Structure du projet
The project requires multidisciplinarity (geophysics, fluid chemistry, physical oceanography, ecology, microbiology and engineering) and a good integration of different types of data, with consideration for their quality and for their spatial and temporal resolution. Reaching this level of integration will be our main goal in project management. It will condition our ability to produce useful models of the dynamics and functioning of the hydrothermal ecosystem. It is also needed to address our other goal of designing a new prototype for multidisciplinary environmental monitoring in the deep seafloor, with data made available through the EMSO data center.
Working on this prototype, from its technological characteristics to data validation and dissemination procedures cannot be done fully within individual workpackages: it must be coordinated at the project scale. Our experience is that the best approach to facilitate integration so that it can then progress through regular interactions between the workpackages, is to organize frequent (yearly) and relatively long (3 days) workshops. We propose to have a specific “Workshops, data dissemination and valorisation” workpackage to organize these workshops and make sure that the project reaches its goals in terms of data dissemination and valorisation. The 6 proposed workpackages are numbered irrespective of hierarchy.
Description of the workpackages
WP 1 : Focused end-member fluids
The first objective for WP1 is to characterize the focused hydrothermal fluids that represent the hot end-member for the smaller-scale circulations that lead to the formation of diffuse vents and gradient zones at Tour Eiffel. The temperature and chemistry of these fluids, as well as informations on their temporal variability will constitute deliverables from WP1 to WP2.
The second objective of WP1 is to work on these data to better understand the magma chamber to vent hydrothermal processes depicted in Figure 2. Deliverables for this second objective will be seismological constraints and numerical models of the geometry of hydrothermal downflow, and constraints on fluid-rock reactions and on the entrainment of brines produced by phase separation in the fluids at depth near the magma chamber, including of course their temporal variability.
The third objective of WP1 is to contribute to the implementation of the proposed prototype for multidisciplinary environmental monitoring in the deep seafloor. Deliverables will be the development of adapted validation and dissemination procedures (including the format of near real time data transmission and alerts) for the data collected by two new instruments (inset 1) at the Lucky Strike observatory.
WP 2 : Small scale subseafloor circulations
The first objective for WP2 is study the smaller scale hydrological circulations and processes that transform focused end-member hydrothermal fluids into diffuse effluents and gradient zones. The temperature and chemistry of diffuse fluids at the hydrothermal habitats of the Tour Eiffel vent site, as well as information on their temporal variability will constitute deliverables from WP2 to WP4.
The second objective of WP2 is to contribute to the implementation of the proposed prototype for multidisciplinary environmental monitoring in the deep seafloor. Deliverables will be the operation of several new or upgraded instruments (inset 2) at the Lucky Strike observatory, the connection of some of these to the observatory transmission system, and the development of data validation and dissemination procedures for monitoring data that pertain to the 100m to 1 cm scales of hydrothermal circulation.
WP 3 : Water column dynamic
The main objective of WP3 is to bring a consistent 3D view of the hydrodynamics in the vicinity of the Lucky Strike vent field using a state-of-the-art realistic high resolution (HR) ocean model. From this consistent picture we will determine the relative contribution of the various forcings on the currents (tidal, geothermal, upper layer mesoscale turbulence), disentangle the deterministic steady laminar part from the chaotic intermittent turbulent part. This study should allow us to better understand the complexity of the flow near the vents and thus provide new ideas to improve the observation of currents in the area. This has never been done for a deep sea hydrothermal vent and we therefore expect to make a significant contribution, although the proposed physical oceanography modelling will not be able to descent to the minute scales (< 1m) of hydrothermal habitats.
WP 4 : Faunal and microbial response
The first objective for WP4 is to study the faunal and microbial response to hydrothermal forcing. We will use the multivariate statistics of abiotic environmental parameters developed in WP2, time series images of faunal assemblages obtained with the TEMPO module, and the analysis of faunal and microbial assemblages collected yearly from a pool of seafloor colonisation substrates, as a basis to elaborate a model of "ecosystem functioning » for deep sea hydrothermal environments.
The second objective of WP4 is to contribute to the implementation of the proposed prototype for multidisciplinary environmental monitoring in the deep seafloor. To this aim, we will use the ecosystem functioning model to identify the most pertinent indicators of faunal and microbial variability and to address questions that pertain to the management, conservation and protection of deep-sea ecosystems.
WP 5 : Engineering
The objective of WP5 is to coordinate the technical implementation of the proposed prototype for multidisciplinary environmental monitoring in the deep seafloor. Deliverables will be:
The first objective of WP5 is to build (in house or through external contractors) a new COSTOF (Communication and Storage Front-end) junction box system and several new instruments (insets 1 and 2) for the Lucky Strike observatory. This includes developing the connection of some of these instruments to the COSTOF system and designing the data management plan in compliance with the standards of EMSO.
The second objective of WP5 is to prepare guidelines for the deployment of these new instruments at the seafloor, including an operational plan with estimates of the required ship and ROV time. This preparation is particularly needed for instruments that are bulky, or have to be connected to long cables deployed on the rough seafloor of Tour Eiffel (Figure 7). We will also design procedures for seafloor testing of the instruments and their underwater connection.
WP 6 : Workshops, data dissemination and valorisation
WP6 has three objectives:
The first objective of WP6 is to facilitate the coordination of the LuckyScales multidisciplinary team and promote the scientific and technical exchanges and discussions that are needed to address our scientific objectives.
The second objective of WP6 is to coordinate the work of each WP participant on data validation procedures in their respective disciplinary fields and to contribute relevant derived products to the EMSO data management system, and to other concerned European projects (MIDAS, FIXO3).
The third objective of WP6 is to promote LuckyScales achievements to the general public, schools, the media, other researchers and deep-sea engineers, and potentially interested industries.