The Bayesian inversion framework is a powerful framework for solving nonlinear inversion problems, but its application to fault slip inversion is often hindered by high computational costs. In this study, we propose a new approach that approximates the spatial-domain slip distribution using only its low-frequency components in the frequency-domain. This strategy substantially reduces the number of model parameters under the physically reasonable assumption that coseismic slip distributions are smooth and dominated by low-frequency features. We evaluate the method using three synthetic fault slip models with different characteristics, demonstrating that it achieves high data-fitting accuracy with markedly improved computational efficiency. When applied to the 1973 MS7.5 Luhuo (China) earthquake, our approach yields a coseismic slip model that broadly agrees with previous studies in its first-order features, while differences in small-scale details likely reflect variations in the dataset used. This work demonstrates an efficient and robust strategy for Bayesian coseismic slip inversion, enabling broader applications in earthquake source studies.

Abstract The 2025 Mw7.1 Dingri earthquake is the largest normal‐faulting event in southern Tibetan plateau recorded with near‐field observations. By integrating back‐projection imaging, multi‐point‐source inversion, and finite‐fault modeling, we reveal that the rupture propagated at variable speeds in a cascading manner across a complex conjugate fault network, generating significant high‐frequency radiation at the fault junction. Near‐field waveforms directly document the slip along the western boundary of the Dengmecuo graben as coseismic. The spatiotemporal evolution of simultaneous rupture along both boundaries of the graben suggests a possible structural connectivity at depth between two conjugate faults. Mainshock nucleation was likely promoted by sustained stress loading following the 2015 Gorkha earthquake, together with local stress perturbations from recent regional earthquakes and the foreshock sequence. These processes bridge long‐term interseismic deformation and the dramatic seismic rupture of the Dingri earthquake, illustrating a typical slow‐to‐fast failure process.

Widespread subsidence in the North China Plain (NCP) and Shaanxi-Gansu region has been concern of potential hazards. Investigating the underlying factors contributing to this subsidence is essential for effective hazard mitigation policies. In this study, we use GNSS data to derive the vertical velocity difference between the periods of 2011-2014 and 2015-2018. The results feature a general decrease in subsidence rates across the NCP, except in Cangzhou that exhibits a notable increase in subsidence at a rate of 15.4 mm & centerdot;a(-1). In the Shaanxi-Gansu region, subsidence rates are much lower, ranging from-2 to 2 mm & centerdot;a(-1), but Xi ' an stands out with a significant increase of 4.5 mm & centerdot;a(-1). To further explore the mechanism of subsidence, we analyze the vertical GNSS data based on the elastic loading theory to reveal potential corresponding trend changes in terrestrial water (TW). The results indicate that the GNSS-derived TW trend changes in the study area are consistent with statistical and well data, indicating a positive effect on the groundwater level recovery in the NCP due to the central South-to-North Water Diversion (SNWD) project, but the decrease in groundwater level in Xi ' an is probably caused by urban infrastructure activities. This study offers insights for policymakers to address land subsidence and manage water resources.

Investigating the spatial distribution of coseismic rupture, postseismic afterslip, and their interactions is essential for understanding the heterogeneous frictional characteristics of faults, and seismic hazard assessments. This study offers a comprehensive analysis of both seismic and aseismic slip of the 2022 MW6.7 Menyuan earthquake, which took place at the western terminus of the Tianzhu seismic gap located in the northeastern Qinghai-Xizang Plateau. By integrating near-field GNSS measurements, InSAR line-of-sight (LOS) displacements, and surface rupture data, we refined the coseismic slip distribution using a kinematic inversion and a mechanically constrained model. Our results reveal an unexpectedly large coseismic slip of about 3.3 m at shallow depths (less than about 6 km), along with minimal shallow slip deficit—features rarely observed in earthquakes of similar magnitude globally. The mechanically constrained approach yields a static stress drop of about 6.4 MPa. Additionally, we invert for the afterslip distribution from cumulative postseismic GNSS displacements recorded during the initial 2.7 years subsequent to the mainshock. The afterslip is predominantly situated downdip of the coseismic rupture zone, releasing 28.5% of the coseismic moment. There is a tight correlation between the spatiotemporal evolution of aftershocks and the downdip afterslip, with limited contributions from viscoelastic relaxation and poroelastic rebound which indicates that the afterslip mechanism primarily controls early postseismic deformation.

A majorty of the low-lying coastal areas worldwide, where the population is densely concentrated, are confronted with high to extremetly high risks of land subsidence. However, a comprehensive detection and quantification of large-scale coastal subsidence patterns and their primary drivers in eastern China remain lacking. In this study, we employed Time Series Interferometric Synthetic Aperture Radar (TS-InSAR) technique and Sentinel-1 data to derive the vertical deformation pattern at a resolution of 90 m from 2017 to 2024. We developed a novel multi-frame mosaicking method, achieving spatially consistent InSAR observations over the land-sea transition areas. Our findings uncover extensive coastal subsidence in northeastern Shandong and eastern Jiangsu, highlighting several rapid-subsidence funnels with rates exceeding 50 mm/yr for the first time. By integrating Sentinel-2 multispectral imagery, subsidence time series, groundwater level measurements, and principal component analysis (PCA), we further analyzed the spatiotemporal distribution patterns and underlying drivers of these heterogeneous subsidence funnels. Our analysis demonstrates that anthropogenic factors are the dominant drivers of coastal subsidence. Four representative case studies reveal distinct subsidence mechanisms: (1) brine extraction for salt production and aquaculture, (2) excessive freshwater withdrawal for agricultural irrigation and industrial use, (3) groundwater depletion for intensive greenhouse aquaculture, and (4) land reclamation for industrial infrastructure development. In each region, subsidence patterns are predominantly controlled by a single dominant factor. This study is expected to provide valuable insights for monitoring and managing coastal subsidence, enhance our understanding of associated risks, and offer critical guidance for protecting communities in vulnerable coastal areas.

We have developed a 3D viscoelastic finite element model to study processes that control the postseismic deformation due to the 2021 M8.2 Chignik, Alaska earthquake. Our model employs a bi-viscous Burgers rheology to represent the viscoelastic relaxation of the upper mantle and the first two years GPS data after Chignik event as constraints.Initially, we investigated the viscoelastic relaxation mechanism and stress-driven afterslip mechanisms individually. We then attempted to reconcile their contributions by assessing the misfit between observed and simulated displacements. And, it is assumed that the afterslip evolution is governed by rate-strengthening friction. The results show that there exists a substantial misfit between the simulated and the observed value of the optimal model under the viscoelastic relaxation mechanism. Notably, at one observation site in the near-field, the observed displacement exceeds 200 mm, whereas the simulated value only less than 5 mm. Similarly, the optimal solution of simulated value under the afterslip mechanism does not align well with the observed value. Furthermore, we also utilized different frictional properties on updip (0-40 km) and downdip (40-100 km) regions of the coseismic rupture. The preferred misfit in this model is lower than that obtained using the model with a uniform friction parameter, but there is still a discrepancy between the simulated and observed values. These results indicate that neither the afterslip nor viscoelastic relaxation mechanisms alone can fully explain the total postseismic deformation.Subsequently, we utilized an integrated model to simultaneously extract the contributions from both mechanisms. The combined modeling results indicate that the near-field postseismic displacements are dominated by both mechanisms together. However, in the far-field, deformation is primarily controlled by afterslip, with minimal influence from the viscoelastic relaxation mechanism. The inferred frictional properties on the updip and downdip regions of the coseismic rupture exhibit significant differences, which likely reflect variations in fault zone materials at different depths. And the optimal model supports a viscoelastic rheology for the continent mantle, with a steady-state viscosity is 1×1019Pa•s and the transient viscosity is 1×1018Pa•s.

The India-Eurasia collision zone is the largest deforming region on the planet with numerous faults and widespread earthquakes, extending from the Himalayan Front to north of the Tien Shan. Developed from plate tectonic theory, block models have long been used to describe the crustal deformation in the collision zone, and GPS data are often invoked to constrain and test the models. Although previous block models perform well against GPS data on the whole, the detailed performance in many areas of the collision zone remains uncertain due to sparsity of GPS data and the low resolution of the fault database used to define the blocks. In this study, we process the raw GPS data collected via regional continuous GPS observation networks and Crustal Movement Observation Network of China (CMONOC) up to 2021, mainly located in Tibet, and obtain our core GPS velocity field with 420 continuous and 872 campaign stations. We further incorporate published GPS velocities, mainly located in the Himalaya and Tien Shan regions. We convert these velocities into our core solution to keep all the velocities in a consistent reference frame. As a result, we provide the densest and up-to-date GPS velocity field in the India-Eurasia collision zone including 2811 stations. Although the stations from CMONOC have been presented before, our updated velocities are more robust as they are derived from a longer time span, e.g., 5 years more than Wang and Shen [2020]. Also, we add an extra 351 stations for the collision zone compared to Wang and Shen [2020], most of which are continuous stations, over 300 of which have never been published. Wright et al. [2023] presented the first high-resolution InSAR velocity field for whole Tibet. Constraints from the InSAR data enable us to effectively evaluate the detailed performance of block modeling in Tibet, especially in the remote regions where the GPS data are sparse. We incorporate the GPS and InSAR velocity fields, and 170 Quaternary fault slip rates into a recently-developed high-resolution block model with 237 blocks by Styron [2022] to predict block motion and fault slip rates throughout the collision zone. The block model fits the data well in general, although there are some significant residuals. The predicted slip rates along ~900 faults from the model are generally small except for those along several major faults, including the major Tibetan strike-slip faults, which have larger slip rates but still within the level of 10 mm/yr, and the Main Himalayan Thrust, which has a convergence rate at the level of about 15 mm/yr. The predicted slip rates show along-strike variations, and are consistent with previous geodetic studies. We then use our results to assess the limitations of tectonic block modelling for applications in seismic hazard assessment and in understanding the geodynamics of continental tectonics. The results suggest that tectonic strain has two modes: a few major faults exhibit focused strain and high slip rates; between these major structures, deformation is more continuous.

Climatic and anthropogenic changes are reshaping global water resources, with the North China Plain (NCP) experiencing significant surface subsidence due to severe groundwater overexploitation over the past half-century. In this study, we integrate data from Interferometric Synthetic Aperture Radar, Global Navigation Satellite System, and hydraulic head measurements observed in 2015-2019 to investigate aquifers' physical properties and corresponding changes in groundwater storage in NCP. Geodetic measurements indicate seasonal and long-term deformation patterns. The amplitude of seasonal variation of deformation is up to 25 mm with phase lag behind the seasonal variation of water head. The integration of geodetic and hydrological data indicates that local aquifer storativity and clay lens thickness are 0.67x10-3-14.38x10-3 $0.67\times {10}<^>{-3}-14.38\times {10}<^>{-3}$ and 0.15-1.98 $0.15-1.98$ m, respectively. The average long-term subsidence due to sustained water storage loss is about 29 mm/yr, with a peak rate of similar to 120 mm/yr. Even though all regions show a long-term ongoing subsidence, the subsidence trend has slowed in about half of the NCP, which can be attributed to the impact of the South-to-North Water Diversion (SNWD) Project, especially in areas near the SNWD aqueducts. Moreover, we find a disparity in subsidence rates between Hebei and Shandong Provinces, reflecting the impact of different groundwater exploitation management in mitigating the subsidence. This research underscores the effectiveness of combining geodetic and hydrological data for assessing groundwater circulation and optimizing groundwater management.

Although the Lajishan-Jishishan fault zone is considered as one of the most tectonically active orogenic belts along the northeastern margin of the Qinghai-Xizang Plateau, its present-day slip behavior and subsurface geometry remain poorly understood. The 2023 Jishishan earthquake, accompanied by high-resolution geodetic observations, offers a unique opportunity to advance our understanding of the regional tectonism. In this study, both Global Positioning System (GPS) and Interferometric Synthetic Aperture Radar (InSAR) data are used to jointly constrain the coseismic slip distribution associated with the 2023 Jishishan earthquake. Our results suggest that rupture occurred along two distinct fault segments within the Jishishan fault zone: a primary northeast-dipping fault plane and a shallower southwest-dipping subsidiary fault. The inversion results of the double-fault model show a peak slip of 0.40 m on the main fault at a depth of 14.85 km and a peak slip of 0.09 m on the shallow subsidiary fault at 2.35 km depth. This double-fault rupture model is supported by multiple lines of evidence, including geodetic observations, seismological data, and surface fault mapping. The derived coseismic slip model sheds new light on the complex fault structure beneath the Jishi Shan, highlighting the possibility of segmented fault geometries and multi-fault interactions. Specifically, the northeast-dipping fault, identified as the Jishishan West Margin Fault Zone (JSSWF), appears to be intersected at depth by a southwest-dipping structure, likely corresponding to the Jishishan East Margin Fault Zone. This intersection may have disrupted rupture propagation, resulting in a discontinuity along the seismogenic fault plane. Notably, the 2023 rupture was confined to the lower portion of the seismogenic layer, leaving the upper segment of the JSSWF unruptured. This remaining strain accumulation in the shallow crust indicates a potentially persistent seismic hazard in the region.

An M6.2 earthquake struck Jishishan County, Gansu, on December 18, 2023, with its epicenter located in the arc-shaped tectonic belt formed by the Lajishan-Jishishan Fault. Continuous high-rate global navigational satellite system (GNSS) data were utilized to simulate real-time data resolution, enabling the rapid determination of coseismic static and dynamic deformation caused by the earthquake and the estimation of empirical magnitude. Far-field body waves served as constraints for the source rupture process, facilitating the analysis of potential seismogenic fault structures. GNSS stations within 30 km of the epicenter exhibited significant coseismic responses: horizontal peak displacement and velocity reached approximately 6.3 cm and 6.1 cm/s, respectively. Additionally, quasi-real-time differential positioning and post-event precise point positioning results were consistent throughout the source process. Vertical velocity, calculated via epoch-by-epoch differential velocity determination, showed clear coseismic signals, with peak values increasing to 2.6 cm/s. The empirical magnitude, based on displacement, was 5.99, while the magnitude derived from the velocity waveform amplitude was 6.05, both consistent with the moment magnitude. The dynamic displacement distribution preliminarily suggests directional effects of northward rupture propagation, aligning with subsequent aftershock occurrences. Finite fault inversion results, based on the two nodal planes of the focal mechanism, indicate that asperity ruptures concentrated at the hypocenter played a major role. These ruptures propagated from the hypocenter to shallow regions and northward, lasting approximately 10 s. Although the coseismic deformation determined by sparse high-rate GNSS cannot constrain the specific fault dip angle, the relationship between rupture propagation direction from the seismic source model and aftershock distribution suggests a northeast-dipping fault. Moreover, seismic source models representing single faults as geometric structures can only simulate permanent formations. In contrast, the conjugate fault model, which aligns with aftershock distributions, more accurately explains high-rate GNSS displacement waveforms. Considering both regional tectonics and geological survey results, the seismogenic fault is believed to be a local northeast-dipping blind thrust fault. Northward rupture propagation may have caused the movement of conjugate faults. This study is an effective case of using high-rate GNSS for rapid earthquake response, providing a reference basis for understanding the seismic activity patterns and earthquake disaster prevention in the region.

The mechanism that induced the 2019 Changning earthquake sequence is still a subject of debate. The discussion focuses on the dip angle of the seismogenic fault, which is directly associated with the intersection of the fault and the salt well of the Changning salt mine. This study employs Interferometric Synthetic Aperture Radar (InSAR) and Global Positioning System data to analyze the co- and postseismic deformation caused by the 2019 Changning earthquake sequence. The coseismic slip distribution model is constrained by geodetic observations, along with the geometry of the seismogenic faults. The afterslip model is also inverted from InSAR time series approximately one year following the mainshock. The findings indicate that the Mw 5.7 mainshock of the 2019 Changning earthquake sequence ruptured an approximately east–west-trending fault in the Changning anticline, with a dip angle of ∼53°. InSAR observations identified the displacement field resulting from the Mw 5.3 aftershock on 22 June. The majority of the coseismic ruptures took place in regions at depths less than 5 km. The afterslip was primarily observed at depths of 2–4 km, with a peak slip of 0.16 m. The aseismic slip exhibited significant overlap with the coseismic rupture, while minimal seismic and aseismic slip was detected in proximity to the salt wells of the Changning salt mine. According to the geodetic data and previous seismological findings, we propose that the seismogenic fault of the Changning earthquake did not have a direct intersection with the salt wells. Contrasting with the previous established “directly intersected” mechanism, this study introduces a “indirectly intersected” model for the Changning earthquake. This potentially induced mechanism can explain most of the seismological and geodetic observations.

On September 5, 2022, a M6. 8 earthquake occurred in Luding county, Sichuan Province. The epicenter is located at the southeastern end of the Xianshuihe fault. The preliminary results of field geological investigation show that no obvious surface rupture caused in this earthquake. We obtain the static horizontal coseismic displacements within 90 km of the epicenter at 31 survey-mode and continuously operated GNSS stations. The deformation pattern measured by GNSS is agreement with the left-lateral strike slip faulting mechanism. The maximum horizontal coseismic displacement observed by GNSS reaches 23 cm, and the GNSS stations within 50 km of the epicenter records coseismic offsets generally over 1 cm. The optimal coseismic slip model derived from GNSS data shows that the surface rupture mainly concentrated between Moxi town to Tianwan township. The coseismic slip concentrates at depths of 2 similar to 8 km, with the maximum slip of 1. 96 m. The estimated seismic moment is 9. 25 X 10(18) N " m, corresponding to M(w)6. 6. The earthquake has enhanced the Coulomb stress on the fault planes around the periphery of the source rupture area, and a large fraction of aftershocks occurred in the region where Coulomb stress increased. Considering the interseismic coupling ratio, historical earthquake ruptures and Coulomb stress variations, it is worth paying more attentions on seismic hazards of Anninghe fault, Daliangshan fault and Kangding Moxi segment of the Xianshuihe fault in near future.

Impulse motion characterized by a large amplitude in the fault -normal direction can be observed at near -fault strong motion sites during strike -slip earthquakes. The large pulse, which always causes high intensity and stronger damage to structures close to faults, is usually attributed to the directivity effect of rupture propagating along strike and the proximity to the fault. We present an analysis of such a large directivity pulse captured by the near -fault high -rate Global Navigation Satellite System (GNSS) during the 2022 Mw 6.7 Luding, China, earthquake-the largest event ever observed by space geodesy on the seismically active Xianshuihe fault in the eastern Tibetan Plateau. We invert the displacement waveforms and offsets derived from the continuous and campaign GNSS for the rupture kinematics. The inferred slip model reveals a rupture zone of 30 km in length above 15 km depth along the Moxi segment, yielding a seismic moment of 1:1 x 1019 N center dot m and a source duration of 13 s. The high -rate GNSS (hrGNSS) waveforms suggest an asymmetric bilateral rupture: most slips with long rise time are concentrated on the southern part of the ruptured fault, whereas a short -duration pulse -like slip rate with low final slip propagates during the northward rupture. We found that the directivity pulse observed by the nearest hrGNSS site is controlled primarily by the sharp pulse -like slip rate and rapid rupture velocity approximating the local S -wave velocity. Along with additional local amplification, this large directivity pulse may be responsible for the heavy damage in Moxi town close to the northern ruptured fault.

Temporal variations of hydrological mass causes changes in geoid height and surface deformation, resulting in time-variation of orthometric height. The daily Gravity Recovery and Climate Experiment (GRACE) gravity field model and global hydrological models consistent with the temporal resolution of daily Global Position System (GPS) data were employed in this study to estimate the orthometric height variations in mainland China. Based on the spherical harmonic function and Green’s function, the orthometric height variations of 10 major river basins in mainland China showed obvious sub-monthly and annual fluctuations. The annual amplitude of orthometric height variations was distributed according to latitude, and decrease gradually with an increase in latitude. Among the 249 selected GPS stations, >96.8% positively correlated with both daily GRACE and hydrological models derived orthometric height variations, with the GPS stations in the Southwest River Basin having the best correlation. To compare with the daily GPS vertical displacement, it is necessary to consider the surface loading derived from satellite gravity data or hydrological models in relation to their temporal resolution. By removing the surface loading effect from the GPS height, it was observed that the hydrological load was best corrected using the hydrological model instead of GRACE solutions. Finally, we analyzed the vertical tectonic motion of the main tectonic blocks in mainland China by removing the loading derived from the hydrological model and discussed the main influencing factors of tectonic motion.

The January 8th 2022 menyuan earthquake(Mw6.7) occurred along major boundary fault zone in the northeastern Tibetan Plateau.In this study, we derived the co-seismic deformation from pixel offset tracking (POT) and interferometric synthetic aperture radar (InSAR) by using Sentinel-1 data. The inteferograms pattern shows that coseismic deformation is dominated by horizontal movements with the maximum displacement are over 0.5m in both tracks and POT results. Then we inverted the geometry parameters of the causactive fault and the slip distribution of the fault plane based on the finite dislocation model. The result shows the seismogenic fault has an average strike of 108.0 ◦ and a northeast dip angle of 83 ◦ . moreover, the coseismic slip is primarily concentrated on the lenglongling fault with on main asperity of 10 X 23 km and the maximum slip of 3.5m at depth of 4km as well as rupture the eastern of the tuolaishan fault with a small area of 5×5 km at depths of 0–8 km. On the basis of the dCFS results caused by historical earthquakes in tuolaishan fault and geodetic-derived slip rate of the tuolaishan fault, we emphasize the potential seismic risk on western Tianzhu gap is high.

The 20 March 2020 Dingri M(w)5.6 earthquake occurred in the southwestern margin of the Tibetan Plateau, about 250 km away from the 2015 Nepal M(W)7.9 earthquake. Whether the Nepal earthquake, especially the afterslip, triggered the Dingri earthquake remains to be studied. Here, Interferometric Synthetic Aperture Radar (InSAR) and regional seismic data were combined to learn about the rupture features of the Dingri earthquake. We first utilized the near-field displacements together with broadband seismic waveforms to reveal the uniform slip model by using a Bayesian bootstrap optimization nonlinear inversion method. Then, we constructed a fault plane based on the geometrical parameters and inverted the source slip distribution. The study found that the strike of the Dingri earthquake's fault was similar to 334 degrees and the dip was similar to 51 degrees. The rupture range was similar to 5.6 kmx4.4 km, and the total seismic moment released was similar to 3.33x 10(17) N center dot m, corresponding to M(W)5.6. The peak slip was similar to 1.27 m, which occurred at a depth of similar to 3.786 km. The slip was mainly confined between similar to 2.0 and 5.5 km in depth and was characterized predominantly by normal slip with slight right-lateral strike-slip components, which suggest that the Indian plate compresses the Eurasian plate northeastward, which produces near East-West tension in southern Tibetan Plateau. The study of Coulomb stress change showed that the Nepal M(W)7.9 earthquake and its aftershocks, together with four historical earthquakes in Dingri area, triggered the 2020 Dingri M(W)5.6 earthquake. The Coulomb stress change caused by afterslip in two years of the Nepal earthquake accounts for similar to 40% the total Coulomb stress increase, which indicates that the role of the afterslip in seismic risk assessment cannot be ignored.

Since the late Cenozoic, the reactivated Tianshan orogenic belt has accommodated crustal shortening exceeding 200 km, primarily due to the far-field effects of the India-Eurasia plate collision. However, the details of the strain partitioning in the Tianshan Mountain range remain elusive. We interpret a new compilation of GPS velocities covering the whole Tianshan range with a classic elastic block model. Compared to previous studies with a block modeling approach, the Tianshan orogenic belt is further subdivided into several blocks based on geological fault traces and a clustering analysis approach. In addition to obvious crustal shortening on the bounding thrust faults of the Tianshan, our inverted fault slip rates also reveal that faults within the Tianshan orogenic belt, such as the Nalati Fault and the southern margin of the Issyk-Kul Lake Fault, which plays a crucial role in accommodating the tectonic crustal shortening. In the 72°E−78°E region, the internal shortening rate within the mountain is approximately 5–7 mm/yr. Besides crustal shortening, strike-slip motion occurs on faults in the interior of the mountain range as well as in the foreland fold-and-thrust belts, especially in the southern margin of the Tianshan. These findings suggest that the crustal deformation in the Tianshan Mountain range is more complex than previously thought, and the oblique convergence between the Tarim Basin and the Tianshan probably results in both strike-slip and thrust motion.

Contemporary kinematic characteristics of the Pamir plateau are characterized by (a) significant NS-shortening across the northern front, (b) EW-extension within the Pamir and (c) gravitationally driven westward mass-outflux of the western Pamir into the Tajik basin. The 2015 Mw 7.2 Sarez and 2023 Mw 6.8 Murghab strike-slip earthquakes highlight the crucial role of shear deformation in the Pamir's interior, but the detailed secular kinematics of the remote Plateau are still elusive. Here, we employ elastic block models to fit GNSS velocities compiled from our own reprocessed velocity solution and from previous studies to determine slip rates along major active faults within and bounding the Pamir plateau. Our favored model separates the Pamir's interior into three micro-blocks along the NNE-trending sinistral Sarez-Karakul fault system and the SSE-trending Kongur Shan extensional system. The model confirms significant crustal shortening along the Pamir's northern boundary and strike-slip motion along its western boundary, namely the Pamir thrust system and the Darvaz fault, respectively. In contrast, strike-slip motion on the eastern boundary is minor. In the interior of the Plateau, we find an upper limit of sinistral shear of 8.8 +/- 0.3-9.5 +/- 0.2 mm/yr along the Sarez-Karakul fault system and dextral shear of 6.3 +/- 0.3 mm/yr along the WNW-trending Muji fault. Our model also confirms recent observations of an active, SW-continuation of the Sarez-Karakul fault system. In the eastern Pamir, crustal extension mainly occurs across the northern segment of the Kongur Shan extensional system. The recent large strike-slip earthquakes on the Pamir plateau suggest that shear motion on the plateau is accommodated on a much wider range than only by the Sarez-Karakul fault system.

SUMMARY The 2022 Har Lake earthquake sequence, which began in 2022 January and lasted for ∼70 d, jolted the Har Lake area, which is located in the western Qilian Shan, northeastern Tibetan Plateau. Two Mw > 5.5 earthquakes occurred during the earthquake sequence, among which the March 25 Mw 5.8 event is considered the largest event recorded in the area. However, determining the seismogenic faults of the earthquake sequence, as well as the detailed rupture features, is difficult due to the lack of geological data and near-field seismological observations. In this study, we use Sentinel-1 synthetic aperture radar (SAR) data to obtain the coseismic deformation field, identify possible ruptured faults and associated fault geometries, and further estimate detailed coseismic slip models of the two Mw > 5.5 earthquakes. The results show that the January 23 Mw 5.6 earthquake (Earthquake A) occurred on a N15° W-trending dextral-slip fault with a dip angle of ∼61°. For the March 25 Mw 5.8 earthquake (Earthquake B), the interferometric synthetic aperture radar (InSAR) data can be described by either an ∼N–S-trending dextral-slip fault or an ∼E–W-trending sinistral-slip fault. The ∼N–S-trending fault better describes the aftershock distribution, while the ∼E–W-trending model is more consistent with the regional geological setting. We suggest that the complex coseismic ruptures in the multiple-fault system are driven by widespread NE–SW-trending compression in the western Qilian Shan. This study demonstrates the importance of integrating geodetic and seismological observations to capture the full complexity of moderate earthquakes and further suggests potential seismic hazards in the Har Lake area.