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.

该项目的目的是，通过空间分辨率得到提高的全球导航卫星系统大地测量，在部分超过20年的长时间跨度内确定东南极洲大西洋部分地壳的变形情况。应估计固体地球对现在和过去冰量变化的反应，即瞬时弹性反应和冰川均衡调整。更新建议是基于在德龙宁毛德地西部和中部以及恩德比地Molodeshnaya地区进行重复GNSS测量的最新计划。在利用卫星重力测量确定南极冰盖的物质平衡时，冰川均衡调整（GIA）仍然具有最大的不确定性。对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来获得。根据迄今为止的调查，整个南极洲的垂直形变模式并不一致。DML和恩德比地（至少在一定程度上）是预计会有非常小的变形信号的地区，但迄今为止只有少数几个全球导航卫星系统测地站进行了测量。申请人的小组于1995年在DML和2007年在恩德比地分别启动了北斗式全球导航卫星系统大地测量。这些遗址大多位于与海岸平行的山脉中，内陆约100至200公里，以及Schirmacher绿洲和Oasis Molodeshny等沿海地区。鉴于15年或更长的时间跨度，现在是重复全球导航卫星系统大地测量的时候了。我们期望以低至几mm/a的精度确定垂直形变速率。为此，我们的目标是详细研究时间和空间相关性的影响，调整变形率和相关的不确定性时，使用差分GNSS处理。随后，GNSS推断的垂直变形率将作为改进GIA确定的约束条件。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，以经验方式估计冰质量平衡和GIA。第二，通过与AWI合作伙伴的密切合作，地球的三维流变结构将得到修改，并随后引入GIA预测。将特别注意提高在瞬时弹性变形和GIA计算中应用流变参数的一致性。因此，我们的目标是促进科学界目前正在进行的关于如何更好地捕捉地球内部物理过程的讨论，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和固体地球之间的相互作用。