Characterizing the Composition, Flux, and Temporal Variability of Terrigenous Sources to the Cariaco Basin: Relationship to Climate Variability

热带辐合带（ITCZ）的纬度变化改变了陆源沉积，无论是河流沉积还是风成沉积。例如，在北半球冬季，由于强烈的偏东信风，北太平洋与北太平洋的南移与较高的风成输入相一致，而在夏季北太平洋与北太平洋的北移期间，观察到较高的河流输入。来自波士顿大学的一名科学家将对从卡里亚科盆地的沉积物捕集器阵列中回收的样品进行地球化学研究，以确定化学成分和陆源成分总通量的季节变化特征。在五年的时间里，将对圈闭中回收的物质进行主要、痕量和稀土元素以及放射性同位素的分析。化学成分和总通量的变化将作为降水、风应力和上升流的函数进行评估，以了解现代过程如何控制现场的陆源变率。此外，该项目还将通过收集委内瑞拉沿海大陆架、当地河流、巴巴多斯风成样品以及来自奥里诺科河的材料来补充水柱工作，以限制可能的末端成员来源。就更广泛的影响而言，这项研究的结果将进一步加深我们对ITCZ变化如何改变陆源物质输入的理解，这反过来可以提供有关热带纬度全球气候变化的信息。该项目利用的样本是委内瑞拉海岸外加勒比合作组织时间序列的一部分，是委内瑞拉和美国科学家之间的合作成果。一名来自委内瑞拉的研究生将作为这项研究的一部分接受培训和支持。

ABSTRACTOCE-0451775Terrigenous deposition, either fluvial or aeolian, is altered by latitudinal shifts in the Intertropical Convergence Zone (ITCZ). For example, a southern shift in the ITCZ during the Northern Hemisphere winter coincides with higher aeolian inputs in response to strong easterly trade winds, whereas during the northern migration of the ITCZ in the summer, higher fluvial inputs are observed. A scientist from Boston University will carry out a geochemical study of samples recovered from a sediment trap array in the Cariaco Basin to characterize seasonal changes in the chemical composition and total flux of the terrigenous component. Material recovered in the traps over a five year period will be analyzed for major, trace and rare earth elements, as well as radiogenic isotopes. Changes in chemical composition and total flux will be assessed as a function of precipitation, wind stress, and upwelling to understand how modern processes control the terrigenous variability at the site. In addition, this PI will complement the water column work by collecting samples along the Venezuelan coastal shelf, local rivers, Aeolian samples from Barbados, and material derived from the Orinoco River to constrain possible end-member sources. In terms of broader impacts, results from this study will further our understanding of how changes in the ITCZ alters inputs of terrigenous material which in turn can provide information on global climate variations in tropical latitudes. The project utilizes samples collected as part of the CARIACO time series off the coast of Venezuela and is a collaborative effort between Venezuelan and U.S. scientist. A graduate student from Venezuela will be trained and supported as part of this study.