The Marine Geosciences (Géosciences Marines — GM) unit carries out research to enhance knowledge on the ocean domain (geological structures and processes in the deep sea, exploration of the continental shelf and the deep seabed), and participates in the technological developments required to conduct this research.
The GM unit, located in Brest and in Noumea, is composed of four research laboratories and services:
- Geological Risks and Sediment Dynamics laboratory (Aléas géologiques et Dynamique sédimentaire — LAD)
- Geochemical Cycles and Resources laboratory (Cycles Géochimiques et ressources — LCG)
- Geodynamics and Sediment Recording laboratory (Géodynamique et enregistrement sédimentaire — LGS)
- Mapping, Data Processing and Instrumentation service (Cartographie, Traitement de données et Instrumentation — SCTDI)
The missions of the unit are to study the geological evolution of the seafloor, assess and develop the oceans’ resources and foster their sustainable exploitation. The unit focuses in particular on the following research topics:
- global understanding of ocean basins and continental shelves,
- active or passive shelves (geodynamics, formation of continents, etc.),
- geological risks (tsunamis, earthquakes, submarine avalanches),
- sediment transfers with regards to climate, sea level and tectonic variations, particularly in submarine canyons,
- hydrothermal systems (mineralisation, fluids, biodiversity, etc.),
- cold seeps and gas hydrates,
- mineral resources.
The unit also guides public marine policies through assessments and opinions (aggregates), and exploration permit applications for France. It conducts studies for the extension of the French maritime domain.
Its fields of expertise are geology, geodynamics, geophysics, geochemistry, metallogeny, sedimentology, instrumentation and mapping. To conduct research, the unit relies on marine equipment such as multibeam sounders (bathymetry and reflectivity), coring, geotechnical measurement tools, seismic acquisition tools (several scales), tools for in situ geochemical measurements and underwater vehicles (ROV, Nautile, video cameras, etc.). These instruments and apparatuses are supplemented with laboratory equipment.