Oxygen profiles and pore-water geochemistry of surface sediments collected from the southern Weddell Sea shelf@en

During the PS111 research cruise with the German research vessel RV POLARSTERN (January 2018- March 2018), sediments were collected with a multicorer from 15 stations, i.e., four on the eastern Weddell Sea shelf at 387 to 663 m water depth, five in the Filchner Trough at 794 to 932 m water depth, and four along the western Weddell Sea shelf at 332 to 660 m water depth. Two deeper stations were located on the eastern Weddell Sea slope at 1405 and 1775 m water depth. A total of 28 high-resolution O2 profiles were measured in the upper sediment layer using optical microsensors (Optodes, Pyroscience) in order to determine diffusive oxygen uptake (DOU). Pore-water samples were taken at depth resolutions of 1 cm from 0-10 cm and below 10 cm with a resolution of 2 cm down to a maximum depth of 35 cm. Pore-water analyses of dissolved iron (DFe), manganese (DMn), sulfate (SO42-), and nutrients such as ammonium (NH4+), phosphate (PO43-), nitrate (NO3-), nitrite (NO2-), and silicate (SiO32−) were measured.在德国科考船RV POLARSTERN执行的PS111科考航次（2018年1月—2018年3月）期间，研究人员使用多管取样器（multicorer）在15个站位采集了沉积物柱样：其中4个站位位于威德尔海东部陆架，水深387至663米；5个站位位于菲尔希纳海槽（Filchner Trough），水深794至932米；4个站位沿威德尔海西部陆架分布，水深332至660米；另有2个深水站位位于威德尔海东部陆坡，水深分别为1405米和1775米。 研究人员使用光学微传感器（optical microsensors，Optodes，Pyroscience）在沉积物上层共测得28条高分辨率氧气剖面，以测定扩散耗氧量（diffusive oxygen uptake, DOU）。沉积物孔隙水样品的采集垂向分辨率为：0至10厘米层段采用1厘米间隔，10厘米以下至最大35厘米层段则采用2厘米间隔。随后对孔隙水中的溶解态铁（dissolved iron, DFe）、溶解态锰（dissolved manganese, DMn）、硫酸盐（SO₄²⁻）以及铵态氮（NH₄+）、磷酸盐（PO₄³⁻）、硝酸盐（NO₃-）、亚硝酸盐（NO₂-）和硅酸盐（SiO₃²−）等营养盐组分开展了检测分析。