The ascending and descending interferometric synthetic aperture radar data are used to investigate the fault rupture and slip model of the 2018 Mw 7.5 Sulawesi, Indonesia, earthquake. The best fitting slip model indicates that this earthquake ruptured not only a segment extending the Palu fault to the north but also a northwestern segment offshore. The slip on the onshore fault is predominant left‐lateral strike slip. The slip on the offshore fault is dominated by normal faulting with a maximum slip of ~6.3 m. The newly discovered offshore normal faulting is likely to be the cause of the tsunami after the shock. Combined with previous geomorphic, tectonic, geodetic, and modeling studies, we suggest that the kinematics of the Palu fault maintained the same style of faulting from north to south, which resulted from an oblique extension occurred on an east dipping fault at depths. The deformation pattern of NW Sulawesi is dominated by this slip mechanism.

Interferometric synthetic aperture radar (InSAR) data from 6 Envisat ASAR descending tracks; spanning the 2003–2010 period; was used to measure interseismic strain accumulation across the Northeastern Tibetan Plateau. Mean line-of-sight (LOS) ratemaps are computed by stacking atmospheric-corrected and orbital-corrected interferograms. The ratemaps from one track with different atmospheric-corrected results or two parallel; partially overlapping tracks; show a consistent pattern of left-lateral motion across the fault; which demonstrates the MERIS and ECMWF atmospheric correction works satisfactorily for small stain measurement of this region; even with a limited number of interferograms. By combining the measurements of InSAR and GPS; a fine crustal deformation velocity and strain rate field was estimated on discrete points with irregular density depending on the fault location; which revealed that the present-day slip rate on the Haiyuan fault system varies little from west to east. A change (2–3 mm/year) in line-of-sight (LOS) deformation rate across the fault is observed from the Jinqianghe segment to its eastern end. Inversion from the cross-fault InSAR profiles gave a shallow locking depth of 3–6 km on the main rupture of the 1920 earthquake. We therefore infer that the middle-lower part of the seismogenic layer on the 1920 rupture is not yet fully locked since the 1920 large earthquake. Benefit from high spatial resolution InSAR data; a low strain accumulation zone with high strain rates on its two ends was detected; which corresponds to the creeping segment; i.e., the Laohushan fault segment. Contrary to the previous knowledge of squeezing structure; an abnormal tension zone is disclosed from the direction map of principal stress; which is consistent with the recent geological study. The distribution of principal stress also showed that the expanding frontier of the northeastern plateau has crossed the Liupan Shan fault zone; even arrived at the northeast area of the Xiaoguan Shan. This result agrees with the deep seismic reflection profile.

Residual noise effect in interferometric synthetic aperture radar (InSAR) time-series data typically complicates the characterization of deformation behaviors on tectonic faults, especially postseismic deformation caused by multiple physical mechanisms. To reconstruct denoised postseismic deformation signal in noisy InSAR time-series (TSInSAR) data, we proposed a deep-learning-based neural network and trained it on noisy TSInSAR dataset, which was generated by adding Sentinel-1 TSInSAR noise onto synthetic postseismic deformation. The application results on experimental dataset validated that our neural network efficiently removed residual noise and automatically recovered clean postseismic deformation in noisy TSInSAR with any space and time sizes. Moreover, when applied to real TSInSAR data following the 2021 Maduo earthquake, our network provided accurate reconstructions of postseismic deformation in both time and space, demonstrating its generalization performance on actual data. In comparison with the original data, the denoised postseismic deformation exhibits greater consistency with the observations from a continuous global positioning system (cGPS). Interestingly, our denoised postseismic slip reveals spatial juxtaposition between the geometrically complex coseismic rupture segments and the heterogeneity of the early afterslip along the Maduo rupture. Overall, these successful applications highlight the network’s generalization performance to improve postseismic deformation signals.

In this article the ascending and descending Sentinel-1A satellite data are used to investigate the coseismic slip model of the 2022 Mw6.7 Menyuan earthquake in Qinghai, China. The optimal slip model indicates that this event ruptured two fault segments. The main rupture concentrated on the western Lenglongling fault (LLLF) with a purely left-lateral striking-slip motion. A small part of the eastern Tuolaishan fault (TLSF) section was also ruptured, and the motion on it is mainly oblique slip at depth, with an obvious thrust component. Combined with the rupture characteristics of historical events, GPS velocity map, and slip rate studies, we suggest that the TLSF–LLLF junction is a demarcation point where the deformation partitioning pattern has changed. Along the whole LLLF segment, the oblique convergence has completely partitioned into slip on the purely strike-slipping LLLF and thrusting faults in the north. The TLSF segment accommodates a fraction of compressional shortening, which compensates for the discrepancy in the left-lateral slip rate between the LLLF and TLSF. Such transformation in the strain partitioning pattern is likely to be determined by the geometric relationship between the fault strike and the direction of regional block movement.

We obtained high-resolution (10 m) horizontal displacement fields from pre- and post-seismic Sentinel-2 optical images of the 2018 Mw7.5 Palu earthquake using subpixel image correlation. From these, we calculated the curl, divergence, and shear strain fields from the north-south (NS) and east-west (EW) displacement fields. Our results show that the surface rupture produced by the event was distributed within the Sulawesi neck (0.0974–0.6632°S) and Palu basin (0.8835–1.4206°S), and had a variable strike of 313.0–355.2° and strike slip of 2.00–6.62 m. The NS and EW displacement fields within the Palu basin included fine-scale displacements in both the near- and far-fault, the deformation patterns included a small restraining bend (localized shortening), a distributed rupture zone, and a major releasing bend (net extension) from the curl, divergence, and shear strain. Surface rupture was dominated by left-lateral strike-slip from initiation to termination, with a localized normal slip component peaking at ~3.75 m. The characteristics and geometric variation of the ruptured fault controlled both the formation of these surface deformation patterns and sustained supershear rupture.

The Pamir is located on the northwestern margin of the Tibetan Plateau, which is an area of intense continental deformation and part of the famous India–Himalaya collision zone. The dominant structural deformation in the eastern Pamir is characterized by a 250 km long east–west extensional fault system, known as the Kongur Shan extensional system (KSES), which has developed a series of faults with different orientations and characteristics, resulting in highly complex structural deformation and lacking sufficient geodetic constraints. We collected Sentinel-1 SAR data from December 2016 to March 2023, obtained high-resolution ascending and descending LOS velocities and 3D deformation fields, and combined them with GPS data to constrain the current motion characteristics of the northeastern Pamirs for the first time. Based on the two-dimensional screw dislocation model and using the Bayesian Markov chain Monte Carlo (MCMC) inversion method, the kinematic parameters of the fault were calculated, revealing the fault kinematic characteristics in this region. Our results demonstrate that the present-day deformation of the KSES is dominated by nearly E–W extension, with maximum extensional motion concentrated in its central segment, reaching peak extension rates of ~7.59 mm/yr corresponding to the Kongur Shan. The right-lateral Muji fault at the northern end exhibits equivalent rates of extensional motion with a relatively shallow locking depth. The strike-slip rate along the Muji fault gradually increases from west to east, ranging approximately between 4 and 6 mm/yr, significantly influenced by the eastern normal fault. The Tahman fault (TKF) at the southernmost end of the KSES shows an extension rate of ~1.5 mm/yr accompanied by minor strike-slip motion. The Kashi anticline is approaching stability, while the Mushi anticline along the eastern Pamir frontal thrust (PFT) remains active with continuous uplift at ~2 mm/yr, indicating that deformation along the Tarim Basin–Tian Shan boundary has propagated southward from the South Tian Shan thrust (STST). Overall, this study demonstrates the effectiveness of integrated InSAR and GPS data in constraining contemporary deformation patterns along the northeastern Pamir margin, contributing to our understanding of the region’s tectonic characteristics.