Geodynamic modelling and tomographic visibility of a mantle plume under La Réunion

留尼汪岛地幔柱的地球动力学建模和层析可见性

基本信息

批准号：
247034637
负责人：
Professor Dr. Heiner Igel
金额：
--
依托单位：
Sektion 2.5: Geodynamische Modellierung
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2014
资助国家：
德国
起止时间：
2013-12-31 至 2018-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/247034637?language=en
关键词：
Geodynamic modelling tomographic visibility mantle

项目摘要

The goal of the German-French experiment RHUM-RUM is to seismologically image a mantle plume - or its absence - under the hotspot of La Réunion, and to understand the results in terms of convective flow at all depth levels of the Earth mantle. Most of the ocean-bottom and island data will become available in late 2013.The work we propose here consists of two kinds of interrelated, a priori modeling studies, meant to accompany the data analysis components of RHUM-RUM. In Work Package 1 (one Ph.D. student) we propose to develop a new geodynamic model of the Réunion mantle plume interacting with large-scale flow, which is commonly considered to be largely driven by subducted slabs, but possibly also by active upwellings under Africa and the Indian Ocean. In Work Package 2 (one Ph.D. student), we will investigate the tomographic observability of such a priori reasonable plume structures.We propose a full-fledged parameter and uncertainty study a priori (Down to which threshold of each rheological / physical parameter should a plume still be detectable, at each depth?), rather than the very topical resolution tests that are typically shown a posteriori in order to justify a preferred model obtained from the real data. Our geodynamic models, and their expected tomographic signatures, can therefore be regarded as a true predictions. As observations become available from the RHUM-RUM data analyses by colleagues, the models will be compared to them, geodynamical parameters will be narrowed down, and modified models will be run. Both work packages contain strong components of computational method development, in terms of mantle convection simulations and broadband waveform inversion.Our overarching objectives are:1. Better geodynamical models in general, of the process of a hypothesized classical plume rising from a Large Low Shear wave Velocity Province (LLSVP) - a generation mechanism currently thought to apply to most oceanic hotspots. 2. A clear and comprehensive understanding of which structures, if present, could or could not be resolved by the actual RHUM-RUM data.3. An immediate geodynamical context for actually observed structures, once they become available, i.e., at a moment when the project experiences its maximum momentum and greatest interest from the scientific community.

德国法国实验的目的Rhum -Rum的目的是在LaRéunion的热点下在地震中形象地幔李子或它的缺失，并在地面所有深度水平的对流流量方面了解结果。大多数海底数据和岛屿数据将于2013年底提供。我们在这里提出的工作包括两种相互关联的先验建模研究，旨在适应Rhum-Rum的数据分析组件。在工作包1（一位博士学位的学生）中，我们建议开发一种与大规模流相互作用的新的地球动力学模型，该模型与大规模流相互作用，这通常被认为主要是由俯冲板驱动的，但也可能由非洲和印度大洋洲下的非洲积极上升上升。在工作包2（一位博士学位的学生）中，我们将调查对这种先验的合理李子结构的层析成像观察。我们提出了一个成熟的参数和不确定性研究（下降到每个流变学 /物理参数的阈值，羽毛的阈值在每个深度都可以在每个深度上都可以在每个典型的典型的典范中均可检测到典型的典范，而不是典型的典型序列。数据。因此，我们的地球动力学模型及其预期的层析成像特征可以被视为真正的预测。随着同事的Rhum-Rum数据分析可获得的观察结果，将将模型与它们进行比较，将缩小地球动力学参数，并将运行修改的模型。在地幔施工模拟和宽带波形倒置方面，这两个工作包都包含计算方法开发的强大组成部分。我们的总体目标是：1。一般而言，更好的地球动力学模型是从大型低剪力波速度省（LLSVP）上升的假设经典羽流的过程 - 当前被认为适用于大多数海洋热点的一代机制。 2。清楚而全面的了解，如果存在，则可以或无法通过实际的rhum-rum数据来解决哪种结构。3。实际观察到的结构的直接地球动力学背景，一旦它们可用，即在项目经历其最大动力和科学界最大的兴趣的那一刻。