Evolution of postglacial landscapes and hydrological gateways in the Foxe Basin - Nettilling Lake region

北极的气候变暖速度超过了地球上的其他地区，正在进行的深刻的环境变化将放大全球变暖的趋势。了解北极气候和景观演变至关重要，以便能够预测未来的变化，并将其用于指导北方社区和自然资源的合理政策决策。 加拿大北极的气候历史并没有得到很好的理解。过去的气候数据提供了关于气候动态的宝贵见解，但北极历史记录稀少而简短。北部景观中有丰富的湖泊，其沉积物是过去环境变化的敏感档案，为未来更温暖的世界可能会是什么样子提供了令人信服的证据。 拟议的研究计划将采用严格的古陆相方法，将仪器记录置于长期视角中，并填补加拿大北部最难以进入的地区之一在气候和环境变化方面长期存在的知识空白。我的研究团队将使用多个替代指标重建过去的温度和其他环境变量，研究保存在北极群岛最大淡水分水岭Nettilling湖沉积物中的生物地层和地球化学记录，以及周围福克斯盆地的湖泊。将综合生成的古气候代理数据，以便与巴芬岛和格陵兰岛的冰芯数据以及区域古海洋学数据进行区域比较。将使用放射性碳和曝光技术绘制地表地貌图并确定年代，以确定冰川消退的位置和时间以及过去的海平面/湖面变化。多传感器岩心记录仪将提供沉积物地球化学和磁化率的高分辨率分析，并利用放射性和古地磁测年建立岩心年代学。 我们将测试各种硅质微体化石的d18O，作为追踪过去温度、盐度、水流和热结构变化的新指标，以阐明Nettilling湖盆地早期历史上的古水文门户和联系。我们的目标是为这些基于代理的信号如何由与过去气候变化相关的大气环流模式控制提供新的见解，并对未来气候情景下的生态系统建模产生影响。 拟议的研究将评估北极气候系统固有的关键阈值，并解决关于全新世气候变异性和敏感性以及冰川后冰川均衡动力学的基本问题。这些洞察力将极大地提高我们预测未来变化和对北方社区和基础设施的影响的能力。通过这项研究确定的历史基线条件将有助于制定政策，以适应加拿大北部迅速变化的气候和现代化。

Climate warming in the Arctic is outpacing the rest of the planet, and the profound environmental change underway will amplify warming trends with global impacts. Understanding Arctic climate and landscape evolution is critical so that future changes can be predicted and used to guide sound policy decisions for northern communities and natural resources. The climate history of the Canadian Arctic is not well understood. Past climate data offer valuable insights on climate dynamics, but Arctic historical records are sparse and short. Lakes are abundant in northern landscapes and their sediments are sensitive archives of past environmental changes that provide compelling evidence for what a future, warmer world might look. The proposed research program will apply a rigorous paleolimnological approach to place instrumental records into a long-term perspective and fill long-standing knowledge gaps on climate and environmental change in one of the most inaccessible regions of Canada's North. Using multiple proxies for reconstructions of past temperature and other environmental variables, my research team will study biostratigraphic and geochemical records preserved in the sediments of Nettilling Lake, the largest freshwater watershed in the Arctic Archipelago, as well as in lakes of the surrounding Foxe Basin. The paleoclimate proxy data generated will be synthesized to allow regional comparisons with ice core data from Baffin Island and Greenland and with regional paleoceanographic data. Surficial landforms will be mapped and dated using radiocarbon and exposure techniques to determine the position and timing of glacier retreat and past sea/lake level changes. Multi-sensor core loggers will provide high resolution analyses of sediment geochemistry and magnetic susceptibility, with core chronology established using radiometric and paleomagnetic dating. We will test d18O of various siliceous microfossils as a new proxy for tracking past changes in temperature, salinity, currents and thermal structure to elucidate paleohydrological gateways and connections during the early history of the Nettilling Lake basin. We aim to provide new insights into how these proxy-based signals are controlled by atmospheric circulation modes associated with past climate changes, with implications for modelling ecosystems under future climate scenarios. The proposed research will assess critical thresholds intrinsic to the Arctic climate system and address fundamental questions about Holocene climate variability and sensitivity, as well as postglacial glacio-isostatic dynamics. These insights will greatly improve our ability to anticipate future changes and impacts on northern communities and infrastructure. The historical baseline conditions established through this research will help develop policies for adaptation to a rapidly changing climate and modernization of Canada's North.