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

要求提供经费，以支助对美国/挪威联合研究巡航期间从格陵兰东部取得的沉积物岩心进行研究。该提案的目标是：1)记录过去30ka东格陵兰/丹麦海峡边缘的冰盖/斜坡/深海沉积物转移和相互作用；2)对末次盛冰期（LGM）东格陵兰冰盖边缘范围和退缩时间的不同假设进行检验；3)开发和解释至少过去14ka的地表水（东格陵兰流）和底水（北极中间水）特征变化的高分辨率海洋记录（年代际到世纪时间尺度），以及这些数据如何反映北极和北大西洋的古海洋学变化。从以前的调查和1996年的岩心收集中，陆架和斜坡上的岩心被牢固地放置在地震地层格架中。核心点的选择旨在1)测试两个对比模型，以确定格陵兰岛中南部东部边缘在LGM期间和自LGM以来的冰川覆盖范围；2)研究有记录以来（最近30 ka）横跨北极和北大西洋之间的丹麦海峡的古海洋学和冰盖/海洋相互作用。末次冰期丹麦海峡两侧的东格陵兰冰缘的范围实际上是未知的，但这一范围和消冰期的时间是理解过去通过丹麦海峡的海洋环流变化的重要参数，以及这一冰缘在海因里希事件、融水峰值和冰期其他气候突变中的作用。全新世的研究重点是记录峡湾和冰架上的古海洋学和冰川条件，并将这些重建结果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地球新冰川记录的“小冰期”事件。这些研究的结果将帮助我们理解全新世期间该地区环境变化的方式、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.