Deep Velocity Structure and Tectonic Characteristics of the Pamir Plateau based on Bayesian Inversion

Abstract The Pamir Plateau, at the northwestern margin of the Tibetan Plateau, is a key region for investigating continental collision and plateau uplifting. To probe its deep structure, we collected seismic data from 263 stations across 11 research projects. We applied cross‐correlation to noise data and extracted surface wave dispersion data from cross‐correlation functions. The extracted dispersion data were subsequently inverted using a 3‐D transdimensional Bayesian inversion method (rj‐3DMcMC). The inversion result reveals several crustal low‐velocity zones (LVZs). Their formation is likely related to crustal thickening, the exposure of gneiss domes, and thicker sedimentary sequences compared to surrounding areas. In the lower crust and upper mantle, the LVZs in southern Pamir and southeastern Karakoram evolve into high‐velocity zones, which expand northeastward with increasing depth. This suggests northward underthrusting of the Indian Plate. We also analyzed the Moho using both the standard deviation of S‐wave velocity and the S‐wave velocity structure. Results show that significant variations in velocity standard deviation reliably delineate the Moho interface.