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

该奖项支持一项为期两年的计划，该计划旨在重建南极半岛南设得兰群岛最后一次冰川高峰期(LGM)的冰范围、海拔和厚度。利文斯顿岛的一个野外季节将涉及绘制冰川漂移的面积范围和地貌，并确定切线的海拔和分布。此外，冰流方向将通过绘制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南设得兰群岛是否存在适合于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沉积物底部保存的植物、藻类和真菌遗骸的碳-14年龄，以及在凸起的海滩沉积物中可能发现的海贝壳、海豹皮和其他有机物质来确定。另一个目标将是集中研究2-3个关键地区的相对海平面曲线，以显示是否有可能在南设得兰群岛建造这类曲线。这项工作将对南设得兰群岛末次冰盛期的冰范围、海拔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。它还将有助于制作一份退冰期年表，这将为控制南半球这一地区冰川消退的机制提供重要线索。

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.