Selenium in Lake Sediments: A Measure of the Extent of Sea-Ice Cover

摘要ATM-9634345诺顿，斯蒂芬A。 乔治·雅各布森 缅因州大学题目：湖泊沉积物中的硒：海洋- 冰盖 古湖泊学和湖水化学研究表明：（1）单个湖泊沉积物中硒（Se）与有机质含量呈线性关系;（2）湖泊沉积物中Se的浓度与距外海的距离有关。 这种联系是通过从公海到湖盆集水区的海洋气溶胶中的硒和随后的硒（S的化学类似物）纳入有机物。 海洋气溶胶是大多数水生生态系统中硒的唯一重要来源。 该SGER奖支持调查沿海湖泊中Se浓度的地层变化，以记录与开阔海洋的距离变化并作为海冰覆盖的代理。 方法将涉及化学孢粉学和放射性分析（后者建立绝对年龄）的现有核心跨越全新世和核心跨越小时代到现在。 这将使该方法能够根据已知的气候变化和历史记录的海冰覆盖变化进行校准。

Abstract ATM-9634345 Norton, Stephen A. Jacobson, George L. University of Maine Title: Selenium in Lake Sediments: A Measure of the Extent of Sea- Ice Cover Several lines of paleolimnological and lake water chemistry research suggest that (1) selenium (Se) in lake sediments is linearly related to the percentage of organic matter for individual lakes and (2) normalized to organic matter concentration for lake districts, Se concentration is related to distance from the open ocean. The linkage is through the delivery of Se in marine aerosols from the open ocean to lake basin catchments and the subsequent incorporation of Se (a chemical analog for S) into organic matter. Marine aerosols are the only significant sources of Se to most aquatic ecosystems. This SGER award supports the investigation of stratigraphic variations in Se concentration in coastal lakes as a record of changing distance to open ocean and as a proxy for sea-ice cover. Methods will involve chemical palynological, and radiometric analyses (the later to establish absolute age) of existing cores spanning the Holocene and core spanning the Little Age to the present. This will enable calibration of the method against known climate variation and historically-documented variation in sea-ice cover.