Particulate geochemistry of sediment core AL561_7-1@en

The AL561 cruise was conducted in the framework of the project APOC (\"Anthropogenic impacts on Particulate Organic Carbon cycling in the North Sea\"). This collaborative project between GEOMAR, AWI, HEREON, UHH, and BUND is to understand how particulate organic carbon (POC) cycling contributes to carbon sequestration in the North Sea and how this ecosystem service is compromised and interlinked with global change and a range of human pressures include fisheries (pelagic fisheries, bottom trawling), resource extraction (sand mining), sediment management (dredging and disposal of dredged sediments) and eutrophication. The main aim of the sampling activity during AL561 cruise was to recover undisturbed sediment from high accumulation sites in the Skagerrak/Kattegat and to subsample sediment/porewater at high resolution in order to investigate sedimentation transport processes, origin of sediment/POC and mineralization processes over the last 100- 200 years. Moreover, the actual processes of sedimentation and POC degradation in the water column and benthic layer will be addressed by sampling with CTD and Lander devices. In total 9 hydroacoustic surveys (59 profiles), 4 Gravity Corer, 7 Multicorer, 3 BIGO Lander and 3 CTD stations were successfully conducted during the AL561 cruise.AL561航次依托APOC项目开展，该项目英文全称为"Anthropogenic impacts on Particulate Organic Carbon cycling in the North Sea"，中文译名为"人类活动对北海颗粒有机碳循环的影响"。该项目由GEOMAR、AWI、HEREON、UHH与BUND联合实施，旨在阐明颗粒有机碳（Particulate Organic Carbon, POC）循环对北海碳封存的贡献机制，以及该生态系统服务如何受到全球变化与一系列人类活动压力的影响与削弱——这些压力包括渔业（远洋渔业、底拖网捕捞）、资源开采（采砂作业）、沉积物管理（疏浚及疏浚物处置）以及水体富营养化。AL561航次的取样工作核心目标为：从斯卡格拉克海峡/卡特加特海峡的高沉积速率站位采集未受扰动的沉积物，并对沉积物/孔隙水开展高分辨率分样，以解析近100至200年间的沉积物搬运过程、沉积物/POC来源与矿化过程。此外，本航次还将借助温盐深剖面仪（Conductivity, Temperature, Depth, CTD）与着陆器（Lander）设备开展取样作业，以解析水体与底栖层内的实际沉积过程与POC降解机制。AL561航次期间共顺利完成9次水声调查（共59条测线）、4台重力柱状取样器作业、7台多管取样器作业、3台BIGO着陆器部署与3个CTD测站作业。