Collaborative Research: Particulate Organic Carbon Fluxes and Sediment Accumulation in the Cariaco Basin

Cariaco盆地是委内瑞拉外大陆架上一个1400米深的洼地，其缺氧水体覆盖着有机质含量高（1-5 wt%）的层状沉积物。这些纹层是由初级生产力的季节变化和沿加勒比海南部的陆源沉积物输入造成的，包含了热带大西洋过去气候变化的高分辨率记录。在这项合作中，南佛罗里达大学（USF）、南卡罗来纳大学（USC）和纽约州立大学（SUNY）的研究人员试图将卡里亚科盆地的水文、初级生产力、水柱微生物活动、垂直颗粒通量和沉积物积累率测量结果整合到一个综合研究中，以了解当代沉积模式如何反映这种气候和海洋学变化。中心目标是了解控制Cariaco盆地初级生产与颗粒垂直通量之间关系的因素。这个项目将继续目前在北纬10′30′、西经64′40′的每月观测时间序列，该序列自1995年11月开始，是根据CARIACO（有色海洋碳保留）计划进行的。这包括继续部署一个系泊装置，其中包含四个沉积物收集器（275、350、450和1200米），以便每两周在每个深度收集样本。与捕集器相辅相成的是两个声学多普勒电流分析器（ADCP）的系泊，一个从250米的深度向上观测，另一个从250米的深度向下观测，测量从静止深度以下到水面的电流，为期三年。每年，将在CARIACO站和盆地外北纬11′40′、西经64′40′之间进行一个样带，以帮助了解涉及入侵和上升流的水源的特征。将使用当地和遥感数据检查区域风和海平面，以确定上升流的强迫是否主要通过当地或环流尺度过程发生。通过对Cariaco盆地沉积物的收集和分析，可以重建Cariaco盆地过去一个世纪的海洋条件，并为更长期的古海洋学研究提供一个窗口。该项目意义重大，因为它为正确解释卡里亚科沉积物中记录的过去气候变化提供了必要的基础真相。

ABSTRACTOCE-0118491The Cariaco Basin is a 1,400-m deep depression on the continental shelf off Venezuela in which anoxic waters cover laminated sediments with high organic matter content (1-5 wt%). These laminae, which result from seasonal variations in primary productivity and terrigenous sediment input along the southern the Caribbean Sea, contain a high-resolution record of past climate change in the tropical Atlantic Ocean. In this collaborative effort, researchers at the University of South Florida (USF), the University of South Carolina (USC), and the State University of New York (SUNY) seek to integrate hydrographic, primary productivity, water column microbial activity, vertical particulate flux, and sediment accumulation rate measurements in the Cariaco Basin into a synthesis to understand how contemporary sedimentation patterns reflect this climatic and oceanographic variability. The central objective is to understand the factors that control the relationship between primary production and the vertical flux of particles in the Cariaco Basin. This project will continue the current time series of monthly observations at 10'30' N, 64'40' W that began in November, 1995, under the CARIACO (CArbon Retention In A Colored Ocean) Program. This includes continuing deployment of a mooring with four sediment traps (275, 350, 450, and 1,200 m) to provide bi-weekly sample collections at each depth. Complementing the traps will be a mooring with two Acoustic Doppler Current Profilers (ADCP), one looking up and the other looking down from a depth of about 250 m, to measure currents from below the sill depth to the surface for a three-year period. Each year, one transect will be conducted between the CARIACO station and 11'40' N, 64'40' W outside the basin, to help understand the characteristics of source water involved in intrusions and upwelling. Regional wind and sea level will be examined using both local and remotely-sensed data to establish whether forcing for upwelling occurs primarily through local or gyre-scale processes. Sediments from the Cariaco basin will be collected and analyzed to reconstruct the oceanographic condition in the Cariaco Basin over the past century and provide a window for longer-scale paleoceanographic studies. The program is significant because it provides groundtruthing needed for proper interpretation of past climate changes recorded in the Cariaco sediments.