Ice-Ocean-Atmosphere Interactions Along the East Greenland Margin on Decade to Century Timescales Over the Last 14 ka

主要研究人员将对东格陵兰大陆架的高分辨率ICOST（国际海洋全球变化研究）岩心进行详细研究。 长达25米的岩芯是在1999年北欧海第3和第4航段国际INUV巡航中，在国家科学基金会赠款的支持下，从特别有针对性的高分辨率地点收集的。 收集第四航段格陵兰岩芯是为了研究大陆架从退化到现在的气候和冰川历史。 这些地点是从以前收集的地震剖面和较短的重力岩心中选择的。 25米的高分辨率核心是前所未有的，可能代表最多过去14，000年。 最初的放射性碳和测年结果以及以前的工作表明，主要研究人员将能够解决十年到世纪时间尺度上发生的变化。 这些记录将为研究北极海冰和气候在各种环境条件下的自然变化提供极好的基础。 目标是记录东格陵兰海流的水文地理，包括其海冰覆盖和淡水流量，以及格陵兰冰盖和当地冰川在三个关键时间间隔内的相关变化。 它们将采用多种代用指标，这些代用指标已根据现代海洋学、生物学和沉积学数据进行了校准。 代理人包括：对底栖和浮游有孔虫进行氧和碳稳定同位素分析，底栖和浮游有孔虫组合，粒度变化（包括冰山筏状颗粒的量化），碳和碳酸盐通量变化，硅藻组合和丰度，岩相和古地磁强度记录。 主要调查人员将采用采样间隔，以提供关键时间段内发生的环境变化的十年至世纪尺度分辨率。 这些核心从大陆架地区直接影响北极海冰，快速沉积速率和相对海平面波动的影响很小，提供了令人兴奋的前景，了解北极海冰的自然变化，在EGC的属性，并在古海洋学，冰川历史和古气候的相互作用。

Abstract OPP-0082347The Principal Investigators will conduct a detailed study of high resolution IMAGES (International Marine Global Change Study) cores from the East Greenland continental shelf. Cores up to 25 m long were collected from specially targeted, high-resolution sites with support from a an NSF grant their partnership in the 1999 international IMAGES V cruise, Legs 3 and 4 in the Nordic Seas. The Leg 4 Greenland cores were collected for study of climate and glacial history of the shelf from degradation to the present. The sites were selected from seismic profiles and shorter gravity cores collected on previous. The 25 meter, high resolution cores are unprecedented in this are and likely represent at most the last 14,000 years. Initial radiocarbon and dating results and previous work indicate that the Principal Investigators will be able to resolve changes occurring on decade-to-century time scales. These records will provide an excellent basis for looking at the natural variability of sea ice and climate in the Arctic under a wide range of environmental conditions. The goal is to document the hydrography of the East Greenland Current, including its sea-ice cover and freshwater flux, and associated changes in the extent of the Greenland Ice Sheet and local glaciers during three critical time intervals. They will employ multiple proxies that have been calibrated to modem oceanographic, biological and sedimentological data. The proxies include: oxygen and carbon stable isotope analysis of benthic and planktonic foraminifers, benthic and planktic foraminiferal assemblages, grain-size changes (including quantification of iceberg rafted grains), carbon and carbonate flux changes, diatom assemblages and abundances lithofacies and paleomagnetic intensity records. The Principal Investigators will employ sampling intervals to provide decade to-century scale resolution of the environmental changes that have occurred through the critical time periods. These cores from a shelf area directly influenced by the arctic sea ice, rapid sedimentation rates and little influence of relative sea-level fluctuations offer exciting prospects for understanding natural variability in the Arctic sea ice, in the properties of the EGC, and in the interplay of paleoceanography, glacial history and paleoclimate.