Late Quaternary Ice Sheet Extent, Chronology, and Paleoceanography, East Greenland Margin/Denmark Strait: Implictions for the Arctic and North Alantic Oceans

请求提供资金，以支持在美国/挪威联合研究巡航期间从格陵兰岛东部获得的沉积物岩芯研究。该建议的目标是：1)记录过去30ka格陵兰东部/丹麦海峡边缘冰盖/坡度/深海沉积物的转移和相互作用；2)测试关于上一次冰盛期期间东格陵兰冰盖边缘范围和退缩时间的不同假设；3)编制和解释至少在过去14ka地表水(东格陵兰洋流)和底层水(北极中间水)性质变化的高分辨率海洋记录，以及这些数据如何反映北冰洋和北大西洋的古海洋地貌变化。陆架和斜坡上的岩心从以前的调查和1996年采集岩心时都牢牢地置于地震地层格架中。选择核心地点的目的是：1)测试格陵兰东南部边缘冰川冰川范围的两个对比模型；2)调查记录期间(最后30 ka)跨越丹麦海峡北极和北大西洋“门户”的古海洋学和冰盖/海洋相互作用。上一次冰川期间，丹麦海峡两侧的东格陵兰冰缘的范围几乎是未知的，但这个冰川消融的程度和时间是了解丹麦海峡过去海洋环流变化的重要参数，以及这个冰缘在冰川时期海因里希事件、融化水峰和其他气候突变中所起的作用。全新世的研究重点是记录峡湾和大陆架上的古海洋学和冰川条件，并将这些重建与其他古气候数据进行比较，例如来自Renland冰芯的(18)记录，以及正在研究的来自陆地新冰川记录的“小冰期”事件。这些研究的结果将帮助我们了解该地区在全新世期间环境变化的方式、原因和速度。

Funding is requested to support research on sediment cores obtained from eastern Greenland during a joint USA/Norwegian research cruise. The objectives of the proposal are to: 1) Document ice sheet/slope/deep-sea sediment transfers and interactions for the East Greenland/Denmark Strait margin over the last 30ka; 2) Test different hypotheses for the extent of the East Greenland ice sheet's margin during the Last Glacial Maximum (LGM) and the timing of retreat; and 3) Develop and interpret high-resolution marine records (decadal to centuries time-scales) of changes in the character of the surface water (East Greenland Current) and bottom water (Arctic Intermediate Water) over at least the last 14ka, and how these data reflect paleoceanogrphic changes in the Arctic and North Atlantic Oceans. The core on the shelf and slope are firmly placed in a seismic stratigraphic framework both from previous surveys and during core collection in 1996. The choice of the core sites was designed to 1) test two contrasting models for the extent of glacial ice on the south-central east Greenland margin during and since the LGM and to 2) investigate the paleoceanography and ice-sheet/ocean interactions across the Denmark Strait "gateway" between the Arctic and the North Atlantic over the interval of record (the last 30 ka). The extent of the East Greenland ice margin flanking Denmark Strait during the last glaciation is virtually unknown, yet this extent and the timing of deglaciation are important parameters for understanding the past changes in ocean circulation through the Denmark Strait, and the role of this ice margin in Heinrich events, meltwater spikes, and other abrupt climate changes during the glacial period. The research thrust for the Holocene is to document paleoceanographic and glacial conditions in the fjords and on the shelf, and to compare these reconstructions with other paleoclimate data such as the ( 18( record from Renland ice core, and the "Little Ice Age" events under study from the t errestrial neoglacial record. The results of these studies will help us to understand how, why, and how quickly the environment has changed in this region during the Holocene.