The 21 May 2021 Maduo earthquake occurred on the Kunlun Mountain Pass–Jiangcuo fault (KMPJF), a seismogenic fault with no documented large earthquakes. To probe its kinematics, we first estimate the slip rates of the KMPJF and Tuosuo Lake segment (TLS, ∼75 km north of the KMPJF) of the East Kunlun fault (EKLF) based on the secular Global Positioning System (GPS) data using the Markov chain Monte Carlo method. Our model reveals that the slip rates of the KMPJF and TLS are 1.7 ± 0.8 and 7.1 ± 0.3 mm/yr, respectively. Then, we invert high‐resolution GPS and Interferometric Synthetic Aperture Radar observations to decipher the fault geometry and detailed coseismic slip distribution associated with the Maduo earthquake. The geometry of the KMPFJ significantly varies along strike, composed of five fault subsegments. The most slip is accommodated by two steeply dipping fault segments, with the patch of large sinistral slip concentrated in the shallow depth on a simple straight structure. The released seismic moment is $∼1.5×1020N·m$⁠, equivalent to an $Mw$ 7.39 event, with a peak slip of ∼9.3 m. Combining the average coseismic slip and slip rate of the main fault, an earthquake recurrence period of $∼1250−400+1120yr$ is estimated. The Maduo earthquake reminds us to reevaluate the potential of seismic gaps where slip rates are low. Based on our calculated Coulomb failure stress, the Maduo earthquake imposes positive stress on the Maqin–Maqu segment of the EKLF, a long‐recognized seismic gap, implying that it may accelerate the occurrence of the next major event in this region.

High‐rate (≥1 Hz) real‐time Global Navigation Satellite Systems (GNSS) data have been now incorporated into earthquake early warning systems where dense GNSS network exists, like the United States west coast, Japan, and so on. In this manuscript, we exploit the potential of rapid moment magnitude (⁠ $Mw$⁠) estimation in Sichuan–Yunnan region using GNSS records from Crustal Movement Observation Network of China (CMONOC) for seven magnitude (M) ≥ 6 events from 2011 to 2020. We find that currently it is still quite challenging to get reliable $Mw$ using the peak ground displacement or peak ground velocity approach, which is caused by the sparse stations and probably the inaccurate scaling law itself. By contrast, the $Mw$ estimations from focal mechanism grid search are all consistent with Global Centroid Moment Tensor catalog, even by one station. Considering the CMONOC network is going to be densified in the coming decade, it is expected that high‐rate GNSS waveforms will play a more important role in fast postevent response.

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 $1.1×1019N·m$ 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.

Rapid acquisition of the kinetics deformation field and seismic intensity distribution of large earthquakes is crucial for postseismic emergency rescue, disaster assessment, and future seismic risk research. The advancement of GNSS observation and data processing makes it play an important role in this field, especially the high-frequency GNSS. We used the differential positioning method to calculate the 1 HZ GNSS data from 98 sites within 1000 km of the M_S7.4 Maduo earthquake epicenter. The kinetics deformation field and the distribution of the seismic intensity by using the peak ground velocity derived from displacement waveforms were obtained. The results show that: 1) Horizontal coseismic response deformation levels ranging from 25 mm to 301 mm can be observed within a 1000 km radius from the epicenter. Coseismic response deformation on the east and west sides shows bilateral asymmetry, which markedly differs from the symmetry presented by surface rupture. 2) The seismic intensity obtained through high-frequency GNSS and field investigations exhibits good consistency of the scope and orientation in the high seismic intensity area, although the former is generally slightly smaller than the latter. 3) There may exist obstacles on the eastern side of the seismogenic fault. The Maduo earthquake induced a certain tectonic stress loading effect on the western Kunlun Pass-Jiangcuo fault (KPJF) and Maqin-Maqu segment, resulting in higher seismic risk in the future.

The 2021 M7.4 Maduo (China) earthquake ruptured a 170 km-long left-lateral fault within the Bayan Har tectonic block in the northeast Tibetan Plateau. We use Sentinel-1 and ALOS-2 Interferometric Synthetic Aperture Radar, and Global Navigation Satellite System data to investigate the mechanisms of coseismic and postseismic deformation due to the Maduo earthquake. We present a refined coseismic slip model that features variations in both strike and dip angles, constrained by the rupture trace and precisely located aftershocks. The postseismic displacements are discontinuous along the fault trace, indicating shallow afterslip and velocity-strengthening friction in the top 2-3 km of the upper crust. Postseismic displacements that have the same sense as the coseismic ones are also observed at larger (> 50 km) distances away from the fault trace. The observed surface deformation is qualitatively consistent with either deep afterslip or viscoelastic relaxation, but does not exhibit obvious features that could be attributed to poroelastic effects. We developed a fully coupled model that accounts for both stress-driven creep on a deep localized shear zone and viscoelastic relaxation in the bulk of the lower crust. The mid- to near-field data can be reasonably well explained by either deep afterslip or non-Maxwellian visco-elasticity. However, a good fit to both the near and far-field (> 150 km) GNSS data cannot be achieved assuming the bulk viscoelastic relaxation alone, and requires a contribution of deep afterlip and/or a localized shear zone extending through much of the lower crust.