Abstract: We selected waveform data from 223 teleseismic events recorded by Heilongjiang, Jilin, Liaoning, Inner Mongolia regional permanent networks and NECESSArray temporary network, obtained 22569 P-wave relative travel-times by multi-channel cross correlation measurement, calculated travel-time sensitivity kernels, and applied the finite-frequency tomography to determine three-dimensional P-wave velocity structure model of the mantle down to the depth of 600 km beneath Northeast China. We evaluated the resolution of inversion results by using checkerboard test. Our results reveal a low-velocity anomaly extending from 80 to at least 200 km depth beneath the Songliao basin, which corresponds to the characteristics of high temperature and low density in this depth range, so this low-velocity anomaly may imply partial melting of the upper mantle. The velocity structures on the both sides of the North-South Gravity Lineament (NSGL) are obviously different, and this difference can extend below 200km depth, which is suggest that NSGL may be a variation belt or a boundary of internal structures in the upper mantle beneath Northeast China. There is a wide range of low-velocity anomalies beneath the Changbaishan volcanic region, which can extend from the shallow part of the upper mantle to the mantle transition zone. We speculate that these low-velocity anomalies may reflect the upwelling of hot materials in the mantle transition zone, and the upwelling is mainly caused by the subduction of the Pacific plate.

Key words: Finite-frequency tomography, Velocity structure of the upper mantle, Songliao basin, North-South Gravity Lineament, Changbaishan volcano