Abstract: The Northeastern margin of the Tibetan Plateau is under ongoing uplifting, whose tectonic structures have always been a research hotspot. Previous studies of surface wave tomography in this region show significant differences, which may be related to different tomography methods. We performed Rayleigh wave phase velocity tomography using both ray-theory and Eikonalequation methods in this study. We compared the tomography results of 20 s, 30 s and 60 s obtained from the two methods which showed relatively consistent velocity features. The overall velocity characteristics are consistent with the distribution of main structural units in the study area. The Northeastern of the Tibetan Plateau shows a low velocity anomaly, while the Ordos Block shows a high velocity anomaly. In the Yinchuan-Hetao Graben, Eikonal-equation based tomography shows more obvious low velocity anomalies in 20 s and 30 s, and the distribution of low velocity anomalies is better consistent with the contour of the graben, indicating that the Eikonal-equation based tomography can make use of the data more sufficiently.

Key words: Northeastern Tibetan Plateau, lithospheric structure, surface w ave tomography, rayleigh wave phase v elocity