Axe 4 : grand pfond

Deep sea environments are still largely unexplored although they are home to active geological processes that support diverse ecosystems. Information acquisition in these environments is largely dependent on technological advances for sampling and measurements (positioning, mapping and sea bottom image acquisition, geophysical survey, in situ measurements, geological, geochemical and biological sampling thanks to submersibles and ROVs).

The current state of knowledge suggests a poorly studied field in terms of biodiversity and resources, be it for energetic, mineral or microbiological resources. Understanding such ecosystems implies a geobiological approach to appreciate links and interactions between the geosphere, hydrosphere and biosphere. Finally the comprehension of natural volcanic and seismic risks requires a detailed knowledge on processes function in their spatial and temporal dimension. Some topics also require repeated observations over time as well as long term continuous observations.

The geographical focus of Research Axis 4 is set on continental margins, rift zones, the French continental shelf (including the Exclusive Economical Zone and the “legal” continental shelf up to 350 nautical miles from the coast), and some areas of abyssal plains. Approximately two thirds of the Earth heat are evacuated along oceanic rifts, hence making these areas exceptionally interesting in terms of geological and biological activity. Continental margins, as transition zones between the continents and the oceans, undergo the highest sediment accumulation on earth. They also record past climate variations, active geological processes (seismic activity, avalanches, fluid emission) and accumulate significant energetic resources, of which only a fraction have been exploited so far.

IUEM, Ifremer, SBR and SHOM, linked via the GIS Europôle Mer, are particularly well positioned to develop a research direction on deep sea environments thanks to the various expert teams actively working on these themes in West Brittany in marine geosciences, deep sea biology and microbiology, and developing technological tools suitable for deep sea extreme conditions. As an example for deep sea biology, 80% of the teams that form the Research Group (GDR) ECCHIS are located in West Brittany (Ifremer, UBO, SBR).

Research Axis 4 innovative approach in terms of deep sea geosphere, biosphere and hydrosphere interactions resides in its multidisciplinary and temporal strategy. The geobiological study of deep sea extreme environments brings together a unique mix of disciplines in the GIS Europôle Mer in comparison to other French research centres. The temporal strategy mentioned above constitutes an emerging theme and involves permanent deep sea observatories to gain information on interactions dynamics and active geological processes that cause these dynamics. Both these themes are scientific challenges for the next decade due to the extreme conditions and the access restriction to this environment. Some assets to the teams involved to address these questions are:

  1. multi-disciplinarity of member teams (geology, biology and marine chemistry),
  2. expertise in underwater technology (research institutes and engineering training agencies and universities),
  3. leadership at a national and European level (Ifremer hosts the executive office of the network of excellence for marine observatories ESONET),
  4. valorisation tools available (Pôle de Compétitivité Mer, an economic competitiveness cluster),
  5. significance of project proposals for exploration and exploitation of deep sea energetic, mineral and biological resources (link with the industry),
  6. wide potential for postgraduate training and supervision, as well as the high impact and popularity of deep sea topics on the general public.