The analysis of crustal deformation patterns in the Tashkent region, Uzbekistan, derived from GNSS data over the period 2018–2023

Abstract

The Tashkent region is one of the most tectonically and seismically active areas in Uzbekistan. Although it is highly significant, the understanding and quantification of current deformation processes are still incomplete, especially concerning space-based geodetic techniques like the Global Navigation Satellite System (GNSS). Using velocity field data from 16 permanent GNSS sites during 2018–2023, this paper analyzes the strain rate field and its spatial characteristics using an improved least squares collocation method. The results indicate a northeastward motion consistent with India-Eurasian convergence, with velocities ranging from 24.7 to 30.1 mm/yr and increasing from northwest to southeast. The region displays substantial positive dilation at a rate of 14.7 nanostrain/yr, while the neighboring areas demonstrate negative dilation ranging from −10 to −30 nanostrain/yr. The second strain rate invariant with an average value of 20 nanostrain/yr primarily occurs along the Karzhantau fault. The spatial features of strain rate fields delineate the extensional and compressional strain zones, bounded in the west by the Tien Shan orogenic belt. Therefore, these zones warrant increased attention due to their relatively higher seismic risk in the Tashkent region.