Collaborative Research: Fluctuations of the West Antarctic Ice Sheet in Relation to Lake History in Taylor Valley, Antarctica, Since the Last Glacial Maximum

0540073普伦蒂斯该奖项支持一个项目，以检查近地表沉积物在泰勒谷，南极洲的地层。泰勒谷下游的表层沉积物有两种截然不同的假说，这两种假说对南极西部冰盖（WAIS）如何响应末次冰消期海平面上升和全新世环境变化具有重要而又截然不同的意义。有一种假说认为，这些沉积物被命名为罗斯I号漂流物，直接反映了冰消期海平面上升期间罗斯海WAIS收缩的10，000年（14C年），可能是由冰消期海平面上升驱动的。另一种假说认为，泰勒沉积物对冰消期WAIS变化的影响不大。 这两种假说反映了对沉积物记录的根本不同的解释。在两个实地调查季节和第三年在国内机构的过程中，该项目将使用冰川地质学、地球化学、100 MHz和400 MHz的探地雷达以及便携式沉积物取芯来检验这两种假设。拟议的工作的智力价值是，它将测试这两个假设，并使新的地下记录，可能会导致新的见解WAIS敏感性在冰川消退。这项研究还将直接测试沃什伯恩冰川湖在末次冰期最大期（LGM）期间比以前提出的要大得多的结论。如果这一事件是真实的，那么它代表了一种令人震惊的气候异常。这些当地的冰盖和湖泊问题的答案直接涉及到更大规模的问题，海平面上升，气候变化和内部冰盖动态的影响，自末次冰期以来的WAIS衰退。对这个项目有许多更广泛的影响。 了解麦克默多海峡地区的冰川和湖泊历史对WAIS在未来海平面和全球气候变化中的作用具有重要意义。此外，泰勒谷的历史对LTER小组目前正在进行的生态系统研究具有重要意义。最后，在拟议的研究过程中，该项目将培养两名研究生和本科生，该研究将突出学生的教学。

0540073PrenticeThis award supports a project to examine the stratigraphy of near-surface sediments in Taylor Valley, Antarctica. Two contrasting hypotheses have been proposed for surface sediments in lower Taylor Valley, which have important and very different implications for how the West Antarctic Ice Sheet (WAIS) responded to the sea-level rise of the last deglaciation and Holocene environmental changes. One hypothesis holds that the sediments, designated Ross I drift, directly reflect 10,000 14C-years of WAIS shrinkage in the Ross Sea during and perhaps driven by deglacial sea-level rise. The other hypothesis, holds that the Taylor sediments have little significance for WAIS change during the deglaciation. These two hypotheses reflect fundamentally different interpretations of the sediment record. Over the course of two field seasons and a third year at the home institutions, the project will test these two hypotheses using glacial geology, geochemistry, ground penetrating radar (GPR) at both 100 MHz and 400 MHz, and portable sediment coring. The intellectual merit of the proposed work is that it will test these two hypotheses and make novel use of the subsurface record that may result in new insights into WAIS sensitivity during the deglaciation. The study will also directly test the conclusion that Glacial Lake Washburn was much larger than previously proposed during the Last Glacial Maximum (LGM). This occurrence, if real, represents a stunning climate anomaly. Answers to these local ice sheet and lake questions directly pertain to larger scale issues concerning the influences of sea-level rise, climate change, and internal ice-sheet dynamics on the recession of the WAIS since the LGM. There are numerous broader impacts to this project. Understanding the glacial and lake history in the McMurdo Sound region has important implications for the role that the WAIS will play in future sea-level and global climate change. Moreover, the history of Taylor Valley has significance for the ecosystem studies currently being conducted by the LTER group. Lastly, during the course of the proposed research, the project will train two graduate and undergraduate students and the research will be featured prominently in the teaching of students.