Mapping the thickness of crust and lithosphere of South America

岩石圈板块厚度是板块构造研究的重要内容之一。然而，用体波对岩石圈进行高分辨率地震观测仍然很少见，这可能是因为岩石圈-软流圈边界(LAB)的梯度性质，或者是与将LAB作为低速带(软流层)上边界进行广角观测有关的问题。最近发展起来的S接收函数方法似乎为观察实验室提供了一种理想的手段。在过去的十年里，德国(SFB267)和美国在安第斯山脉进行了一些临时地震实验，并收集了大量数据。我们建议将S接收函数方法应用于这些数据以及分布在整个南美大陆的永久观测站，以测量南美洲的岩石圈厚度。这项技术虽然仍然是新技术，但已被证明对绘制夏威夷和冰岛羽流轨迹以及横跨天山和帕米尔大陆碰撞带的实验室地图非常有用。了解整个岩石圈的结构，而不仅仅是地壳，将极大地提高我们对南美洲板块构造的理解。

The thickness of the lithospheric plates is one of the most important keys in plate tectonics. Yet high-resolution seismic observations of the lithosphere with body waves is still rare, probably because of the gradient nature of the lithosphere-asthenosphere boundary (the LAB) or problems connected with wide-angle observations of the LAB as an upper boundary of a low-velocity zone (asthenosphere). The recently developed S receiver function method appears to provide an ideal means to observe the LAB. In the last decade a number of German (SFB 267) and US temporary seismic experiments have been operated in the Andes and have collected a large amount of data. We propose here to apply the S receiver function method to these data and to the permanent stations distributed in the entire South American continent to measure the thickness of the lithosphere in South America. This technique, although still new, has proven very useful for mapping the LAB at the Hawaiian and Iceland plume tracks and across the continental collision zone Tien Shan and Pamir. Knowledge about the structure of the entire lithosphere, not only the crust, will significantly improve our understanding of plate tectonics of South America.