Preliminary analysis of teleseismic receiver functions of the Ningxia and its adjacent area

The teleseismic receiver functions of digital seismic network of Ningxia and its adjacent area are calculated with two different Gauss filter factors. The accuracy and stability of the receiver functions are discussed. The h-k stacking method is applied to estimate the crustal thickness and velocity ratio beneath seismic stations. The results indicate that there are sharp changes of crustal thickness and velocity ratio in the studied region. This region is located in the northeastern margin of Tibet, and also a junction of several first-grade blocks. The large contrast of crustal structure in this region is considered to be resulted from the interaction of these blocks. Our results are helpful to construct the completed model of the formation and evolution of the Tibet. Some local structures are also discussed combining with the geological faults.