Pourquoi pas? GEOVIDE (GA01)

Cruise summary report

Cruise Info. 
Ship name (ship code)Pourquoi pas? (35PK)
Cruise identifierGEOVIDE (GA01)
Cruise period2014-05-15 — 2014-06-30
Port of departureLisbon, Portugal
Port of returnSt. John's, Canada
ObjectivesGEOVIDE, An international GEOTRACES study along the OVIDE section in the North Atlantic and in the Labrador Sea

Understanding the ocean chemistry of trace elements and their isotopes (TEIs) will improve our ability to probe the past and present ocean system. Some TEIs are toxic for the environment, while others serve as essential micronutrients. Their interactions with the marine food web strongly depend on their chemical (organic and redox) and physical (particulate/colloidal/dissolved) speciation, with continuous exchange between these phases. Some TEIs are also diagnostic and allow the quantification of specific oceanic mechanisms that can hardly or not be investigated by direct measurements. TEIs provide constraints and flux estimates that can also be exploited to reconstruct past environmental conditions, and to estimate the possible amplitude of future climate changes. Despite all these major implications, the distributions, sources, sinks and internal cycling of TEIs are still largely unknown because of the lack of appropriate sampling and (up to very recently) the insufficient sensitivity of the analytical tools. Recent advances now provide the marine biogeochemist community with a great opportunity to make substantial contributions to the understanding of the oceanic system. It is in this general context that the international GEOTRACES programme intends to characterize the TEI distributions throughout a Global Survey, consisting of ocean sections, and regional process studies, using a multi-proxy approach. The proposed GEOVIDE section will be the French contribution to this Global Survey in the North Atlantic Ocean.


1. Better know and quantify the MOC and the carbon cycle in a decadal variability context, adding new key tracers.
2. Map the TEI distribution with their physical and chemical speciation along a full-depth high resolution ocean section.
3. Investigate the link between the TEIs, and the production, export and remineralisation of particulate organic matter.
4. Identify the TEI sources and sinks and quantify their fluxes at the ocean boundaries.
5. Better understand and quantify the paleoproxies 231Pa/230Th, Nd, and 30Si.
Chief scientistGéraldine Sarthou (Laboratory of Marine Environmental Science (UMR CNRS 6539))
ProjectGEOTRACES -Trace elements and their isotopes in the water column
Cruise reportPourquoi pas? GEOVIDE (GA01) cruise report pourquoipas_geovide.pdf (3.65 MB) 
Ocean/sea areas 
GeneralNorth Atlantic Ocean
Labrador Sea (Davis Strait)
SpecificNorth Atlantic along the OVIDE section and in the Labrador Sea
Track chartsPourquoi pas? GEOVIDE (GA01) cruise track — pourquoipas_geovidetrk.pdf (0.24 MB) 
Data held at BODC 
Discrete samples 
18  Atmospheric air sampling pumpMetal concentrations in the atmosphere
Inorganic phosphorus species concentrations in the atmosphere
Concentration of nitrogen species in the atmosphere
Concentration of inorganic halogens in the atmosphere
Sulphur species concentrations in the atmosphere
172  CTD frame plus rosette samplerRadioactivity in water bodies
Vertical spatial coordinates
Salinity of the water column
Temperature of the water column
Dissolved oxygen parameters in the water column
10  Rain water collectorPrecipitation chemistry
54  Dissolved metal concentrations in the water column
Radioactivity in water bodies
Total metal concentrations in water bodies
Vertical spatial coordinates
Salinity of the water column
Temperature of the water column
Dissolved oxygen parameters in the water column