-Epos contributes to this ecosystem of these research infrastructures, first through its primary missions of data collection and distribution, but also through specific projects. For example, it participates in the creation of a Data Terra data repository, common to all Earth System data and interconnected with its European counterparts.

Résif-Epos and European and international research infrastructures

French research infrastructures are thought and structured on a European and international scale. Thus, Résif is the major contribution of France to Epos (European Plate Observing System) and participates actively in its realization and its evolution.

Epos is a European research infrastructure in the solid Earth domain in charge of data integration in Earth Sciences, from pre-existing services in Europe. Epos aims to create an efficient and comprehensive multidisciplinary research platform making accessible and interoperable data and products from observatories, networks and instruments in Earth Sciences disciplines such as seismology, geodesy, volcanology, tectonics, geomagnetism, paleomagnetism, geology. The aim of Epos is to allow the development of innovative multidisciplinary research for a better understanding of the physical and chemical processes of the solid Earth.

Résif-Epos is also a partner in various international observation networks, such as the worldwide network of broadband seismological stations Geoscope, whose French stations are integrated into the Résif information system. In geodesy, the GNSS stations of the worldwide Regina network also contribute to the Résif databases, as do those of the national RGP network managed by the IGN. In the field of gravimetry, the integration and distribution of Résif-Epos data is done through the International Geodynamics and Earth Tide Service (Igets), whose objective is the measurement, archiving and distribution of long time series of superconducting gravimeters, but also of inclinometers, extensometers, etc.