Chronology of the West Antarctic Ice Sheet: New Evidence from Marie Byrd Land Nunataks

0087709 Kurz该奖项支持一个详细的基于实验室的研究项目，该项目对在Mt.南极洲西部玛丽伯德地执行委员会山脉的一座冰原岛峰。 对这些样本的初步工作导致了对西南极洲内陆过去冰盖海拔的测量。 这里需要资金来测量冰碛和邻近火山岩床剩余样品的暴露年龄。 其目标是使用现场观测，表面暴露测年（氦-3，氖-21和氯-36）和氩-40/氩-39测年的组合，以限制西南极冰盖（WAIS）过去的海拔。 最初的研究表明，冰碛物记录了过去较高的冰水平，冰碛物由冰消退留下的火山碎屑组成，氦-3和氯-36表面暴露年代测定可用于限制过去冰高的时间。 预计这些分析将完善有关最后一次冰川消退的初步结果，并提供一个独特的早期冰盖海拔记录。 主要的长期目标是提供10 kA之前WAIS内部古冰川学的年代学和高程数据。 这一独特的地表冰海拔记录。Waesche提供了冰盖行为及其对气候和海平面变化的反应的关键限制。 这些信息将有助于确定为什么WAIS在上一次冰消期和前一次间冰期表现得如此，并将有助于预测它在未来将如何变化。

0087709Kurz This award supports a project for a detailed laboratory-based study of glacial moraine boulders collected on the flank of Mt. Waesche, a nunatak in the Executive Committee Range, Marie Byrd Land, West Antarctica. Preliminary work on these samples resulted in measurement of past ice sheet elevations in interior West Antarctica. Funds are requested here to measure exposure ages in the remaining samples from the moraine and adjacent volcanic bedrock. The goal is to use a combination of field observations, surface exposure dating (Helium-3, Neon-21 and Chlorine-36) and Argon-40/Argon-39 dating to constrain past elevations of the West Antarctic ice sheet (WAIS). The initial study demonstrated that higher past ice levels are recorded by moraines, composed of volcanic debris left behind by receding ice, and that Helium-3 and Chlorine-36 surface exposure dating can be used to constrain the timing of past ice high stands. It is expected that these analyses will refine the initial results pertaining to the last deglaciation and provide a unique record of earlier ice sheet elevations. The primary long-term objective is to provide chronological and elevation data of the paleoglaciology of the interior of the WAIS prior to 10 kA. The unique record of surface ice elevations at Mt. Waesche provides key constraints on the behavior of the ice sheet and its response to climate and sea level change. This information will contribute strongly to determining why the WAIS behaved as it did during the last deglaciation and the previous interglacial, and will help efforts to predict how it will change in the future.