Information-variation constrained seismic tomography for enhanced geological modeling of the southeastern margin of the Tibetan Plateau

The southeastern margin of the Tibetan Plateau, situated at the tectonic intersection of the oblique collision between the Indian and Eurasian plates, exhibits prominent features of crustal shortening, lateral block extrusion, and partial melting associated with Cenozoic intracontinental deformation. It constitutes a key area for studying the formation and evolution of the Tethys tectonic belt, providing crucial constraints on the uplift and growth of the plateau. Although there are many seismic velocity models with variable resolutions for the region, the effective integration between seismic velocity models and geological interpretations remains limited, hindering a more complete understanding of lithospheric structure and tectonic evolution. To address this issue, we developed a new body-wave travel time tomography method constrained by the variation of information, which enhances the correlation among different velocity properties. By applying this method to the southeastern margin of the Tibetan Plateau, we obtained intrinsically consistent Vp, Vs, and Vp/Vs models with a lateral resolution of 0.2°. Compared with previous studies, our results exhibit significantly improved correlation between Vp and Vp/Vs models. To further interpret the velocity models, we applied the feature-weighted clustering algorithm to identify physically coherent domains. Based on the clustering results, we can divide the lithosphere of the region into distinct geological domains, which is helpful for constructing the tectonic framework of the southeastern Tibetan Plateau. Overall, this new tomography method, combined with the clustering analysis, establishes a geological modeling framework that can bridge the gap between seismic velocity models and geological models.