Shear-Wave Velocity Structure of Eastern Margin of Tien Shan from Joint Inversion of Ambient Noise Dispersion and Receiver Functions

Abstract We present the 3D shear-wave velocity structure of the crust and upper mantle beneath the eastern margin of Tien Shan, determined by a joint inversion of ambient noise dispersion data and teleseismic P-wave receiver functions. Waveform data were recorded by 42 uniformly distributed temporary broadband seismic stations and 8 permanent seismic stations between 2019 and 2022. Compared to previous studies, the incorporation of data sets from newly deployed stations provides enhanced structural illumination of the structure of the study region, and the dense seismic array significantly improves model resolution. Short-period surface-wave dispersions, derived from stacked ambient noise cross correlations, and receiver functions from teleseismic records, are used to constrain shallow velocity structure and layered discontinuities. The resulting velocity model is consistent with local geological features, such as basin geometry and Moho depth variations, providing constraints for inferring lithospheric deformation. The velocity model produces synthetic seismograms that show acceptable agreements with observations from the 2 November 2022 Mw 4.5 Xinjiang earthquake, suggesting its potential utility for improving source parameter estimations of local earthquakes in future studies.