Determining Middle Miocene through Pliocene Changes in Paleo Ice-flow and Basal Ice Conditions in East Antarctica through Sedimentological Analyses of Core Samples

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。该项目旨在研究从普里兹湾和罗斯海收集的沉积物岩心，以揭示东南极冰盖新近纪的古气候历史。根据目前的测量结果和对全球气温大幅上升的预测，必须调查南极东部冰盖对气候变化的敏感性及其在气候系统中的作用。以前气候变化时期的地质记录为地面实况模型预测提供了机会。该项目的科学目标是确定以前提出的中中新世过渡，从一个更具动态的湿基东南极冰盖到目前的半永久冰盖，部分冻结在其床上。这一转变的时间和意义是有争议的，由于缺乏定量研究，以及过时的冰近端沉积序列。该项目部分填补了这一空白，利用杂岩和砂岩的成分和物理特性，建立冰盖排水通道，古环境和基底冰条件的变化。南极大陆边缘周围两个关键区域的结果将提供对东南极冰盖在中新世中期过渡期以及中新世晚期和上新世已知变暖时期的行为的深入了解。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The project aims on studying sediment cores collected from Prydz Bay and the Ross Sea to unravel the Neogene paleoclimatic history of the East Antarctic ice sheet. In the light of current measurements and predictions of a substantial rise in global temperature, investigations into the sensitivity of the East Antarctic ice sheet to climate change and its role in the climate system are essential. Geological records of former periods of climate change provide an opportunity to ground truth model predictions. The scientific objective of this project is to identify a previously proposed middle Miocene transition from a more dynamic wet-based East Antarctic ice sheet to the present semi-permanent ice sheet that is partially frozen to its bed. The timing and significance of this transition is controversial due to a lack of quantitative studies on well-dated ice-proximal sedimentary sequences. This project partially fills that gap using the composition and physical properties of diamictites and sandstones to establish shifts in ice-sheet drainage pathways, paleoenvironments and basal ice conditions. The results from the two key areas around the Antarctic continental margin will provide insight into the behavior of the East Antarctic ice sheet across the middle Miocene transition and through known times of warming in the late Miocene and Pliocene.