大陆地壳作为直接被地质构造活动产生和改造的结果，忠实地记录了这些构造演化过程。确定中国大陆现今的地壳结构，对于研究大陆板块演化特性、大陆动力学和地震灾害机理有着重大的科学意义。通过统计分析已发表的利用接收函数方法估计中国大陆的地壳厚度结果，我们发现在构造活动地区同一个地震台站不同研究者得到的地壳厚度差异很大，有的甚至达到10km以上。本项目拟通过加入P波在Moho面的反射震相PmP走时数据来降低因复杂地壳结构造成的接收函数方法对地壳厚度的不确定性，并发展一种新的联合接收函数和PmP走时的叠加方法来同时确定台站下方的地壳厚度、Vp/Vs波速比和Vp，并把它用在中国大陆所有固定和流动宽频地震台站1-2年的波形数据上，从而得到新的更精确的覆盖中国大陆的地壳厚度、Vp/Vs波速比和Vp变化模型。本申请项目希望成为组建“中国区域地震学参考模型”的基金项目之一。

Continental crust,a direct product of geological processes and tectonic modification, has recorded the tectonic history on Earth. Determination of crustal structure of mainland China has important scientific and practical significances for studying continental plate evolution and dynamics as well as understanding earthquake hazards. By statistically analyzing published crustal thickness results of mainland China based on receiver function data so far, we found that in some tectonically active regions in China, crustal thicknesses beneath the same station from different groups could differ by more than 10 km. We plan to add PmP travel times to receiver function data in order to reduce crustal thickness estimate uncertainty caused by complex crustal structure. We will first try to extract PmP travel times from teleseismic S waves through deconvolution and/or from auto-correlation of ambient noise. We will then develop a new stacking method to combine teleseismic P-wave receiver functions and PmP travel times to determine crustal thickness, Vp/Vs ratio, and Vp beneath each available broadband station in mainland China and to map their lateral variations. We hope that the project could be funded as part of the group effort to construct “The China Geophysical Reference Model”initiated by NNSFC.