Collaborative Research: Development of paleo-proxy to test the sensitivity of the Southern Greenland Ice Sheet to future warming

合作研究：开发古代理来测试格陵兰冰盖南部对未来变暖的敏感性

• 批准号: 0902571
• 负责人: Brian Beard
• 金额: $ 46.11万
• 依托单位: University of Wisconsin-Madison
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-15 至 2013-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0902571&HistoricalAwards=false
• 关键词: Collaborative; Research; Development; paleo; proxy

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).Carlson 0902571University of Wisconsin ? MadisonA significant missing component in paleo-reconstructions of GIS behavior has been the lack of an unambiguous ice sheet tracer. The development of such a tracer for the Greenland Ice Sheet (GIS) retreat and aerial extent is proposed using terrigenous provenance markers and the different bedrock terrane ages of southern Greenland (Archean versus varying Proterozoic ages). Specifically, streams will be sampled for suspended load sediment from the geologic terranes of southern Greenland. Suspended load sediment will be measured for trace-element and Sr-Nd-Pb isotope composition, and magnetic properties of the sediment will be determined. These data will be compared with previously made and new measurements on a core off of southern Greenland from a well-studied sediment sequence spanning the last 430 kyrs and 5 interglacials. Isotope studies on piston core samples will focus on the silt size fraction in order to minimize the influence of far traveled clay size sediment. Ice rafted sediment will also be avoided. Trace element records combined with previous and newly obtained magnetic records will provide estimates of the response time of the southern GIS to a warming climate by identifying the timing and duration of ice sheet retreat. The Sr-Nd-Pb isotope tracers will allow calculations of sediment sources and when ice retreated off portions of southern Greenland, thus estimating its contribution to higher sea levels. In particular, the disappearance of relatively young Proterozoic sediment at the core site places the southern GIS margin behind its current location. A subsequent reduction in Archean sediment and dominance of intermediate age Proterozoic sediment places the southern GIS margin in central Greenland.

该奖项根据 2009 年美国复苏和再投资法案（公法 111-5）提供资金。卡尔森 0902571 威斯康星大学？麦迪逊 GIS 行为的古重建中一个重要的缺失部分是缺乏明确的冰盖示踪剂。建议使用陆源标记和格陵兰岛南部的不同基岩地体年龄（太古宙与不同的元古代年龄）来开发这种用于格陵兰冰盖（GIS）退缩和空中范围的示踪剂。具体来说，将从格陵兰岛南部地质地体的溪流中采集悬浮沉积物样本。将测量悬浮负载沉积物的微量元素和 Sr-Nd-Pb 同位素组成，并确定沉积物的磁性。这些数据将与之前对格陵兰岛南部附近岩心进行的测量和新测量进行比较，这些测量来自经过充分研究的沉积物序列，横跨最后 430 公里和 5 个间冰期。对活塞核心样品的同位素研究将集中于淤泥尺寸部分，以尽量减少远距离粘土尺寸沉积物的影响。冰筏沉积物也将被避免。微量元素记录与之前和新获得的磁记录相结合，将通过确定冰盖退缩的时间和持续时间来估计南部地理信息系统对气候变暖的响应时间。 Sr-Nd-Pb同位素示踪剂将允许计算沉积物来源以及冰从格陵兰岛南部部分地区消退的时间，从而估计其对海平面上升的贡献。特别是，核心地点相对年轻的元古代沉积物的消失使 GIS 南部边缘落后于当前位置。随后太古代沉积物的减少和中元古界沉积物的主导地位使地理信息系统南部边缘位于格陵兰岛中部。