Mapping the upper mantle structure beneath the South Atlantic and the adjacent continents using full waveform tomography with geodynamic interpretations of hotspot flux and material transport in the asthenosphere.

使用全波形断层扫描绘制南大西洋和邻近大陆下方的上地幔结构图，并对软流圈中的热点通量和物质传输进行地球动力学解释。

基本信息

批准号：
172686521
负责人：
Professor Dr. Hans-Peter Bunge, Ph.D.
金额：
--
依托单位：
Eidgenössische Technische Hochschule Zürich (ETH)
依托单位国家：
德国
项目类别：
Priority Programmes
财政年份：
2010
资助国家：
德国
起止时间：
2009-12-31 至 2015-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/172686521?language=en
关键词：
Mapping upper mantle structure beneath

项目摘要

We propose to combine full waveform tomography and geodynamic forward modelling to address key questions concerning the geodynamics and evolution of the South Atlantic region: (1) How and to which extent does the South Atlantic plume system feed the asthenosphere in the oceanic basin and adjacent regions? (2) What are the current thermal states of the Walvis Ridge and the Etendeka and Paraná continental flood basalt? (3) What, if any, is the pathway of slow seismic material from the upper to the lower mantle? (4) Is the prominent topographic gradient across the South Atlantic region from Africa to South America explicable solely in terms of lower mantle structure, or do we also find a systematic gradient in upper mantle heterogeneity across the ocean basin? (5) What is the relation of upper mantle heterogeneity and anisotropic structure to the Mid-Atlantic ridge system and hotspots? The use of full waveform tomography will allow us to exploit as much information as possible from seismograms. Our approach is thus well suited for regions with comparatively low data coverage such as the South Atlantic. Mineral physics models will allow us to infer dynamically important constraints on lateral temperature variations in a thermodynamically self-consistent way from the seismic observations. Observations of seismic anisotropy and geodynamic modelling will help us to further quantify and substantiate our inferences on the thermal state and material flux in the South Atlantic upper mantle.

我们建议将全波形层析成像和地球动力学正演模型结合起来，以解决有关南大西洋地区地球动力学和演化的关键问题：（1）南大西洋羽流系统如何以及在多大程度上为大洋盆地和邻近地区的软流圈提供食物(2) 沃尔维斯海岭以及埃滕德卡和巴拉那大陆溢流玄武岩当前的热状态是什么？ (3) 慢震物质从上部到下部的路径是什么（如果有）？ (4) 从非洲到南美洲的南大西洋地区显着的地形梯度是否只能用下地幔结构来解释，或者我们是否也发现整个洋盆的上地幔异质性存在系统梯度？上地幔异质性和各向异性结构与大西洋中脊系统和热点的关系是什么？全波形断层扫描的使用将使我们能够从地震图中利用尽可能多的信息。因此，非常适合数据覆盖率相对较低的地区，例如南大西洋。矿物物理模型将使我们能够从地震各向异性和地球动力学观测中以热力学自洽的方式动态推断出横向温度变化的重要约束。建模将帮助我们进一步量化和证实我们对南大西洋上地幔热状态和物质通量的推论。