Ostracode Mg/Ca Paleothermometry in the Arctic Ocean: A Calibration Study

北冰洋 Ostracode Mg/Ca 古体温测量：校准研究

• 批准号: 0223097
• 负责人: Gary Dwyer
• 金额: $ 7.4万
• 依托单位: Duke University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-08-15 至 2003-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0223097&HistoricalAwards=false
• 关键词: Ostracode; Mg; Ca; Paleothermometry; Arctic

0223097 DwyerThe Principal Investigator will undertake core-top calibration studies to improve the applicability, accuracy, and precision of ostracode magnesium/calcium (Mg/Ca) paleothermometry to reconstruct the late Quaternary temperature history of the Arctic Ocean and adjacent seas. The existing core-top calibration is limited to adult shells of one genus, Krithe, and includes sediment core tops that are not likely to be of modern age. These factors, along with variations in the spatial and temporal abundance of adult shells of Krithe in the Arctic, contribute to diminish the accuracy, precision (1 to 20C, depending on number of shells available), and applicability of ostracode paleothermometry in the Arctic Ocean. However, studies suggest that the adult shells of other common Arctic genera may also be used for Mg/Ca paleothermometry, and, furthermore, that eldest juvenile shells display thermodependent uptake of magnesium identical to that of adult shells. If so, the combination of juvenile/adult calibrations and calibrations from multiple genera may provide the improvements necessary to more accurately and precisely quantify the temperature history of the Arctic Ocean and adjacent seas. To test this hypothesis, modern adult and juvenile shells of common Arctic genera Krithe and Cytheropteron will be analyzed from an extensive collection of existing, high-quality sediment core tops (box cores and multicores) from Arctic, Atlantic, and Pacific ocean basins at water temperatures ranging from -1 to 120C. A subset of these core tops have been used for benthic foraminifer Mg/Ca calibration studies. The research will provide for the first comprehensive calibration-comparison of the two most promising deep-sea paleothermometers available for paleoceanographic and paleoclimate studies.

0223097 首席研究员将进行核心顶部校准研究，以提高介形虫镁/钙（Mg/Ca）古温度测量的适用性，准确性和精密度，以重建北冰洋和邻近海域的晚第四纪温度历史。现有的岩心顶部校准仅限于一个属的成年贝壳，Krithe，包括沉积物岩心顶部，不太可能是现代的。这些因素，沿着在空间和时间上的变化，丰富的成年克瑞斯在北极，有助于减少准确性，精度（1至20摄氏度，取决于壳的数量），并在北冰洋介形虫古温度计的适用性。 然而，研究表明，其他常见北极属的成年贝壳也可用于镁/钙古温度测量，此外，最年长的幼年贝壳对镁的热依赖性吸收与成年贝壳相同。如果是这样的话，青少年/成人校准和校准从多个属的组合可以提供必要的改进，更准确和精确地量化北冰洋和邻近海域的温度历史。 为了验证这一假设，现代成人和少年壳常见的北极属Krithe和Cytheropteron将分析现有的，高品质的沉积物芯顶部（箱芯和多芯）从北极，大西洋和太平洋盆地在水温范围从-1到120 ℃的广泛收集。这些岩心顶部的一个子集已被用于底栖有孔虫镁/钙校准研究。 这项研究将首次对两个最有希望用于古海洋学和古气候研究的深海古温度计进行全面校准比较。