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

本项目是对罗斯海生物硅和有机碳沉积速率、海底再生和沉积物积累研究的更新，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，这两个循环是分离的，因为现代沉积物中颗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的直接观测，于1989年至1991年期间进行。在这个项目中，沿着罗斯海的特定样带收集了盒状岩心、活塞岩心和岩溶岩心，其中包括富含二氧化硅和缺乏二氧化硅的沉积物。根据碳14年代学和海底生物成因二氧化硅和有机碳含量分析，确定了三个累积速率相差几个数量级的地点。在这些地点，生物硅和有机碳的海底保存效率存在很大差异。这项新的努力将涉及进一步分析两次巡航的数据，包括海底再生率、碳-14沉积物年表和水柱中生物物质的水平运输率，并将这些结果与其他合作调查人员正在完成的生产和垂直运输研究结合起来。

This project is the renewal of 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 particulate carbon deposition in the modern sediment is very low. The overall project is an integrated study of the 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, carried out between 1989 and 1991. In this project, box cores, piston cores, and kasten cores were collected along specific transects in the Ross Sea that included both silica-rich and silica-poor sediments. Based on carbon-14 chronologies and seabed analyses of biogenic silica and organic carbon content, three sites with accumulation rates differing by several orders of magnitude have been identified. At these sites large differences in seabed preservation efficiency exist for both biogenic silica and organic carbon. This renewed effort will be concerned with further analysis of data from the two cruises, including seabed regeneration rates, carbon-14 sediment chronologies, and horizontal transportation rates for biogenic material in the water column, and to integrate these results with production and vertical transport studies being completed by other cooperating investigators.