Full-waveform tomography of the northeastern Tibetan Plateau based on the quadratic Wasserstein-metric
This study collected waveform data from 50 regional seismic events recorded by 114 broadband seismic stations located at the northeastern margin of the Tibetan Plateau.Utilizing the full-waveform inversion method based on the quadratic Wasserstein(W2)metric and operating within the 10～100 s frequency band,we obtained high-resolution crust-mantle structural images for the region.Our findings indicate that the mid-lower crust of the Qinling orogenic belt exhibits high-velocity characteristics,suggesting that the plateau's deep crustal weak material has not infiltrated this area.However,the deep crust spanning from the Songpan-Garze Block across the Kunlun Fault to the Qinling-Qilian Block presents low S-wave velocity,positive radial anisotropy(VSH＞Vsv),and an anomalous high Poisson's ratio,hinting at the horizontal flow of deep crustal materials.In contrast,the central part of the Qinling-Qilian Block exhibits deep crustal high-velocity features accompanied by negative radial anisotropy(VSH＜VSV)and a low Poisson's ratio anomaly,implying a cessation of crustal flow in this location.Furthermore,the Longriba Fault presents as a distinct structural anomaly boundary within the deep lithosphere,suggesting it might delineate the leading edge where the Yangtze Block is wedging westward into the Tibetan Plateau.
Northeastern Tibetan PlateauWasserstein metricWaveform inversionCrustal flowRadial anisotropyPoisson's ratio
万方数据
维普
