Missions

As part of the DeepSea'nnovation project, the LSCE is developing a deep benthic profiler which will reach the end of its development phase in autumn 2025. Working with the engineer in charge of technical development, the post-doc will then be required to participate in the development phase of the profiler and its scientific exploitation.

Activités

The candidate will be responsible for finalising the development, in particular the implementation of the first sea trials. In addition, the scientific value will be ensured by a publication related to this new profiler and the dynamics of oxygen in sedimentary environments. The post-doc will also be responsible for developing a simple application that can be used by non-specialists to process the raw data from the profiler in order to automatically produce oxygen profiles at the water-sediment interface. He or she will be responsible for writing 3 deliverables requested by the DeepSea'nnovation project.

Compétences

The OCEANIS team at LSCE is looking for a person (M/F) for a full-time 18-month post-doc at LSCE from June 2025 The candidate must
- hold a PhD,
- an interest in marine and underwater technology,
- knowledge of marine biogeochemistry
- basic programming skills (R, Pyton, Fortran).

Contexte de travail

This 18-month CNRS contract is being funded as part of the DeeSea'nnovation project, which aims to develop new research tools for the scientific community that can be operated by underwater robots (ROVs) in the deep ocean. LSCE, in conjunction with INSU's Technical Division (DT), has proposed the development of a new-generation benthic profiler. This device will make it possible to measure, in situ, with sub-millimetre resolution, the vertical distributions of oxygen at the water-sediment interface using optical sensors with micrometre tips.

The national community of deep-sea biogeochemists is interested in the fate of organic and inorganic carbon deposited on the seafloor, the main site for the deposition and recycling of matter in the deep ocean. Most deep abyssal plains are characterised by oxygen-rich waters, which condition the aerobic metabolism of sediment ecosystems and the biogeochemistry of the deep ocean. In order to understand the biological and chemical mechanisms of these environments, it is essential to know and accurately measure the distribution of oxygen in the sediments, which provides access to benthic aerobic mineralisation.

The LSCE, via the OCEANIS team, has been investigating these issues for over 20 years using an autonomous, deep-sea (6000 m) benthic profiler (Lander Unisense). At the same time, the team has worked with a number of profilers (AWI-Germany, SAMS-Scotland) and has acquired extensive experience of these in-situ measuring devices. While all of them provide extremely satisfactory results, it became clear that a simple, robust profiler was needed that would be able to take advantage of the strengths of each existing device while also offering solutions to the weaknesses (autonomy, fragility, memory capacity, diversity of parameters measured, etc.). The LSCE has therefore proposed the design of a brand new profiler that can be used during deep-sea missions. This profiler will be deployed during ROV dives and will be able to document several study sites thanks to the ROV's flexibility of action, the ability to trigger profiles on demand and the profiler's large memory capacity.

The candidate will work at the LSCE, a joint CEA-CNRS-UVSQ unit, on the CEA Saclay site in the Université Paris-Saclay as part of the OCEANIS team.

Contraintes et risques

Short-term travel within France is to be expected (project meetings and tank and/or sea trials).
The LSCE is located at the CEA Saclay centre, and an administrative enquiry concerning the person recruited will be carried out to ensure access to the premises.
The person recruited will have to comply with all the instructions inherent in experimental laboratories of the CNRS. Similarly, in the event of sea trials, the candidate will have to comply with all the safety instructions on board, in particular wearing the personal protective equipment (PPE) provided by the laboratory.