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

南极冰盖对最近两次冰期/间冰期周期气候变化的敏感性

• 批准号: 0944150
• 负责人: Brenda Hall
• 金额: $ 35.42万
• 依托单位: University of Maine
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-01 至 2014-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0944150&HistoricalAwards=false
• 关键词: Sensitivity; Antarctic; Ice; Sheet; Climate

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.

霍尔/0944150该奖项支持一个项目，该项目旨在调查南极冰盖对过去两次冰川/间冰期周期中全球气候变化的敏感性。该项目的学术价值在于，尽管它对地球气候系统很重要，但我们目前对AIS对全球气候变化的敏感性缺乏充分的了解。该项目将重建罗斯海地区过去两个冰川/间冰期周期内海洋冰的历史并准确地确定其日期，这将使人们能够更好地了解冰波动的潜在驱动机制(即海平面上升、冰动力学、海洋温度变化)。这也将有助于把目前的冰盖行为放在一个长期的背景下。在上一次冰川盛期(LGM)期间，已知AIS填满了罗斯湾，尽管已经在海洋和陆地环境中做了很多工作来限制其范围，但冰盖的年代学，特别是最大冰期的时间和持续时间以及最初的衰退模式，仍然不确定。此外，对倒数第二次冰川运动几乎一无所知，除了推测它与末次冰川运动大体相似外。这些缺陷极大地限制了我们理解AIS演化和冰盖波动背后的驱动机制的能力。该项目将从皇家学会范围内测年良好的冰川地质数据中，不仅为末次冰期，而且为倒数第二次冰川(阶段6)开发一份详细的罗斯湾西部冰川范围和年代学记录。年代学将主要来自高精度加速器质谱仪(AMS)碳-14(14C)和多收集器电感耦合等离子体质谱(MS)234U/230Th测年，这些测年已知在拟议的野外地区广泛存在的湖泊藻类和碳酸盐。这项工作的更广泛影响是，它非常符合西南极冰盖倡议，并补充了ANDRILL计划。此外，督导人员致力于各级学生的教育和外展，并有长期的记录。许多学生(4-6岁)将在这个项目中接受指导。国际和平协会定期访问教室，谈论南极洲，与实地的学生交流，并参与当地的外联工作，以吸引女孩学习地球科学。

项目成果

Ice-sheet expansion from the Ross Sea into McMurdo Sound, Antarctica, during the last two glaciations

• DOI: 10.1016/j.quascirev.2022.107379
• 发表时间: 2022-02
• 期刊: Quaternary Science Reviews
• 影响因子: 4
• 作者: Stephanie L. Heath;B. Hall;G. Denton;G. Henderson;C. Hendy