The Preservation and Accumulation of Biogenic Silica and Organic Carbon in a High-Latitude Environment: The Ross Sea

本项目研究的是罗斯海生物硅和有机碳的沉积速率、海底再生和沉积物积累，是罗斯海水柱和沉积物中生物硅和有机碳循环协调研究的一部分。南极深海和大陆架环境是全球海洋二氧化硅积累的主要储存库，并主导着全球二氧化硅收支。罗斯海是一个特别反常的地区，在那里，大量的生物成因二氧化硅积聚在现代沉积物中，而表面的生产速度通常低于全球平均水平。此外，海洋硅和碳循环之间通常的相似性似乎在南极洲周围并不成立，而且这两个循环是分离的，因为现代沉积物中微粒碳沉积的速率非常低。整个项目是对生产、垂直输送、溶解和沉积过程的综合研究，使用系泊仪器和由R/V POLAR DUKE在罗斯海的一系列样带进行直接观测。量化海底过程速率的方法将是沿着罗斯海的特定样带收集盒状岩心、活塞岩心和喀斯特岩心，这些样带包括富含二氧化硅和缺乏二氧化硅的沉积物。将通过测量溶解二氧化硅、二氧化碳、氨和氮、硫酸盐和磷酸盐的孔隙-水剖面来评估海底二氧化硅的溶解和有机碳的降解。累积速率将根据放射化学年表确定。这些海底研究将为地面生产研究和水柱通量研究提供结束，这些研究将由在这个项目中合作的其他调查人员进行。

This project is a study of the rates of deposition, seabed regeneration, and sediment accumulation of biogenic silica and organic carbon in the Ross Sea, and is part of a coordinated study of the biogenic silica and organic carbon cycling in the water column and the sediments of the Ross Sea. The antarctic deep sea and continental shelf environment is the major repository for silica accumulation in the global ocean, and dominates the global silica budget. The Ross Sea is a particularly anomalous area in which large amounts of biogenic silica are accumulating in modern sediments, while the surface production rates are generally below the global average. Moreover the usual similarity between the oceanic silicon and carbon cycle does not appear to hold around Antarctica, and the two cycles are decoupled in that the rate of particulatew carbon deposition in the modern sediment is very low. The overall project is an integrated study of production, vertical transport, dissolution, and deposition processes, using moored instrumentation and direct observations in a series of transects in the Ross Sea by R/V POLAR DUKE. The approach to be used to quantify the rates of bottom processes will be to collect box cores, piston cores, and kasten cores along specific transects in the Ross Sea that included both silica-rich and silica- poor sediments. Seabed dissolution of silica and degradation of organic carbon will be evaluated by measuring pore-water profiles of dissolved silica, carbon dioxide, amonia and nitrogen species, sulfates, and phosphates. Accumulation rates will be determined from radiochemical chronologies. These sea-floor studies will provide the closure for the surface production studies and the water column flux studies that will be carried out by other investigators cooperating in this project.