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

西罗斯海湾的全新世冰川消退：来自东南极出口冰川的限制

• 批准号: 1542756
• 负责人: Michelle Koutnik
• 金额: $ 33.52万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-08-01 至 2022-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1542756&HistoricalAwards=false
• 关键词: Holocene; Deglaciation; Western; Ross; Embayment

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.

重建过去南极冰盖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做出现实预测所需的数值模型都很重要。模型估计，罗斯海部门是南极洲海平面上升的最大贡献者之一，因为冰盖在过去一万年中从冰期到全新世进行了调整。在这一部分，流入海湾的冰流来自南极西部的冰流和南极东部流经跨南极山脉的出口冰川。观测数据限制了末次盛冰期和全新世退缩，但模型是必要的，以了解出口冰川达到观测到的高位所需的环境条件，以适应观测到的退缩模式，并了解南极洲西部和东部冰的贡献如何随时间变化。调查人员将利用现有的地质和地球物理数据，流动模型和逆模型，以调查的四个跨南极出口冰川的演变有足够的数据存在。这个新的建模的目标是约束这些冰川在末次冰期的冰川，薄在全新世，并达到他们现在的状态所需的冰川条件。通过测试特定的假设，这项工作有助于跨学科的努力，了解全新世冰川消退的罗斯海湾。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早期职业调查员的支持。

项目成果

Holocene thinning of Darwin and Hatherton glaciers, Antarctica, and implications for grounding-line retreat in the Ross Sea

南极洲达尔文和哈瑟顿冰川全新世变薄以及对罗斯海接地线退缩的影响

• DOI: 10.5194/tc-15-3329-2021
• 发表时间: 2021
• 期刊: The Cryosphere
• 作者: Hillebrand, Trevor R.;Stone, John O.;Koutnik, Michelle;King, Courtney;Conway, Howard;Hall, Brenda;Nichols, Keir;Goehring, Brent;Gillespie, Mette K.
• 通讯作者: Gillespie, Mette K.

The contrasting response of outlet glaciers to interior and ocean forcing

出口冰川对内部和海洋强迫的对比响应

• DOI: 10.5194/tc-14-2515-2020
• 发表时间: 2020
• 期刊: The Cryosphere
• 作者: Christian, John Erich;Robel, Alexander A.;Proistosescu, Cristian;Roe, Gerard;Koutnik, Michelle;Christianson, Knut
• 通讯作者: Christianson, Knut