Holocene Deglaciation of the Western Ross Embayment: Constraints from East Antarctic Outlet Glaciers

对过去南极冰盖厚度和范围变化的重建对于评估过去和现在的海平面变化，以及验证对未来气候和海洋条件下的变化作出现实预测所必需的数值模式是很重要的。模型估计罗斯海部分是造成南极海平面上升的最大因素之一，因为在过去的一万年中，冰盖从冰川期调整到全新世。在这一区域，流入海湾的冰流来自南极西部的冰流和流经南极横贯山脉的南极东部的出口冰川。观测资料限制了末次盛冰期和全新世退缩，但要了解出口冰川达到观测到的高架所需的环境条件、拟合观测到的退缩模式，以及了解西南极洲和东南极洲冰的贡献如何随时间变化，模式是必要的。研究人员将利用现有的地质和地球物理数据，结合冰流正演模型和逆演模型，研究有足够数据的四个跨南极出口冰川的演变。这个新模型的目标是限制这些冰川在末次冰期变厚，在全新世变薄，并达到它们现在的状态所必需的冰川学条件。通过测试特定的假设，这项工作有助于跨学科的努力来理解罗斯海海湾的全新世冰川消融。此外，建模将解决可用数据的解析能力，以回答每个目标冰川的关键问题。更广泛的影响包括指导研究生，公共宣传，将研究纳入高中和大学课程，以及支持早期职业研究者。

Reconstructions of past changes in thickness and extent of the Antarctic ice sheet are important for evaluating past and present sea-level change, and for validating numerical models necessary to make realistic predictions of changes under future climate and ocean conditions. Models estimate that the Ross Sea sector was one of the largest contributors to sea-level rise from Antarctica as the ice sheet adjusted during the past ten thousand years from the glacial period to the Holocene. In this sector, ice flow into the embayment comes through West Antarctic ice streams and through East Antarctic outlet glaciers that flow through the Transantarctic Mountains. Observational data constrain the last glacial maximum and the Holocene retreat, but models are necessary to understand the environmental conditions needed for outlet glaciers to reach observed high stands, to fit the observed patterns of retreat, and to understand how the contribution of ice from West Antarctica and from East Antarctica changed over time.The investigators will use available geological and geophysical data in combination with forward ice-flow models and inverse models to investigate the evolution of the four Transantarctic outlet glaciers where sufficient data exist. The objectives of this new modeling are to constrain the glaciological conditions necessary for these glaciers to thicken during the last glacial, thin during the Holocene, and reach their present-day state. By testing specific hypotheses this work contributes to an interdisciplinary effort to understand Holocene deglaciation of the Ross Sea Embayment. In addition, the modeling will address the resolving power of the available data to answer key questions for each target glacier. Broader impacts include mentoring a graduate student, public outreach, incorporation of research into high-school and university classes, and support of an early-career investigator.