Constraining paleo-dynamics and sediment transport of Antarctic stream flow across grounding lines - from source to sink

限制南极溪流穿过接地线的古动力学和沉积物输送——从源头到汇

• 批准号: 275409824
• 负责人: Professor Dr. Todd Alan Ehlers
• 金额: --
• 依托单位: Alfred-Wegener-Institut (AWI) Helmholtz-Zentrum für Polar- und Meeresforschung
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 财政年份: 2015
• 资助国家: 德国
• 起止时间: 2014-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/275409824?language=en
• 关键词: Constraining; paleo; dynamics; sediment; transport

This interdisciplinary project integrates high-resolution seismic imaging with numerical models of ice dynamics, erosion, and sediment transport to quantify past and present interactions between glaciers and the solid Earth. In doing this, we test the hypothesis that sub-ice sediment production, transport, and deposition are key controls on past and present day ice dynamics and stability in Antarctica. We will produce a physics based understanding of how ice flow interacts with the solid earth by comprehensivly employing a source-to-sink concept within one of the best geographically constrained glacial catchments, the Ekströmisen in Dronning Maud Land, Antarctica. Within the contemporary discussion of climate change, ice sheet stability, and paleoclimatic conditions, we will contribute to answering the following imminent scientific questions: How did Antarctic drainage basins behave during several glacial cycles? How did grounded ice retreat into the Holocence? What are the governing basal conditions for ice stream flow in drainage basins? To what degree do erosional and depositional processes and underlying strata influence ice dynamics and stability? To address these questions, we will integrate existing seismic data of subglacial strata (e.g. geomorphology and sediment basins) with aero-geophysical information (ice thickness and englacial stratigraphy from radar, geology from gravimetry and magnetics) and satellite remote sensing products (surface elevation and ice-flow velocity). A higher-order numerical ice-flow and subglacial hydrology model will be used to quantify Ekströmisens ice-flow dynamics. Initial conditions (distribution of liquid water, and properties of basal sediment and bedrock) will be derived from radar and seismic data. Ice flow simulations will be coupled with a numerical model for glacial erosion, transport and deposition. These models will quantify the development of Ekströmisens catchment areas geometry, mass transport and basal conditions over multiple glacial-interglacial cycles and enable investigation of possible feedbacks between basal sediment and ice dynamics. Observed sedimentary structure and core records are used to validate the simulated flow behaviour and erosion/sedimentation processes. Taking advantage of the Ekström basins confined geometry, the project will overcome the limitation of previous large-scale sediment source-to-sink studies with multiple source areas and unconfined deposition zones. We will quantify in unprecedented detail ice-dynamic interactions with the underlying strata and the coupling between glacial and solid Earth systems.

这一跨学科项目将高分辨率地震成像与冰动力学、侵蚀和沉积物传输的数值模型相结合，以量化冰川和固体地球之间过去和现在的相互作用。在此过程中，我们验证了以下假设，即冰下沉积物的产生、运输和沉积是控制南极过去和现在冰动态和稳定性的关键因素。我们将通过在南极洲Dronning Maud Land的Ekströmisen冰川集水区内全面采用源到汇的概念，对冰流如何与固体地球相互作用产生基于物理学的理解。在关于气候变化、冰盖稳定性和古气候条件的当代讨论中，我们将有助于回答下列迫在眉睫的科学问题：南极流域在几个冰川周期中的行为如何？搁浅的冰是如何退缩到大屠杀中的？控制流域冰流流动的基本条件是什么？侵蚀和沉积过程以及下伏地层在多大程度上影响冰的动力学和稳定性？为了解决这些问题，我们将把现有的冰下地层地震数据(例如地貌和沉积盆地)与航空地球物理信息(雷达提供的冰层厚度和冰川地层、重力和磁学提供的地质学)和卫星遥感产品(地表高度和冰流速度)结合起来。将使用高阶数值冰流和冰下水文模型来量化Ekströmisens冰流动力学。初始条件(液态水的分布，以及基底沉积物和基岩的性质)将从雷达和地震数据中得出。冰流模拟将与冰川侵蚀、输送和沉积的数值模型相结合。这些模型将量化Ekströmisens集水区在多个冰期-间冰期循环中的几何形状、质量传输和基本条件的发展，并能够调查基础沉积物和冰动力学之间可能的反馈。利用观测到的沉积构造和岩心记录来验证模拟的流动行为和侵蚀/沉积过程。利用Ekström盆地的封闭几何结构，该项目将克服以往大规模泥沙源到汇研究的局限性，即多源区和无限制沉积区。我们将以前所未有的细节量化冰动力与下伏地层的相互作用，以及冰川和固体地球系统之间的耦合。

项目成果

Bathymetry Beneath Ice Shelves of Western Dronning Maud Land, East Antarctica, and Implications on Ice Shelf Stability

• DOI: 10.1029/2019gl086724
• 发表时间: 2020-06-28
• 期刊: GEOPHYSICAL RESEARCH LETTERS
• 影响因子: 5.2
• 作者: Eisermann, Hannes;Eagles, Graeme;Jokat, Wilfried
• 通讯作者: Jokat, Wilfried

Detailed Seismic Bathymetry Beneath Ekström Ice Shelf, Antarctica: Implications for Glacial History and Ice‐Ocean Interaction

南极洲埃克斯特罗姆冰架下详细的地震测深：对冰川历史和冰海相互作用的影响

• DOI: 10.1029/2019gl086187
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: Hattermann;Gaedicke;Berger;Ehlers;T. A. ;Franke;Gromig;Hofstede;Lambrecht;Laeufer;Tiedemann;Wilhelms
• 通讯作者: Wilhelms

Kinematic response of ice-rise divides to changes in ocean and atmosphere forcing

冰升的运动响应划分对海洋和大气强迫变化的影响

• DOI: 10.5194/tc-13-2673-2019
• 发表时间: 2019
• 期刊: The Cryosphere
• 作者: C. Schannwell;R. Drews;T. A. Ehlers;O. Eisen;C. Mayer;F. Gillet Chaulet
• 通讯作者: F. Gillet Chaulet

Quantifying the effect of ocean bed properties on ice sheet geometry over 40 000 years with a full-Stokes model

使用全斯托克斯模型量化 40,000 年来海床特性对冰盖几何形状的影响

• DOI: 10.5194/tc-14-3917-2020
• 期刊: The Cryosphere
• 作者: Schannwell;Ehlers;T. A. ;Malinen
• 通讯作者: Malinen