Sensitivity of the Antarctic Ice Sheet to Climate Change over the Last Two Glacial/Interglacial Cycles

Hall/0944150该奖项支持一个项目，以调查南极冰盖（AIS）对全球气候变化在过去两个冰期/间冰期周期的敏感性。该项目的智力价值在于，尽管它对地球气候系统很重要，但我们目前缺乏对AIS对全球气候变化敏感性的全面了解。该项目将重建罗斯海部分最近两次冰期/间冰期循环的海洋冰的历史并精确测定其日期，这将有助于更好地了解潜在的驱动机制（即，海平面上升、冰动力学、海洋温度变化）。 这也将有助于放置目前的冰？）在长期的背景下， 在末次盛冰期（LGM）期间，AIS被认为填满了罗斯湾，尽管在海洋和陆地环境中已经做了很多工作来限制其范围，但冰盖的年表，特别是最大的时间和持续时间以及最初衰退的模式，仍然不确定。 此外，对倒数第二次冰期几乎一无所知，除了被认为与LGM大致相似。这些缺点极大地限制了我们理解AIS演变和冰盖波动背后的驱动机制的能力。 该项目将根据皇家学会山脉中年代久远的冰川地质数据，详细记录罗斯湾西部的冰范围和年代学，不仅包括末次冰期，还包括倒数第二次冰期（第6期）。 年表将主要来自高精度加速器质谱（AMS）碳-14（14 C）和多接收器电感耦合等离子体（ICP）-质谱（MS）234铀/230钍测年的湖藻和碳酸盐，已知广泛分布在拟议的领域领域。这项工作的更广泛影响是，它很好地融入了南极西部冰盖倡议，并补充了ANDRILL计划。 此外，PI致力于并在各级学生教育和推广方面有着悠久的记录。一些学生（4-6）将在这个项目中得到指导。PI定期访问教室，谈论南极洲，并与来自该领域的学生交流，并参与当地的外联工作，以吸引女孩学习地球科学。

Hall/0944150 This award supports a project to investigate the sensitivity of the Antarctic ice sheet (AIS) to global climate change over the last two Glacial/Interglacial cycles. The intellectual merit of the project is that despite its importance to Earth's climate system, we currently lack a full understanding of AIS sensitivity to global climate change. This project will reconstruct and precisely date the history of marine-based ice in the Ross Sea sector over the last two glacial/interglacial cycles, which will enable a better understanding of the potential driving mechanisms (i.e., sea-level rise, ice dynamics, ocean temperature variations) for ice fluctuations. This will also help to place present ice?]sheet behavior in a long-term context. During the last glacial maximum (LGM), the AIS is known to have filled the Ross Embayment and although much has been done both in the marine and terrestrial settings to constrain its extent, the chronology of the ice sheet, particularly the timing and duration of the maximum and the pattern of initial recession, remains uncertain. In addition, virtually nothing is known of the penultimate glaciation, other than it is presumed to have been generally similar to the LGM. These shortcomings greatly limit our ability to understand AIS evolution and the driving mechanisms behind ice sheet fluctuations. This project will develop a detailed record of ice extent and chronology in the western Ross Embayment for not only the LGM, but also for the penultimate glaciation (Stage 6), from well-dated glacial geologic data in the Royal Society Range. Chronology will come primarily from high-precision Accelerator Mass Spectrometry (AMS) Carbon-14 (14C) and multi-collector Inductively Coupled Plasma (ICP)-Mass Spectrometry (MS) 234Uranium/230Thorium dating of lake algae and carbonates known to be widespread in the proposed field area. The broader impacts of this work are that it fits well within the West Antarctic Ice Sheet initiative and complements the ANDRILL program. In addition, the PIs are committed to and have a long record of student education and outreach at all levels. A number of students (4-6) will be mentored in this project. The PI regularly visits classrooms to talk about Antarctica and communicates with students from the field and participates in local outreach efforts to attract girls to earth science.