Whole-mantle body-wave tomography under the hotspot of La Réunion

留尼汪岛热点下的全地幔体波断层扫描

• 批准号: 247995824
• 负责人: Professor Dr. Heiner Igel
• 金额: --
• 依托单位: Sektion Geophysik
• 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/247995824?language=en
• 关键词: Whole; mantle; body; wave; tomography

The island of La Reunion is one of the most active and long-Iived volcanoes in the world. Its time- progressive, 5500-km long hotspot track emerges from the Deccan Traps of India, one of the largest flood basalt provinces on earth, which had a massive impact on global climate and life when they erupted. We want to establish the heat source and "plumbing system" that has been fueling this powerful hotspot for 65 million years. Through the RHUM-RUM project, a German- French effort funded mainly by the DFG and the ANR, we have deployed more than 90 broadband, ocean-bottom and Sand seismometers across the western Indian Ocean since 2011.The goal of RHUM-RUM is to seismically image a mantle plume - or lack of plume - from the surface down to the core-mantle boundary, and to understand the results in terms of material and heat flow. This comprises vertically ascending flow in the plume conduit, as well as any lateral flow spreading into the upper mantle of the western Indian Ocean. Here we are asking for funding for a Ph.D. Student to work the acquired waveform data into three-dimensional, whole-mantle P- and S-wave models of the mantle. We will be using multi-frequency tomography, a state-of-the art waveform Inversion method. Technical novelties or near-novelties include(i) the fully finite-frequency processing and Inversion of ocean-bottom and island seismograms across the entire usable frequency range of body waves.(ii) embedding of the RHUM-RUM data into a hemisphere-scale, whole-mantle model by joint Inversion with all other broadband data available for the hemisphere.(iii) the inclusion of core-diffracted waves, thanks to fully numerical waveform modeling. The goal is a significant improvement in structure of the lowermost mantle, the presumed footing region of deep mantle plumes.

La Reunion岛是世界上最活跃，最长期的火山之一。它的时间进步，5500公里长的热点轨道来自印度的Deccan陷阱，这是地球上最大的洪水玄武岩省之一，当它们爆发时，对全球气候和生活产生了巨大影响。我们想建立一直在为这一强大的热点加油的热源和“管道系统”已有6500万年了。通过Rhum-Rum项目，主要由DFG和ANR资助的德国法国努力，我们已经在印度洋西部部署了90多个宽带，海洋底和砂地震仪。rhum-Rum的目的是在地震羽毛上形象形象形象，或者从表面上不缺乏羽毛 - 从表面上到核心 - 核心 - 核心 - 了解核心的热量，并了解成果，并以实质性的效果，并以实质性的效果来实现。这包括羽流导管中的垂直上升流以及任何侧向流入印度洋西部的上地幔。在这里，我们要求获得博士学位的资金。学生将获得的波形数据用于地幔的三维，全壳P-和S波模型。我们将使用多频断层扫描，这是一种最先进的波形反演方法。技术新颖性或近乎病情包括（i）在整个可用频率范围内的海洋底和岛层的完全有限的频率处理和反转。（ii）将rhum-rum数据嵌入到半球尺度上，全面的逆向模型中，与所有其他宽带数据完全播放，所有宽带数据可用于ii to-ii to-ii ii ii ii ii ii ii ii ii ii ii ii ii ii ii ii ii ii ii ii ii ii ii ii ii ii。数值波形建模。目的是在最低地幔的结构上有显着改善，这是深lum羽的假定基础区域。