Interaction between mass changes of the Antarctic Ice Sheet and solid Earth in Dronning Maud Land, East Antarctica

南极洲东部多宁莫德地南极冰盖与固体地球质量变化之间的相互作用

• 批准号: 404719077
• 负责人: Dr.-Ing. Mirko Scheinert
• 金额: --
• 依托单位: Sektion Paläoklimadynamik
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2023-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/404719077?language=en
• 关键词: Interaction; between; mass; changes; Antarctic

This project aims to determine the deformation of the Earth’s crust in the Atlantic sector of East Antarctica, by geodetic GNSS measurements with improved spatial resolution and over a long time span of partly more than 20 years. The response of the solid Earth to present and past ice-mass changes shall be estimated, namely the instantaneous elastic response and the glacial-isostatic adjustment. The renewal proposal is based on an updated plan to carry out repeated GNSS measurements in western and central Dronning Maud Land (DML) as well as in the region of Molodeshnaya, Enderby Land. Glacial-isostatic adjustment (GIA) still exerts the greatest uncertainty when determining the mass balance of the Antarctic Ice Sheet by satellite gravimetry. The only direct measurement of the GIA effect can be obtained by realizing geodetic GNSS measurements on bedrock. As investigated so far, the vertical deformation pattern is not uniform across Antarctica. DML and, at least to a certain extent, Enderby Land are areas where comparably small deformation signals are expected but measured so far by only a few geodetic GNSS sites. The group of the applicant initiated campaign-style geodetic GNSS measurements in DML in 1995, and in Enderby Land in 2007. Most of these sites are situated in the mountain ranges that run parallel to the coast about 100 to 200 km inland as well as in coastal areas like Schirmacher Oasis and Oasis Molodeshny. Given the long time span of 15 years and more, it is timely to repeat the geodetic GNSS measurements. We expect to determine the vertical deformation rate with an accuracy of down to a few mm/a. For this, we aim to investigate in detail the effect of temporal and spatial correlations on the adjusted deformation rates and associated uncertainties when using the differential GNSS processing. Subsequently, the GNSS-inferred vertical deformation rates will serve as constraints for an improved GIA determination. The GIA effect will be estimated in two ways: First, satellite altimetry and gravimetry will be combined to empirically estimate ice-mass balance and GIA. Second, by close cooperation with partners from AWI, the 3D rheological structure of the Earth will be revised and, subsequently, introduced into GIA predictions. Special attention will be given to improve consistency in applying rheological parameters in the calculation of both the instantaneous elastic deformation and GIA. Thus, we aim to contribute to the currently ongoing discussion within the scientific community on how the physical processes in the Earth’s interior can be captured in a better way, to learn about their complexity, and to gain an improved understanding of the interaction between ice-mass changes and solid Earth that is reflected by GIA and related sea-level change.

该项目旨在通过提高空间分辨率的大地测量 GNSS 测量，在部分超过 20 年的较长时间跨度内，确定东南极洲大西洋区地壳的变形。应估计固体地球对当前和过去冰块变化的响应，即瞬时弹性响应和冰川均衡调整。更新提案基于一项更新计划，旨在在 Dronning Maud Land (DML) 西部和中部以及 Enderby Land 的 Molodeshnaya 地区进行重复 GNSS 测量。在通过卫星重力测定南极冰盖的质量平衡时，冰川均衡调整（GIA）仍然具有最大的不确定性。 GIA 效应的唯一直接测量可以通过在基岩上实现大地测量 GNSS 测量来获得。根据迄今为止的研究，整个南极洲的垂直变形模式并不均匀。 DML 和恩德比地（至少在一定程度上）预计会出现相对较小的变形信号，但迄今为止只有少数大地测量 GNSS 站点进行了测量。申请人小组于 1995 年在 DML 和 2007 年在 Enderby Land 启动了活动式大地测量 GNSS 测量。这些地点大多数位于内陆与海岸平行约 100 至 200 公里的山脉以及 Schirmacher Oasis 和 Oasis Molodeshny 等沿海地区。鉴于时间跨度长达15年甚至更长，重复进行GNSS大地测量是及时的。我们期望以低至几毫米/年的精度确定垂直变形率。为此，我们的目标是详细研究使用差分 GNSS 处理时时间和空间相关性对调整变形率和相关不确定性的影响。随后，GNSS 推断的垂直变形率将作为改进 GIA 确定的约束。 GIA 效应将通过两种方式进行估计：首先，将结合卫星测高和重力测量来凭经验估计冰块平衡和 GIA。其次，通过与 AWI 合作伙伴的密切合作，地球的 3D 流变结构将被修改，并随后被引入 GIA 预测中。将特别注意提高瞬时弹性变形和 GIA 计算中应用流变参数的一致性。因此，我们的目标是为科学界目前正在进行的关于如何以更好的方式捕捉地球内部物理过程的讨论做出贡献，了解其复杂性，并更好地了解 GIA 和相关海平面变化所反映的冰块变化与固体地球之间的相互作用。