The southern margin of the South Tian Shan has drawn attention due to the intense compressional deformation and seismic activity associated with its thrust structures. However, the deformation and seismic activity in the thick-skinned thrust sheets of the root zones are minimal. The Mw 7.1 Wushi earthquake on 23 January 2024 serves as a window to reveal these unknown aspects of the seismic mechanisms in this structural setting. Using the Leveraging Interferometric Synthetic Aperture Radar (InSAR) technique, we unlock critical insights into the coseismic deformation fields. The seismogenic fault is an unmapped segment within the Maidan Fault system, exhibiting a strike ranging from 241° to 222°. It is characterized by a shallow dip angle of 62° and a deeper dip angle of 56°. Remarkably, the seismic rupture did not propagate to the Earth’s surface. The majority of slip distribution is concentrated within a range of 4 to 26 km along the strike, indicating that this earthquake was a thrust event on a blind fault within the thick-skinned tectonics of the South Tian Shan. Coulomb stress changes indicate that aftershocks primarily occur in the stress-loading region. Interestingly, some aftershocks are very shallow, causing clear surface deformation. Inversion results show that the fault planes of two aftershocks are located above the main shock fault plane at extremely shallow depths (<6 km). Combining geophysical profile data, we infer that ruptures in the deep-seated thick-skinned structures during the main shock triggered ruptures in the shallow thrust structures. This triggering relationship highlights the potential for combined ruptures of the main shocks and aftershocks in the deep-seated thick-skinned structures beneath the South Tian Shan to result in larger disasters than typical seismic events.

On October 17th, 2016, a Ms6.2 earthquake occurred in Zaduo County of Qinghai Province, China. The aim of this study is to use synthetic aperture radar (SAR) technology aboard the Sentinel-1A satellite to obtain high-resolution co-seismic surface displacement data and then to confirm the geometric parameters of the fault and slip distribution model. To this end, linear and non-linear inversion algorithms based on an elastic half-space dislocation model were used. The results showed that a distributed slip model can explain the surface deformation field measured by InSAR very well. The surface deformation field caused by the earthquake was an oval-shaped region of subsidence with a maximum displacement of 5 cm along the line of sight of the radar waves. This earthquake was mainly the result of a normal-slip fault process with 72°N strike and 65° dip. The slip was mainly concentrated at depths of 9–15 km. The maximum slip was 0.17 m, located at a depth of 12 km. The moment magnitude given by inversion was Mw5.9. This was basically in agreement with the moment magnitudes and surface magnitudes measured by USGS and CENC

Due to hard observation condition of the western Tibet region, the slip behaviors of the Ms7.1 Karakoram Pass earthquake occurred in Hetian, Xinjiang on November 19, 1996 remains unclear. Using ERS 1/2 SAR data and InSAR technique, we obtain the co-seismic deformation of the earthquake. The north and south deformation areas show asymmetric pattern, with the maximum LOS displacement of the southern part approximately 24.6 cm, and the maximum LOS displacement in the northern part approximately − 18.5 cm. Nonlinear and linear inversion algorithms are used to determine the geometric parameters and slip distribution of the earthquake fault. Our results show that the co-seismic displacement is dominated by deformation fields are clearly visible sinistral strike-slip accompanied by a small amount of normal slip component. The co-seismic slip occurred between 0 and 18 km at depth. The maximum slip is ~ 81 cm, occurring at a depth of 8.5 ± 0.5 km at (35.36°N 78.03°E), indicating a shallow event with a moment magnitude of Mw 6.5. The seismogenic fault is a secondary fault in the Karakoram fault zone with strike 96°, dip 84°, and rake – 24°. This earthquake shows that the Karakoram fault zone undergoes a complex tectonic deformation process, with central part of the fault zone showing minor tensional deformation behaviors.

Precise earthquake locations and InSAR (Interferometric Synthetic Aperture Radar) deformation observation are the major methods to understand the earthquake occurrence and disaster-causing process. This paper proposes a processing framework for analyzing strong earthquake mechanisms from one-dimensional velocity inversion to precise earthquake locations combined with InSAR deformation observation, and discusses earthquake-generating fault and dynamic mechanisms of tectonic deformation. We analyzed the Menyuan Ms 6.9 earthquake in 2022 and discuss the historical seismic activities and corresponding stress adjustment processes in the research region. To analyze and study the seismogenic structure and mechanism of the earthquake, we investigated the spatial and temporal distribution characteristics of the Menyuan earthquake sequence and analyzed the InSAR coseismic deformation field. We obtained the precise locations of the main shock and aftershocks and the coseismic InSAR deformation field of the main shock. It was confirmed that the Ms 6.9 earthquake was a shallow sinistral strike-slip earthquake, which led to the sequential activation of the Tuolaishan and Lenglongling faults. The main seismogenic fault of the mainshock was the northwestern end of the Lenglongling fault, and the earthquake rupture was segmented. It can be inferred that the earthquake was a stress-adjusted event triggered in the Qilian-Haiyuan tectonic belt caused by the northeasterly push of the Qinghai-Tibet Plateau. The risk of moderate to high earthquakes in the region remains high in the future, requiring enhanced seismic observations.