Chemistry of pore water from Arctic sediments

• Main Authors: Hulth, Stefan, Hall, Per, Blackburn, T H, Landén, A
• Format: Dataset
• Language: English
• Published: PANGAEA 1996
• Subjects: ARK-VIII/2; AWI; AWI_Paleo; Barents Sea; Giant box corer; GKG; MUC; MULT; MultiCorer; Multiple investigations; ORFOIS; Origin and Fate of Biogenic Particle Fluxes in the Ocean; Paleoenvironmental Reconstructions from Marine Sediments @ AWI; Polarstern; PS19/040; PS19/045; PS19/050; PS19/055; PS19/078; PS19/082; PS19/084; PS19/086; PS19/098; PS19/100; PS19/101; PS19/105; PS19/108; PS19/112; PS19/119; PS19/134; PS19/143; PS19/146; PS19 EPOS II; PS2111-2; PS2113-2; PS2114-2; PS2115-1; PS2117-1; PS2121-3; PS2122-1; PS2123-4; PS2128-1; PS2129-3; PS2130-2; PS2133-1; PS2134-1; PS2138-5; PS2144-3; PS2150-1; PS2153-1; Arctic; Arctic Ocean; Svalbard; Polar Biology; Spitsbergen
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.725786; https://doi.org/10.1594/PANGAEA.725786

Pore water and solid phase distributions of C, N, P and Si in sediments of the Arctic Ocean (Svalbard area) have been investigated. Concentrations of organic carbon (Corg) in the solid phase of the sediment varied from 1.3 to 2.8% (mean 1.9%), with highest concentrations found at shallow stations south/southwest of Svalbard. Relatively low concentrations were obtained at the deeper stations north/northeast of Svalbard. Atomic carbon to nitrogen ratios in the surface sediment ranged from below 8 to above 10. For some stations, high C/N ratios together with high concentrations of Corg suggest that sedimentary organic matter is mainly of terrigenous origin and not from overall biological activity in the water column. Organic matter reactivity (defined as the total sediment oxygen consumption rate normalized to the organic carbon content of the surface sediment) correlated with water depth at all investigated stations. However, the stations could be divided into two separate groups with different reactivity characteristics, representing the two most dominant hydrographic regimes: the region west of Svalbard mainly influenced by the West Spitsbergen Current, and the area east of Svalbard where Arctic polar water set the environmental conditions. Decreasing sediment reactivity with water depth was confirmed by the partitioning between organic and inorganic carbon of the surface sediment. The ratio between organic and inorganic carbon at the sediment-water interface decreased exponentially with water depth: from indefinite values at shallow stations in the central Barents Sea, to approximately 1 at deep stations north of Svalbard. At stations east of Svalbard there was an inverse linear correlation between the organic matter reactivity (as defined above) and concentration of dissolved organic carbon (DOC) in the pore water. The more reactive the sediment, the less DOC existed in the pore water and the more total carbonate (Ct or Sum CO2) was present. This observation suggests that DOC produced in reactive sediments is ...