Imaging the topography of the Lithosphere-Asthenosphere Boundary beneath South and East Africa using S receiver functions; a key to understand continental lithospheric evolution in and around active rifting systems

这项提议的目的是研究南非和东非地幔岩石圈的结构。这一地球动力学活动区尚不存在岩石圈-软流圈边界(LAB)的高分辨率图像，尽管为了了解全球构造，需要了解岩石圈板块的完整结构，而不仅仅是更容易接触到的地壳结构。这一目标将使用S接收函数的新技术来实现。这项使用S-P转换的技术似乎很有希望探测非洲地震台下的实验室，并已经证明了它在绘制不同构造地区的实验室图方面的能力(见附件)。最近测试的简单求和技术也将被用来确定完整的P和S接收点格林S函数。这项技术将用来限制来自实验室的P和S多次波，从而得到绝对的实验室深度估计。由于从东非和南非的200多个永久和临时宽带站获得的数据，现在可以获得迄今为止前所未有的分辨率的实验室地形图。这些结果可以获得地球动力学过程的详细图像，并显著提高对大陆岩石圈演化以及与大陆裂谷相关的深部地幔过程的认识。

The aim of this proposal is to study the structure of the mantle lithosphere beneath South and East Africa. No high resolution image of the Lithosphere-Asthenosphere Boundary (LAB) exists yet in this geodynamically active region, although for understanding the global tectonics, knowledge of the complete structure of lithospheric plates is required rather than only the easier accessible crustal structure. This goal will be achieved using the novel technique of S receiver function. This technique employing S-to-P conversions appears promising for detecting the LAB beneath seismic stations in Africa and has already proven its power for mapping the LAB in the tectonically different regions (see enclosures). The recently tested plain summation technique will also be used to determine the complete P and S receiver site Green s function. This technique will serve to constrain P and S multiples from the LAB resulting in absolute LAB depth estimation. Due to the available data from more than 200 permanent and temporary broadband stations in East and South Africa, it is now possible to obtain maps of the LAB topography with so far unprecedented resolution. The results may obtain detailed images of geodynamic processes and significantly improve the knowledge of continental lithospheric evolution as well as deeper mantle processes related to the continental rifting.