The Vertical-component Teleseismic P-wave Receiver Function Studies And Its Application

Teleseismic P waveforms contain lots of informations related to P-S phase andmultiples （PmsPms、PmpPms and PpPmp et al.） which caused by the interfaces ofthe crust and upper mantle. It is very useful to study the velocity structure below thestation, because these phase carried most information of the internal structure of theEarth. The receiver function method has been wildly used in different region or globalcrust and upper mantle velocity structure, and achieved great scientific results.Northeast margin of Tibetan Plateau, which has been long impacted by theIndian continent and Eurasian continent, is a key research area to study the Tibet. Inthis paper, we extracted the Moho multiple phase（PpPmp）from the deep-teleseismicwaveform data of Lanzhou seismic array and temporary seismic array in theSouth-East region of Gansu province. Finally, We get the crust structure belowLanzhou seismic array and the temporary seismic array in the South-East region ofGansu province with vertical-component teleseismic P-wave receiver function.The main results of our study are as follows. The average Crystalline Basementbelow Lanzhou seismic array is about7km, and the average crust thickness is51.6±1.8km. Crystalline Basement and Moho fluctuation below the South-East Gansutemporary seismic array is very intensity because of the collision between Eurasiancontinent and Indian continent. The average Crystalline Basement is about7.6km.The average thickness of the Moho is about46.5km, which is deeper in the west andsouthwest region, while shallower in the eastern and centralregion. There isantisymmetric relationship between Crystalline Basement and Moho fluctuation inSouth-East Gansu. It is also obvious antisymmetric relationship between CrystallineBasement and Moho fluctuation in the area where strong earthquakes have occurred.The depression of Crystalline Basement and uplift of Moho are formed in theintersection of the faults zone. The medium-strong earthquakes are distributed in thesharp-change-belt or edge of Crystalline Basement and Moho, it is related to thesharp-change-belt and transitional zone where the crustal stress is easy toaccumulate.