AMS Radiocarbon Chronology of Glacier Fluctuations in the South Shetland Islands During the Last Glacial/Interglacial Hemicycle:Implications for Global Climate Change

AMS 末次冰期/间冰期半旋回期间南设得兰群岛冰川波动的放射性碳年表：对全球气候变化的影响

• 批准号: 9814349
• 负责人: Brenda Hall
• 金额: $ 9.74万
• 依托单位: University of Maine
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-01-01 至 2003-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9814349&HistoricalAwards=false
• 关键词: AMS; Radiocarbon; Chronology; Glacier; Fluctuations

This award supports a two year program to produce a new reconstruction of ice extent, elevation and thickness at the Last Glacial Maximum (LGM) for the South Shetland Islands in the Antarctic Peninsula. One field season on Livingston Island will involve mapping the areal extent and geomorphology of glacial drift and determining the elevation and distribution of trimlines. In addition, ice flow direction will be determined by mapping and measuring the elevation of erosional features and the position of erratic boulders. One of the main goals of this work will be to demonstrate whether or not organic material suitable for radiocarbon dating exists in the South Shetland Islands. If so, the age of the deposits will be determined by measuring the carbon-14 age of plant, algal, and fungal remains preserved at the base of the deposits, as well as incorporated marine shells, seal skin and other organic material that may be found in raised beach deposits. Another goal will be to concentrate on the development of relative sea-level curves from 2-3 key areas to show whether or not construction of such curves for the South Shetland Islands is possible. The new reconstruction of ice extent, elevation and thickness at the Last Glacial Maximum for the South Shetland Islands which will be produced by this work will be useful in studies of ocean circulation and ice dynamics in the vicinity of the Drake Passage. It will also contribute to the production of a deglacial chronology which will afford important clues about the mechanisms controlling ice retreat in this region of the southern hemisphere.

该奖项支持了一个为期两年的项目，该项目将对南极半岛南设得兰群岛末次冰川极大期（LGM）的冰范围、海拔和厚度进行新的重建。在利文斯顿岛的一个实地季节将包括绘制冰川漂移的面积范围和地貌，并确定等边线的高度和分布。此外，冰流方向将通过测绘和测量侵蚀特征的高程和不规则巨石的位置来确定。这项工作的主要目标之一将是证明在南设得兰群岛是否存在适合放射性碳测年的有机物质。如果是这样的话，沉积物的年龄将通过测量保存在沉积物底部的植物、藻类和真菌遗骸的碳14年龄来确定，以及合并的海洋贝壳、海豹皮和其他可能在凸起的海滩沉积物中发现的有机物质。另一个目标将集中于开发来自2-3个关键区域的相对海平面曲线，以表明是否有可能为南设得兰群岛建造这样的曲线。这项工作将对南设得兰群岛末次冰期冰的范围、高度和厚度进行新的重建，这将有助于研究德雷克海峡附近的海洋环流和冰动力学。它还将有助于产生一个去冰期年表，这将为控制南半球这一地区冰退缩的机制提供重要线索。