Abstract: We have inverted Rayleigh wave dispersion measurements to image the group velocity structure of the lithosphere under the northeastern China to a depth of about 100 km, using waveform data recorded by 122 broadband stations of Heilongjiang, Jilin, Liaoning and Inner Mongolia digital seismic networks. Rayleigh wave group velocities at periods of 8~25 s and 25~70 s were measured from ambient noise cross-correlation and surface wave, respectively. At the short periods of 8~15 s, group velocities are notably correlated with the surface geology and controlled apparently by the large faults dividing basins and ranges. Beneath Songliao Basin, the significant low velocity suggests there is relatively thick sediment. Compared with the group velocities of 8~25 s periods,velocities at periods of 20~30 s change drastically, which reveal that Moho depths in the western regions of North-South gravity lineament (NSGL) are deeper than that in the eastern regions. At the long periods of 50~70 s, with the increase of the periods, the low-velocity in the eastern regions move westward; meanwhile, the western regions show stable high-velocity features. The results may suggest asthenospheric upwelling under the eastern regions of NSGL which may be affected by the subduction of Pacific slab.

Key words: Ambient noise, Surface wave, Tomography, Lithosphere velocity structure, Northeastern China