Collaborative Research: Millennial-Scale Fluctuations of Dry Valleys Lakes: Implications for Regional Climate Variability and the Interhemispheric (a)Synchrony of Climate Change

[124014]霍尔该奖项支持一个项目，以增加对驱动冰川循环的理解。大多数研究人员都同意米兰科维奇季节强迫加快了冰河时代的步伐，但这些日照变化是如何影响到突然的全球气候变化的仍不得而知。目前流行的一种观点是，南极洲和南大洋的气候在第一终点领先世界其他地方两千年，在以前的终点领先的幅度更大。这个项目将把冰川历史的地形学记录与从南极洲麦克默多海湾地区的干谷湖底采集的一系列岩心结合起来。使用改良的Livingstone覆盖，将从Fryxell湖、Bonney湖、Joyce湖和Vanda湖获得长岩心的横断面。将采用一种多参数方法，旨在从干谷湖泊中提取尽可能多的前水位、冰川学和古环境数据。水文变化的估计将来自不同的指标，包括粒度、地层学、蒸发岩矿物学、稳定同位素和微量元素化学以及硅藻组合分析。将岩心与地貌记录结合起来，以及与南极冰芯和冰川记录进行比较所必需的年代学，将来自碳酸盐的铀-钍、铀-氦和碳-14定年，以及发光沉积物定年。对湖泊水位与气候之间联系的评估将来自水文和能量平衡模型。将更连续的湖芯序列与空间上广泛的地貌记录相结合，将得到一个至少可追溯到3万年的完整的南极湖平面和古气候数据集。该记录将与干谷冰川记录和南极冰芯进行比较，以解决区域气候变率的问题，然后与南半球和北半球的其他记录进行比较，以评估半球间气候变化的同步或非同步

0124014 HallThis award supports a project to add to the understanding of what drives glacial cycles. Most researchers agree that Milankovitch seasonal forcing paces the ice ages but how these insolation changes are leveraged into abrupt global climate change remains unknown. A current popular view is that the climate of Antarctica and the Southern Ocean leads that of the rest of the world by a couple thousand years at Termination I and by even greater margins during previous terminations. This project will integrate the geomorphological record of glacial history with a series of cores taken from the lake bottoms in the Dry Valleys of the McMurdo Sound region of Antarctica. Using a modified Livingstone corer, transects of long cores will be obtained from Lakes Fryxell, Bonney, Joyce, and Vanda. A multiparameter approach will be employed which is designed to extract the greatest possible amount of former water-level, glaciological, and paleoenvironmental data from Dry Valleys lakes. Estimates of hydrologic changes will come from different proxies, including grain size, stratigraphy, evaporite mineralogy, stable isotope and trace element chemistry, and diatom assemblage analysis. The chronology, necessary to integrate the cores with the geomorphological record, as well as for comparisons with Antarctic ice-core and glacial records, will come from Uranium-Thorium, Uranium-Helium, and Carbon-14 dating of carbonates, as well as luminescence sediment dating. Evaluation of the link between lake-level and climate will come from hydrological and energy-balance modelling. Combination of the more continuous lake-core sequences with the spatially extensive geomorphological record will result in an integrated Antarctic lake-level and paleoclimate dataset that extends back at least 30,000 years. This record will be compared to Dry Valleys glacier records and to the Antarctic ice cores to address questions of regional climate variability, and then to other Southern Hemisphere and Northern Hemisphere records to assess interhemispheric synchrony or asynchrony of climate change