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

0124014霍尔该奖项支持一个项目，旨在加深人们对冰川周期驱动因素的理解。大多数研究人员都同意，米兰科维奇的季节性强迫加快了冰河时代的步伐，但这些日照变化如何被利用到突然的全球气候变化中仍是未知的。目前流行的一种观点是，南极洲和南大洋的气候在第一个终结点比世界其他地区早几千年，在之前的终止点比世界其他地区更大的差距。该项目将把冰川历史的地貌记录与从南极洲麦克默多海湾地区干燥山谷的湖底采集的一系列岩芯结合起来。使用改进的Livingstone取样器，将从Fryxell湖、Bonney湖、Joyce湖和Vanda湖获得长岩心的横断面。将使用一种多参数方法，旨在从干燥的山谷湖泊中提取尽可能多的以前的水位、冰川和古环境数据。对水文变化的估计将来自不同的指标，包括粒度、地层、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。为了将岩芯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，所需的年表将来自碳酸盐的铀-钍、铀-氦和碳-14测年，以及发光沉积物测年。对湖泊水位和气候之间的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，将产生一个可追溯到至少30,000年前的南极湖泊水位和古气候综合数据集。这一记录将与干旱山谷冰川记录和南极冰芯进行比较，以解决区域气候变异性的问题，然后与南半球和北半球的其他记录进行比较，以评估气候变化的半球间同步性或异步性

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