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

北极地区的气候变暖速度超过全球其他地区，正在发生的深刻环境变化将放大气候变暖趋势，并对全球产生影响。了解北极气候和景观演变至关重要，这样才能预测未来的变化，并用于指导针对北方社区和自然资源的合理决策。*加拿大北极地区的气候历史尚不清楚。过去的气候数据为气候动力学提供了有价值的见解，但北极的历史记录既稀少又短暂。北方地区湖泊丰富，其沉积物是过去环境变化的敏感档案，为未来变暖的世界提供了令人信服的证据。*******拟议的研究计划将采用严格的古湖泊学方法，将仪器记录置于长期视角，并填补加拿大北部最难以进入的地区之一的气候和环境变化方面长期存在的知识空白。我的研究小组将使用多种代理来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的淡水流域Nettilling湖以及周围Foxe盆地湖泊沉积物中的生物地层和地球化学记录。生成的古气候代理数据将进行综合，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。地表地貌将被绘制出来，并使用放射性碳和暴露技术确定年代，以确定冰川退缩和过去海平面/湖泊水位变化的位置和时间。多传感器岩心记录仪将提供高分辨率的沉积物地球化学和磁化率分析，并使用放射性和古地磁测年法建立岩心年代学。*******我们将测试各种硅质微化石的d18O，作为追踪过去温度、盐度、水流和热结构变化的新代理，以阐明Nettilling湖盆地早期历史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受到与过去气候变化相关的大气环流模式的控制提供新的见解，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临界阈值，并解决有关全新世气候变率和敏感性以及冰期后冰川均衡动力学的基本问题。这些见解将大大提高我们预测未来变化及其对北部社区和基础设施的影响的能力。通过这项研究建立的历史基线条件将有助于制定适应快速变化的气候和加拿大北部现代化的政策

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.***