The precise analysis of the activity faults and crustal deformation patterns on the Northeastern corner of the Tibetan Plateau is crucial for understanding regional large earthquakes and seismic hazard analysis.Combined with the pre-existing GPS velocity field,we obtained the GPS velocity field with higher spatial resolution in the study area by establishing encrypted observation of three cross-fault profiles composed of 21 continuous GPS stations.We analyzed the spatial clustering characteristics of GPS velocity field by using the combination of K-means clustering and Euler vector.It is found that there are significant differential deformations inside the Longxi block.Combined with the existing block-fault division model,we proposed an advanced block-fault model which is more consistent with the latest GPS velocity field.The major feature of the advanced model is the presence of a NE-trend right-lateral shear zone within the Longxi block.By utilizing the latest GPS velocity field and the advanced block-fault model,we utilized the back-slip dislocation model to infer the motion characteristics of the main blocks and slip rates of the primary faults.The results show that the right-lateral shear zone in the advanced block-fault model plays an important role in allocating strain accumulation characteristics in the region.Consequently,the calculated contraction rate of the Liupanshan fault is notably lower than previous results,suggesting a corresponding reduction in seismic hazard.
维普
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