Organic carbon flux and oxygen penetration into sediments of the Weddell Sea: indicators for regional differences in export production

• Published in: Marine Chemistry
• Main Author: Schlüter, Michael
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 1991
• Subjects: Antarctic; Filchner Ice Shelf; Weddell; Weddell Sea; Antarc*; Ice Shelf
• Online Access: https://oceanrep.geomar.de/id/eprint/47057/; https://oceanrep.geomar.de/id/eprint/47057/1/1-s2.0-S0304420309900433-main.pdf; https://doi.org/10.1016/S0304-4203(09)90043-3

The flux of reactive organic carbon (C(org)) into sediments of the southern and eastern Weddell Sea was estimated by modelling measured oxygen and nitrate pore-water profiles. Highest flux of reactive organic carbon into the sediment was calculated for the shelf region (500 and 600 mmol C m-2 year-1), whereas for pelagic and continental slope sediments C(org) fluxes of less than 60 mmol C m-2 year-1 and 100-200 mmol C m-2 year-1 respectively were calculated. The oxygen penetration depth (OPD) ranged from less than 2 cm in shelf sediments to much greater than 40 cm in pelagic sediments. For the first time, sediments covered by the Filchner Ice Shelf (probably cut off from a source of primary production for a few decades) were sampled. In this area a restricted vertical flux of reactive organic carbon was expected. However, the C(org), content of these sediments was as high as that of Antarctic shelf sediments, which suggests lateral transport of organic matter. In contrast, pore-water profiles and calculated reactive organic carbon fluxes off Filchner Ice Shelf are similar to those of much deeper depositional environments (3000-4000 m water depth).