Pore water geochemistry of Håkon Mosby mud volcano sediments measured at station MSM16/2_847-1 (Z2-S2, aged flow surface)

Pore water and turnover rates were determined for surface sediment cores obtained in 2009 and 2010. The pore water was extracted with Rhizons (Rhizon CSS: length 5 cm, pore diameter 0.15 µm; Rhizosphere Research Products, Wageningen, Netherlands) in 1 cm-resolution and immediately fixed in 5% zinc acetate (ZnAc) solution for sulfate, and sulfide analyses. The samples were diluted, filtered and the concentrations measured with non-suppressed anion exchange chromatography (Waters IC-Pak anion exchange column, waters 430 conductivity detector). The total sulfide concentrations (H2S + HS- + S**2-) were determined using the diamine complexation method (doi:10.4319/lo.1969.14.3.0454). Samples for dissolved inorganic carbon (DIC) and alkalinity measurements were preserved by adding 2 µl saturated mercury chloride (HgCl2) solution and stored headspace-free in gas-tight glass vials. DIC and alkalinity were measured using the flow injection method (detector VWR scientific model 1054) (doi:10.4319/lo.1992.37.5.1113). Dissolved sulfide was eliminated prior to the DIC measurement by adding 0.5 M molybdate solution (doi:10.4319/lo.1995.40.5.1011). Nutrient subsamples (10 - 15 ml) were stored at – 20 °C prior to concentration measurements with a Skalar Continuous-Flow Analyzer (doi:10.1002/9783527613984).本研究针对2009年与2010年采集的表层沉积物岩芯，测定了其孔隙水与周转速率。采用Rhizon采样器（Rhizon CSS：长度5 cm，孔径0.15 µm；荷兰瓦赫宁根根际研究产品公司（Rhizosphere Research Products, Wageningen, Netherlands））以1 cm的空间分辨率提取孔隙水，提取后立即将样品置于5%乙酸锌（ZnAc）溶液中固定，用于硫酸盐与硫化物分析。对样品进行稀释、过滤后，采用非抑制型阴离子交换色谱法（配备Waters IC-Pak阴离子交换柱与Waters 430型电导检测器）测定其浓度。总硫化物浓度（H₂S + HS⁻ + S²⁻）采用二胺络合法定量测定，相关方法参考文献DOI:10.4319/lo.1969.14.3.0454。用于溶解无机碳（DIC）与碱度测定的样品，通过添加2 µL饱和氯化汞（HgCl₂）溶液进行保存，并以无顶空的方式储存于气密玻璃小瓶中。采用流动注射法（检测器为VWR Scientific 1054型）测定DIC与碱度，方法来源DOI:10.4319/lo.1992.37.5.1113。在开展DIC测定前，需添加0.5 M钼酸盐溶液以去除样品中的溶解态硫化物，相关方法参考文献DOI:10.4319/lo.1995.40.5.1011。营养盐子样品（10~15 mL）先于–20 ℃下保存，后续采用Skalar连续流动分析仪测定其浓度，方法来源DOI:10.1002/9783527613984。