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

重建南极冰盖过去的厚度和范围的变化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需的数值模型是重要的。模型估计，罗斯海部分是南极洲海平面上升的最大贡献者之一，因为在过去一万年里，从冰期到全新世，冰盖发生了调整。在这一地区，流入海湾的冰流通过西南极冰流和流经横贯南极山脉的东南极出口冰川。观测数据限制了最后一次冰川高峰期和全新世的消退，但为了了解出口冰川到达观测高位所需的环境条件，为了符合观测到的消退模式，以及理解来自南极洲西部和南极洲东部的冰的贡献如何随着时间的推移而变化，模型是必要的。研究人员将使用现有的地质和地球物理数据，结合正向冰流模型和反向模型来研究四个有足够数据的横跨南极的出口冰川的演化。这个新模型的目标是限制这些冰川在最后一次冰期变厚、在全新世变薄以及达到现在的状态所需的冰川条件。通过检验特定的假设，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，建模将解决现有数据的分辨率，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堂，以及对职业生涯早期调查人员的支持。

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.