The kinematic rupture process of the 2015 Illapel, Chile, earthquake is investigated based on a joint inversion of teleseismic, Interferometric Synthetic Aperture Radar, Global Positioning System, and tsunami data, as well as backprojection (BP) techniques. The coseismic slip area is determined to be $∼100×100km$ along strike and along dip, with a peak slip of $∼7.0m$ located $∼80km$ to the north‐northeast of the epicenter. The total seismic moment is estimated to be $2.5×1021N·m$ ($Mw$ 8.2). The rupture kinematics is featured by unilateral propagation along the strike and reverse rupture along the dip. In our model, the rupture bifurcates to up‐dip and down‐dip between 20 and 40 s. The downward rupture branch reaches the down‐dip border of the rupture area at 30–40 s, reverses its propagation direction, and migrates to the trench between 80 and 100 s. This is also revealed in the BP results in a wide frequency range. The aftershocks on the plate interface are complementary to the coseismic rupture area. Normal‐faulting aftershocks are observed in the out‐trench area, and its along‐strike extent is consistent with that of the near‐trench rupture. To determine the source duration of the main event, we compare the teleseismic waveforms of the mainshock and aftershocks at different depths. Coda waves after 100 s are observed in both the mainshock and shallow aftershock waveforms, with similar duration, relative amplitude, and characteristic period (16 s). This is consistent with a theoretical water‐reverberation‐phase period near the trench. Therefore, it suggests that the coda waves likely originate from water reverberation generated by shallow rupture, instead of from a prolonged source duration.

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.

Groundwater overexploitation is a critical issue in the North China Plain (NCP), resulting in groundwater level decline and surface subsidence for the last half-century. This problem, however, has been greatly alleviated by the South-to-North Water Diversion (SNWD) Project since 2015. Monitoring of this process has been steadily improved in recent years using water level and geodetic observations. Here, we characterize the water storage change at the Huairou groundwater reserve site (HGRS) in Beijing due to the SNWD by combining Interferometric Synthetic Aperture Radar (InSAR) data of the Sentinel-1 satellites, continuous Global Positioning System (GPS) data, and well water level data observed during the same time. InSAR observations revealed subsidence up to ~400 mm in the Beijing plain but uplift at ~40 mm in the HGRS during 2015–2019, and more than 70% of the uplift occurred from October 2018 to January 2019. By integrating the most significant uplift deformation during October 2018 to January 2019 with water level observations at the same time, we estimated the storativity of the confined aquifer system at HGRS as $1.68–7.82\times {10}^{-3}$, weighing in the correction for effective stress and surface deformation for various situations. Based on the estimated aquifer storativity and the observed water level change in the unconfined and confined aquifer, the recharged water storage for the confined and unconfined aquifers was estimated as $1.20–1.39\times {10}^7{ \mathrm{m}}^3$ and ~$2.86\times {10}^8{ \mathrm{m}}^3$ from 6 October 2018 to 22 January 2019, respectively, which is about 4% and 91% of the surface water recharge through river channels in the same period due to the SNWD Project. Our study demonstrates that integration of geodetic and hydrological data can provide crucial information for the assessment of groundwater circulation and assistance of groundwater management.