远震接收函数方法及其在海域岛礁区地壳结构研究中的应用

Teleseismic Receiver Function Method and Its Application to the Crustal Structure Study of Oceanic Reef and Islands

远震接收函数方法从远震P波波形中提取出台站下方主要速度间断面的信息,是研究地壳、上地幔结构的有效方法。该方法通过拟合转换波波形来约束间断面深度和横波速度。传统的接收函数线性反演方法强烈依赖于初始模型的选取,其反演结果存在较大的不确定性,为此新的基于非线性的反演方法逐渐发展起来,另外,接收函数与面波联合反演以及S波接收函数方法的提出也在一定程度上降低了反演结果的非唯一性。接收函数方法在大陆区地壳结构的研究中得到了广泛运用,但对于海区和岛礁区的研究却非常缺乏,本文回顾了国内外一些岛礁区的接收函数研究实例,介绍了西沙群岛琛航岛的天然地震观测及其结果,探讨了接收函数方法在岛礁区地壳结构研究中的应用前景。

Teleseismic receiver function,which extracts information about the main velocity interfaces beneath seismic station from the teleseismic P waveforms,is proved to be an efficient method to study the crust and upper mantle structures.This method constrains the depth and S velocity of the main velocity interfaces by fitting the converted S waveforms.In order to overcome the limitation that linear inversion method depends on the initial model,some non -linear inversion methods are employed in receiver function method.Furthermore,the joint inversions of receiver function and surface wave as well as the S receiver function method have also reduced the non-uniqueness to some extent.Receiver function method has been generally used to study continent structures,but seldom in oceanic reef and islands.This article reviewed some cases of receiver function studies in this type of area at domestic and abroad.Firstly,the paper introduced the seismological observations at Chenhang on Xisha Islands,Then,the paper discussed the prospect of the receiver function application to reef and islands.