Collaborative Research: Paired Neodymium Isotope and Radiocarbon Analyses in Deep-Sea Corals - Calibration of a Novel Ocean Ventilation Tracer

合作研究：深海珊瑚中的配对钕同位素和放射性碳分析 - 新型海洋通风示踪剂的校准

• 批准号: 0623107
• 负责人: Robert Anderson
• 金额: --
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-09-01 至 2008-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0623107&HistoricalAwards=false
• 关键词: Collaborative; Research; Paired; Neodymium; Isotope

Collaborative Research: Paired Neodymium Isotope and Radiocarbon Analyses in Deep-Sea Corals Calibration of a Novel Ocean Ventilation TracerOcean ventilation rates describe the time since a deep water mass last was in contact with the atmosphere. Understanding and constraining this time in the modern and past ocean is of major importance, as the formation of deep waters at high latitudes involves carbon exchange with the atmosphere thereby exerting a key influence on climate. The research proposed here will develop a novel method for determining past ocean ventilation rates: paired neodymium (Nd) isotope and radiocarbon (14C) measurements from deep-sea corals. Radiocarbon measurements in U-series dated deep-sea corals have been successfully used to constrain the radiocarbon content of the deep ocean during the last deglaciation, but without knowing the mixing ratio of different water masses we cannot convert radiocarbon data to ocean ventilation rates. Different water masses in the ocean are characterized by distinct Nd isotopic compositions, whose values are ultimately controlled by regional continental weathering, erosion, and particle-seawater interaction. Therefore this proxy will be used as a quasi-conservative water-mass-mixing tracer.In this project, the PIs will evaluate whether different species of modern deep-sea corals record the Nd isotopic composition of ambient deep water, and whether fossil corals preserve this Nd isotope signature. These data have the potential to produce a new method for accurately determining past ocean ventilation rates. The results of this multiproxy approach have the potential to provide links between ocean ventilation, the carbon cycle, and climate change for researchers studying a broad array of questions in the fields of carbonate chemistry, geochemical cycling in the ocean, the global carbon cycle and paleoceanography. Undergraduate students on summer internships will be introduced to the fields of paleoceanography and geochemistry through discrete projects involving analytical measurements in modern and fossil deep-sea corals.

合作研究：深海珊瑚中的成对Neo同位素和放射性碳分析一种新的海洋通风示踪剂的校准海洋通风率描述了自深海水体最后一次与大气接触以来的时间。理解和限制现代和过去海洋中的这一时间具有重大意义，因为高纬度深水沃茨的形成涉及与大气的碳交换，从而对气候产生关键影响。这里提出的研究将开发一种新的方法来确定过去的海洋通风率：成对的钕（Nd）同位素和深海珊瑚的放射性碳（14 C）测量。放射性碳测量的U系列定年深海珊瑚已被成功地用于限制在最后一次冰消期深海的放射性碳含量，但不知道不同的水质量的混合比，我们不能将放射性碳数据转换为海洋通风率。大洋中不同水团具有不同的Nd同位素组成特征，其值最终受控于区域大陆风化、侵蚀和颗粒-海水相互作用。因此，这一代用指标将被用作准保守的水团混合示踪剂。在本项目中，研究人员将评估不同种类的现代深海珊瑚是否记录了周围深水的Nd同位素组成，以及珊瑚化石是否保留了这种Nd同位素特征。这些数据有可能产生一种新的方法来准确地确定过去的海洋通风率。这种多代理方法的结果有可能为研究碳酸盐化学，海洋地球化学循环，全球碳循环和古海洋学领域的广泛问题的研究人员提供海洋通风，碳循环和气候变化之间的联系。暑期实习的本科生将通过涉及现代和化石深海珊瑚分析测量的离散项目被引入古海洋学和地球化学领域。