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

描述卡里亚科盆地陆源的成分、通量和时间变化：与气候变化的关系

• 批准号: 0451775
• 负责人: Richard Murray
• 金额: --
• 依托单位: Trustees of Boston University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-06-01 至 2011-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0451775&HistoricalAwards=false
• 关键词: Characterizing; Composition; Flux; Temporal; Variability

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.

陆源沉积，无论是河流沉积还是风成沉积，都会受到热带辐合带(ITCZ)纬向变化的影响。例如，北半球冬季ITCZ的南移与较高的风沙输入相吻合，而在夏季ITCZ向北迁移时，观测到较高的河流输入。波士顿大学的一名科学家将对从卡里亚科盆地沉积物圈闭阵列中发现的样本进行地球化学研究，以表征陆源成分的化学成分和总通量的季节性变化。在五年的时间里，将对圈闭中回收的材料进行常量、微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化。此外，该PI将通过收集委内瑞拉沿海陆架、当地河流的样品、巴巴多斯的风尘样品和来自奥里诺科河的物质来补充水柱工作，以限制可能的终端成员来源。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，这些输入反过来可以提供关于热带纬度全球气候变化的信息。该项目利用了委内瑞拉海岸外Cariaco时间序列收集的样本，是委内瑞拉人和美国科学家的合作成果。作为这项研究的一部分，一名来自委内瑞拉的研究生将接受培训和支持。