Vertical profiles of shear wave velocity anomalies. Profiles A–A′ and B–B′ are along latitude 30°N and 28.5°N. Profiles C–C′, D–D′ and E–E′ are along longitude 86°E, 87°E and 88.5°E. Locations of these profiles are shown in Figs 13 and 14. The velocity anomalies are calculated relative to the average shear wave velocity in southern Tibet. Topography and Moho are plotted above and in the velocity anomaly profiles. The main geological boundaries and the N–S trending rifts are marked with the abbreviations as same as in Fig. 1.