Determination of current geoid trends related to deep Earth processes in the South Atlantic region

确定与南大西洋地区地球深层过程相关的当前大地水准面趋势

• 批准号: 243973216
• 负责人: Professor Dr. Hans-Peter Bunge, Ph.D.
• 金额: --
• 依托单位: Lehrstuhl für Astronomische und Physikalische Geodäsie
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2013
• 资助国家: 德国
• 起止时间: 2012-12-31 至 2015-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/243973216?language=en
• 关键词: Determination; current; geoid; trends; related

We propose to link inferences of vertical motion in the South Atlantic region over a wide range of time scales, from geologic to geodetic, the latter represented by trend analyses of non-tidal, temporal variations in the gravity field derived from ultra-precise GRACE models. The southern part of Africa, in particular, is uniquely suited for this analysis, being a region with some of the most active mantle related dynamic uplift world-wide, with little contamination from hydrologic variability or other processes.The Institute for Astronomical and Physical Geodesy (IAPG) of TU München and the Geophysics Section of Ludwig-Maximilians-University (GS-LMU) are well positioned for this project, as IAPG has been working on satellite concepts for the high resolution modeling of the gravity field for many decades, and GS-LMU has pioneered high resolution global mantle circulation models capable of inferring past mantle flow and structure through sophisticated fluid inverse theory based on the adjoint method.Key questions we wish to address include:1) Can solid Earth related signals be separated in gravity solutions?2) Over which time periods may one rely on a linear interpolation of solid Earth related gravity trends?3) Is there ongoing vertical motion in the region and how does it relate to Cenozoic uplift pulses that have been inferred for the region from geologic observations?The use of the most sophisticated gravity processing techniques, combined with powerful, high resolution mantle circulation to represent non-linear convection signals will help us to distinguish end-member hypotheses on the effect that mantle convection may have in shaping the regional tectonic evolution, namely a dominance of quasi-steady, lower-mantle related flow or, alternatively, a prominence of pulsating, semi-episodic upper mantle flow.

我们建议将南大西洋地区在从地质到大地测量的广泛时间尺度上的垂直运动推论联系起来，后者通过超精确 GRACE 模型得出的重力场非潮汐、时间变化的趋势分析来表示非洲南部特别适合进行这项分析，因为该地区拥有全世界最活跃的地幔相关动态抬升区域，几乎没有受到水文变化或其他过程的污染。天文物理研究所慕尼黑工业大学大地测量学 (IAPG) 和路德维希马克西米利安大学 (GS-LMU) 地球物理学部在该项目中处于有利位置，因为 IAPG 数十年来一直致力于重力场高分辨率建模的卫星概念， GS-LMU 开创了高分辨率全球地幔循环模型，能够通过基于伴随方法的复杂流体反演理论推断过去的地幔流动和结构。我们希望解决的关键问题包括：1) 固体地球相关信号能否在重力解中分离？2) 在哪些时间段内可以依赖固体地球相关重力趋势的线性插值？3) 该区域是否存在持续的垂直运动以及其有何关系到从地质观测中推断出的新生代隆起脉冲？使用最先进的重力处理技术，结合强大的高分辨率地幔环流来表示非线性对流信号，将有助于我们区分关于的效果是地幔对流可能对区域构造演化产生影响，即准稳态、下地幔相关流占主导地位，或者脉动、半幕式上地幔流占主导地位。