Coseismic Deformation and Slip Distribution of the 2024 Mw 7.0 Wushi, Xinjiang, Earthquake from High-Rate GNSS

Abstract On 23 January 2024, at 02:09:05 a.m. Beijing time, a magnitude Mw 7.0 earthquake struck Wushi County in Aksu Prefecture, Xinjiang. This study utilized high-frequency (1 Hz) observation data from six Global Navigation Satellite System (GNSS) stations near the epicenter to investigate its coseismic deformation. The data were processed using Pride PPP-AR 3.0 software, revealing maximum coseismic displacements (east: 10.3 mm, north: 55.7 mm, and up: −5.5 mm) represent component-specific extremes observed across the network, with each maximum originating from distinct stations. To extract more precise coseismic signals, we decomposed the high-rate GNSS time series using the complete ensemble empirical mode decomposition with adaptive noise method, and combined wavelet threshold denoising and multiscale permutation entropy (MPE) techniques to effectively remove static offsets, nonlinear trends, and low-frequency noise from the original time series. The resulting reconstruction significantly improved the precision and accuracy of coseismic deformation extraction, demonstrating that this approach presents a novel methodology for high-rate GNSS seismic analysis. Using the 1 Hz GNSS coseismic displacements as constraints, we applied the particle swarm optimization algorithm with the Okada model to invert fault geometry parameters. The results indicate that the fault responsible for the Wushi earthquake has a strike of 238°, a dip of 53°, and a rake of 20°. We further integrated the inverted fault geometry with GNSS observed surface deformation data to perform a distributed fault-slip inversion using the steepest descent method. The inversion results show that the coseismic rupture was confined to depths of less than 23 km, with no surface rupture observed. The maximum slip of 1.1 m occurred at a depth of 11 km, ∼18 km northeast of the mainshock. The energy released is consistent with a moment magnitude of Mw 7.0, corroborating findings from seismological analyses.