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Fischer, Gerhard; Karakas, Gökay; Blaas, M; Ratmeyer, Volker; Nowald, Nicolas; Schlitzer, Reiner; Helmke, Peer; Davenport, Robert; Donner, Barbara; Neuer, Susanne; Wefer, Gerold (2009): (Table 2) Comparison of annual mass fluxes measured with shallower and deeper sediment traps off Cape Blanc (CB) [dataset]. PANGAEA,, Supplement to: Fischer, G et al. (2009): Mineral ballast and particle settling rates in the coastal upwelling system off NW Africa and the South Atlantic. International Journal of Earth Sciences, 98(2), 281-298,

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The ocean off NW Africa is the second most important coastal upwelling system with a total annual primary production of 0.33 Gt of carbon per year (Carr in Deep Sea Res II 49:59-80, 2002). Deep ocean organic carbon fluxes measured by sediment traps are also fairly high despite low biogenic opal fluxes. Due to a low supply of dissolved silicate from subsurface waters, the ocean off NW Africa is characterized by predominantly carbonate-secreting primary producers, i.e. coccolithophorids. These algae which are key primary producers since millions of years are found in organic- and chlorophyll-rich zooplankton fecal pellets, which sink rapidly through the water column within a few days. Particle flux studies in the Mauretanian upwelling area (Cape Blanc) confirm the hypothesis of Armstrong et al. (Deep Sea Res II 49:219-236, 2002) who proposed that ballast availability, e.g. of carbonate particles, is essential to predict deep ocean organic carbon fluxes. The role of dust as ballast mineral for organic carbon, however, must be also taken into consideration in the coastal settings off NW Africa. There, high settling rates of larger particles approach 400 m day**-1, which may be due to a particular composition of mineral ballast. An assessment of particle settling rates from opal-production systems in the Southern Ocean of the Atlantic Sector, in contrast, provides lower values, consistent with the assumptions of Francois et al. (Global Biogeochem Cycles 16(4):1087, 2002). Satellite chlorophyll distributions, particle distributions and fluxes in the water column off NW Africa as well as modelling studies suggest a significant lateral flux component and export of particles from coastal shelf waters into the open ocean. These transport processes have implications for paleo-reconstructions from sediment cores retrieved at continental margin settings.
Median Latitude: 21.183233 * Median Longitude: -20.708567 * South-bound Latitude: 21.138000 * West-bound Longitude: -20.766700 * North-bound Latitude: 21.266700 * East-bound Longitude: -20.672000
Date/Time Start: 1990-04-08T00:00:00 * Date/Time End: 2002-01-01T00:00:00
Minimum DEPTH, water: 730 m * Maximum DEPTH, water: 3606 m
CB3_trap * Latitude: 21.138000 * Longitude: -20.672000 * Date/Time Start: 1990-04-08T00:00:00 * Date/Time End: 1991-04-30T00:00:00 * Elevation: -4094.0 m * Campaign: M12/1 * Basis: Meteor (1986) * Method/Device: Trap (TRAP)
CB4_trap * Latitude: 21.145000 * Longitude: -20.687000 * Date/Time Start: 1991-05-03T00:00:00 * Date/Time End: 1991-11-19T00:00:00 * Elevation: -4108.0 m * Campaign: M16/2 * Basis: Meteor (1986) * Method/Device: Trap (TRAP)
CB13_trap (CB13) * Latitude: 21.266700 * Longitude: -20.766700 * Date/Time: 2002-01-01T00:00:00 * Elevation: -4131.0 m * Location: Cape Blanc * Method/Device: Trap (TRAP)
#NameShort NameUnitPrincipal InvestigatorMethod/DeviceComment
1Event labelEvent
2Sample code/labelSample labelFischer, Gerhard
3DEPTH, waterDepth watermGeocode
4Total, flux per yearAnn mass fluxg/m2/aFischer, GerhardCalculated, see reference(s)
5Opal, fluxbSiO2 fluxg/m2/aFischer, GerhardCalculated, see reference(s)
6Carbon, organic, fluxTOC fluxg/m2/aFischer, GerhardCalculated, see reference(s)
7Calcium carbonate, fluxCaCO3 fluxg/m2/aFischer, GerhardCalculated, see reference(s)
8Lithogenic, fluxLitho fluxg/m2/aFischer, GerhardCalculated, see reference(s)
9CommentCommentFischer, GerhardInterpretation
39 data points

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