SABASETI

Type Oceanographic cruise
Ship Côtes De La Manche
Ship owner CNRS until 2019 - IFREMER since 2020
Dates 11/02/2023 - 18/02/2023
Chief scientist(s) EHRHOLD Axel ORCID, DAGUINOS Paul

GEO-OCEAN - UMR 6538

Univ. Brest, CNRS, Ifremer, Univ. Bretagne Sud

Place Nicolas Copernic

29280 Plouzané

https://www.geo-ocean.fr/

DOI 10.17600/18002538
Objective

The SABASETI mission (SAnd BAnk and SEdiment Transfer on Iroise continental shelf) aims to provide a foundation of new knowledge on the bedform zones and bedload transport paths at the scale of the Iroise Sea. It is based on a thesis in progress (Paul Daguinos, UMR 6538 GEO-OCEAN) and the results of the BANKABLE cruise (2019). The bottom of the Iroise Sea have the particularity of being structured by several large sandbanks between 70 and 90 m deep, relatively close to each other (between 10 and 20 km). They belong to this type of continental shelf in a dispersive macrotidal context (accomodated shelf) described by Berné (1999), with little or no sediment supply from continental sediments. The question of the dynamics of its banks, of their possible interconnection and of their equilibrium under current hydrodynamic conditions, is dependent on the stock of available sedimentary material, its ability to be set in motion and the controlling factors. Understanding the residual sedimentary dynamics of the bioclastic material that makes up most of the matrix of these sedimentary structures also find strong societal resonance on the characterisation of marine habitats with high economic and ecosystemic value, on the question of marine aggregates, as well as on research into underwater archaeology in these environments with high temporal variability. To restore the long-term circulation of sedimentary transports and compare them to the results of historical hydro-sedimentary simulations, it is planned to cover about 650 km of regional profiles (sidescan sonar and multibeam echosounder), encompassing all the banks, and to extract from the observed sedimentary figures the indications of residual transports paths both in direction and intensity.

 

Published data

Daguinos Paul, Le Roy Pascal, Jouet Gwenael, Menier David, Le Dantec Nicolas, Ehrhold Axel, Prunier Christophe, Dupont Pauline, Franzetti Marcaurelio (2024). Long term evolution of deep banner banks offshore Western Brittany (Iroise Sea, France): indications of a paleo-coast line and of the interaction between hydrodynamics and seafloor morphology. https://doi.org/10.17882/99418


Data managed by SISMER