Lithosphere and Ice Sheet dynamics of West Antarctica

西南极裂谷系（WARS）是地球上最大的大陆裂谷之一，它承载着西南极冰盖（WAIS），目前正处于快速退缩和质量损失的状态。正如一些研究人员预测的那样，WAIS的完全崩溃将导致全球海平面上升3到5米。然而，对未来WAIS行为的预测具有很高的不确定性，因为人们对它过去的演变，特别是对全球气候变化和长期构造过程的反应知之甚少。即将到来的Polarstern远征PS 104计划于2017年初进行，为收集和调查很少访问的西南极洲阿蒙森海部分的样本提供了难得的机会。这个地区经历了整个南极洲最大的冰川损失。这次探险还首次提供了从阿蒙森海获得钻探沉积物的可能性，这些沉积物记录了WAIS过去的前进和后退。对于这个项目计划，我们的目标是解决以下主题和问题：（一）构造的先决条件和对冰川作用的潜在影响：什么时候西南极洲地形需要大陆冰川作用的演变，以及在哪里和什么时候裂谷分支的WARS形式，这可能是温暖的海水的路径，其特点可能是热流升高？(ii)长期冰川演变：WAIS是何时开始的，它如何应对先前的全球变暖和变冷？(iii)现代冰川构造的建立：继LGM之后，如何以及何时实现了当前的构造？冰川退缩是一个持续的过程，还是一个偶发的过程，与全球全新世气候和海平面变化相一致？我们将解决这些问题，通过应用组合的热年代学定年方法，同位素分析，岩相学分析，和表面暴露定年基岩，碎屑沉积物从岩芯中检索，和冰川erratics。该项目的结果将有助于更好地了解过去的WAIS行为及其控制因素，这反过来又将为预测未来的WAIS行为及其对人类社会的影响提供基准。该项目计划涉及SPP 1158的两个叠加主题，即大陆的发展和气候系统组成部分的动力学。

The West Antarctic Rift System (WARS) is one of the largest continental rifts on earth, and it hosts the West Antarctic Ice Sheet (WAIS), which is currently in a state of rapid retreat and mass loss. A complete WAIS collapse, as predicted by some researchers, would result in a global sea level rise of three to five m. Predictions for future WAIS behaviour, however, are associated with high uncertainties, because its past evolution, particularly in response to global climate change and long-term tectonic processes, are poorly understood. The upcoming Polarstern expedition PS 104, scheduled for early 2017, offers the rare opportunity for collecting and investigating samples from the seldom visited Amundsen Sea sector of West Antarctica. This area experiences the highest glacial losses of whole Antarctica. The expedition also offers, for the very first time, the possibility of obtaining drilled sedimentary deposits from the Amundsen Sea, which record past advances and retreats of the WAIS. For this project plan, we aim to address the following topics and questions; (i) tectonic prerequisites and potential influences on glaciation: when did West Antarctic topography required for continental glaciation evolved, and where and when did rift branches of the WARS form, which may serve as pathways for warm ocean water and which may be characterized by elevated heat flow? (ii) Long-term glacial evolution: when was the WAIS initiated and how did it respond to previous periods of global warming and cooling? (iii) Establishment of modern glacial configurations: Following the LGM, how and when were current configurations achieved? Was glacial retreat a continuous process, or rather episodic, in concert with global Holocene climate and sea level variations? We will tackle these questions by applying a combination of thermochronological dating methods, isotope analysis, petrographic analysis, and surface exposure dating to bedrock, clastic deposits retrieved from the drill cores, and glacial erratics. The results of this project will contribute to an improved understanding of past WAIS behaviour and its controlling factors, which in turn will provide benchmarks for predicting the future WAIS behaviour and its impact on human society. The project plan refers to two of the superimposed topics of SPP 1158, namely to Development of the continent and to Dynamics of climate systems components.