Mapping the thickness of crust and lithosphere of South America

岩石圈板块的厚度是板块构造研究中最重要的参数之一。然而，用体波对岩石圈进行的高分辨率地震观测仍然很少，这可能是由于岩石圈-软流圈边界（LAB）的梯度性质，或者是由于LAB作为低速带（软流圈）上边界的广角观测所带来的问题。最近发展起来的S接收函数法似乎提供了一个理想的手段来观察LAB。在过去的十年中，德国（SFB 267）和美国在安第斯山脉进行了一些临时地震实验，并收集了大量的数据。在这里，我们建议应用S接收函数方法，这些数据和分布在整个南美洲大陆的永久站，以测量岩石圈的厚度在南美洲。这项技术虽然还是新的，但已被证明对绘制夏威夷和冰岛羽流轨迹以及大陆碰撞区天山和帕米尔的LAB非常有用。对整个岩石圈结构的了解，而不仅仅是地壳，将大大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.