Pore-water geochemistry of surface sediments retrieved from the eastern continental shelf of the Antarctic Peninsula during RV POLARSTERN cruise PS118

During the PS118 research cruise with the German research vessel RV POLARSTERN (Feb 2019- April 2019), sediments were collected with a multicorer from 7 stations along a 400 mile transect from the eastern shelf of the Antarctic Peninsula to the West of the South Orkney Islands. A total of 69 high-resolution O2 profiles were measured in 23 cores in the upper sediment layer using optical microsensors (Optodes, Pyroscience) in order to determine oxygen penetration depths and 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 30 cm. Sediments of parallel cores were cut at the same depth resolution for solid-phase contents. Pore-water analyses of trace element such as dissolved iron (DFe) and manganese (DMn), dissolved inorganic carbon (DIC), hydrogen sulfide (H2S) and nutrients such as ammonium (NH4+), phosphate (PO4³), nitrate (NO3-), nitrite (NO2-) and silicate (SiO3²−) were measured. For solid-phase analyses, freeze-dried and ground sediment samples were measured for TOC and TN. At 5 stations, Al, Fe, Mn, P and S content was measured after total acid digestion. At the same 5 stations, excess 210Pb was measured in freeze-dried and homogenized sediments.