Mechanisms for uplift and deformation of the Tibetan Plateau remain vigorously debated; hypotheses include stepwise growth, distributed thickening, and crustal channel flow, each with a distinct anisotropic signature. We have developed a new azimuthally anisotropic shear velocity model for the lithosphere beneath eastern Tibet, based on ambient noise tomography from 643 seismic stations. In our model, the Tibetan upper crust is characterized by strong anisotropy with fast axes that correlate with surface geology and mantle anisotropy, suggesting the occurrence of coherent deformation. However, a much different picture emerges in the middle and lower crust, where anisotropy is disordered and weaker beneath the plateau than along its margins, inconsistent with the prediction of large‐scale eastward crust flow in eastern Tibet. Our observations are best explained by heterogeneous crustal thickening beneath the plateau with complex flow in the middle and lower crust, accompanied by asthenospheric upwelling along the southeastern plateau margin.

Significance: The Songpan-Ganzi terrane lies in the central-east of the Tibetan Plateau, which was considered a stable block in some tectonic models. Its deformation mode is of crucial importance for understanding the evolutionary history and seismic hazard of the plateau. The recent Maduo earthquake occurred inside the terrane. We resolve a bilateral rupture process with distinct super- and subshear rupture modes for this event. We also find that pervasive folding structures that are aligned by shear deformation in the current Songpan-Ganzi terrane are responsible for the seismic wave anisotropy and shear strain orientation in its upper crust. Its deformation mode can be classified as distributed simple shear, which receives shear loads from side walls and produces internal earthquakes.

Uplifting mechanisms for the Tien Shan, an active intracontinental orogenic belt, have been under debate for decades, a key issue being how the convergence has been accommodated at depth. Here we investigate the Moho structure across the Central Tien Shan by common‐conversion‐point imaging and H‐k‐c stacking of receiver functions from a dense array. The observed Moho exhibits distinct characteristics among subblocks. A southward‐dipping diffuse Moho is imaged in the South‐Central Tien Shan (SCTS), in contrast with the relatively flat and sharp Moho beneath the Tarim Basin. This feature along with the large Moho offset beneath the South‐Boundary Fault suggests that the shortening and thickening of the Tien Shan crust rather than the underthrusting of the Tarim Basin are responsible for the uplift of the SCTS. In the North‐Central Tien Shan, however, the imaged Moho doublet provides direct evidence for the underthrusting of the Kazakh Shield accommodating the convergence there.

Syncontractional extension is prominent in present-day Tibet, but its origin remains vigorously debated. Several deep-seated geodynamic processes (e.g., Indian underthrusting, horizontal flow, and mantle upwelling) have been linked to Tibetan rifting. Indian underthrusting is a good candidate because it can well explain why surface rifts are more prominent south of the Bangong–Nujiang suture; however, how Indian underthrusting causes extension is not well understood and lacks observational constraints. Seismic anisotropy, measured by exploiting the birefringence effect of shear waves, can be indicative of the deformation styles within the crust. Here, we unveil the dominant convergence-parallel alignment of anisotropic fabrics in the deep crust of the southern Tibetan rifts using seismic recordings collected from our recently deployed and existing seismic stations. This finding suggests that the strong north-directed shearing exerted by the underthrusting Indian plate is key to enabling present-day extension in southern Tibet.

The mechanisms of surface uplift of Hangai Dome (>2 km) and formation of Cenozoic intraplate volcanism in central Mongolia remain vigorously debated. Here we directly investigate the mantle transition zone (MTZ) structure beneath central Mongolia to explore whether the deep mantle geodynamical processes have played a role. Our results reveal significant MTZ thinning of 8–13 km in three subareas mainly caused by the uplifted 660‐km discontinuity (∼10 km). In addition, the 410‐km discontinuity is depressed beneath the Hangai Dome (∼6 km) and the northern portion of the study area (10–15 km). These observations provide direct evidences for intracontinental mantle upwellings from the lower to the upper mantle, causing the Cenozoic uplift and basaltic volcanism of central Mongolia. Furthermore, these mantle upwellings are relatively sluggish compared to canonical mantle plumes based on the small magnitude of MTZ thinning and thus relatively moderate thermal anomaly within the MTZ (62–100 K).