Abstract Defining a standardized ionospheric storm scale is challenging given the ionosphere's inherent complexity and susceptibility to multiple driving factors. In this study, a novel ionospheric storm scale (ISS) index is developed based on statistical analysis of total electron content (TEC) data from 257 ground‐based GNSS stations across China between 2008 and 2021. Designed for broad applicability, the index is independent of season, local time, and geographic location. We first derive an ionospheric activity index in percentage by comparing observed TEC values with a quiet‐time reference. To account for seasonal, diurnal, and latitudinal variations in TEC fluctuations, each percentage deviation is normalized using the robust Z‐score method. The ISS is then established by defining thresholds for the normalized data, categorizing activity into seven levels: ISS0, ISS P 1, ISS P 2, ISS P 3, ISS N 1, ISS N 2, and ISS N 3. Results reveal that the new index exhibits no diurnal or seasonal dependence, a key requirement for a homogeneous ionospheric activity time series. Correlation analysis between the ionospheric activity index and the residuals of the ionospheric TEC model we developed previously, along with variations in the index during geomagnetic storms, demonstrates that the ISS can serve as a reliable indicator of the expected performance of ionospheric models and well represents ionospheric activity. Finally, analysis of the relationship between standard point positioning accuracy and the ionospheric activity index under different solar activity levels reveals that higher ionospheric activity corresponds to increased positioning errors during periods of high solar activity.

Abstract The Mongolian plateau, formed during the Mesozoic, represents a typical intracontinental plateau in East Asia that has maintained elevated topography over geological time. Its deep lithospheric structure and underlying geodynamic mechanisms are therefore crucial for understanding the formation and long-term evolution of intracontinental plateaus. However, owing to sparse seismic station coverage and insufficient observational density, the overall region of the Mongolian plateau has long lacked sufficient seismic data. To address this limitation, several Chinese and Mongolian research institutions jointly deployed a large-scale temporary broadband seismic array covering the entire territory of Mongolia, referred to as China Array for Mongolia (CAM). This article presents the scientific motivations, instrument performance tests, station deployment strategies, and preliminary data quality assessment of the CAM array. Analyses of early recordings from CAM stations, complemented by comparisons with nearby permanent broadband stations, indicate that despite the use of a simple shallow-burial deployment strategy, the CAM stations achieve data quality comparable with that of permanent stations, particularly in their capability to record teleseismic body waves. Based on teleseismic event statistics and synthetic travel-time simulations, we further provide a conservative estimate of the array’s resolving ability, indicating that the CAM is capable of resolving lithospheric-scale velocity anomalies beneath the Mongolian plateau with a spatial resolution of approximately 100 km. The CAM array thus provides a critical seismic data set for constructing high-resolution crust–mantle structural models and for ultimately constraining the deep origins of the “exceptionally long-lived” Mongolian plateau.

Near-fault ground motions exhibit high intensity and pronounced spatial heterogeneity, posing severe threats to engineering structures. Current seismic design codes employ empirical coefficients to account for near-fault effects; however, spatial variation characteristics of near-fault ground motion fields remain insufficiently quantified. This study investigates the Nankou-Sunhe Fault in the Beijing region using the stochastic finite-fault method (SFFM) and probabilistic seismic hazard analysis (PSHA) to simulate spatially non-uniform distributions of near-field seismic motion under an Mw7.5 earthquake scenario. SFFM simulations reveal distinct PGA segmentation patterns: the northern Changping-Baishan segment forms localized high-value zones (PGA approximate to 520 gal) extending approximately 12 km along the strike; the central Shahe-Sunhe segment establishes a continuous beltshaped high-value zone (PGA approximate to 530 gal) spanning approximately 25 km with a width of 5-8 km; the southern Tongzhou segment maintains PGA approximate to 490 gal over approximately 15 km. PSHA results demonstrate that at the 3500-year return period, PGA peaks reach 520-530 gal for a focal depth of 10 km versus 395 gal for 15 km, reflecting a 25% reduction attributable to depth effects. The empirical PGA attenuation model for fault distances of 0-10 km achieves coefficients of determination (R2) ranging from 0.86 to 0.93, with attenuation rates of 29 gal/km (0-5 km) and 16 gal/km (5-10 km), thereby validating the 5 km segmentation threshold specified in current design codes. Cross-validation between SFFM and PSHA yields a spatial overlap coefficient of 76.2% overall (80.3% in the central segment), a Pearson correlation coefficient (r) of 0.96, and a normalized root-meansquare error of 9.5%. These findings provide theoretical foundations for incorporating near-fault ground motion effects into structural seismic design and for refining seismic design codes.

This study explores the velocity structure of the 2025 Mw7.7 Myanmar earthquake source region using seismic wave traveltime reciprocity tomography, a method that leverages the reciprocal relationship between sources and receivers to address the challenge of sparse station coverage. This inversion resolves robust velocity anomalies and remains generally stable with respect to the changes in the spatial extent of the study area. Tomographic results reveal a prominent north-south low-velocity zone that extends along the north-south trending Sagaing Fault, highlighting its role as the primary rupture zone. To the east of the fault, a broad high-velocity anomaly likely marks the steeply eastward-subducting Indian Plate beneath the Shan Plateau, whereas to the west, a localized high-velocity feature is consistent with a near-horizontal slab morphology beneath the Myanmar Central Basin. These findings provide new constraints on the deep structure and geodynamic processes beneath Myanmar.

The Qilian Shan, located at the northeastern edge of the Tibetan Plateau (NETP), has undergone complex tectonic evolution and serves as an ideal region for studying the growth of the Tibetan Plateau. However, the mode of lithospheric deformation beneath the Qilian Shan remains a subject of debate. In this study, we use the common conversion point stacking technique with P and S receiver functions, calculated from waveform data recorded by a seismic array consisting of 153 broadband stations, to obtain images of crustal and upper mantle discontinuities beneath the NETP and adjacent Alxa block. Our findings reveal that the Moho depth beneath the NETP is greater than that beneath the Alxa block, with the deepest Moho located beneath the North Qilian area. A sudden decrease of similar to 10 km in the Moho depth occurs from the North Qilian fault to the Alxa block. The lithosphere-asthenosphere boundary is clearly identifiable in our data, showing a continuous, southward-dipping interface from the Alxa block to the Qilian Shan. Integrating geophysical and geological results, we propose that passive underthrusting of the Asian Plate occurs beneath the Qilian Shan. This process, influenced by the strong obstruction of the Alxa block during the expansion of the NETP, leads to the accumulation of lithospheric mantle material and crustal thickening and causing the lithospheric mantle of the Asian Plate to bend and undergo southward underthrusting beneath the Qilian Shan.

Coal mining industry has complex geological conditions, high safety risks, frequent mine dynamic disasters such as rock burst, coal and gas outburst, which are the core problems restricting the safe production of coal mines and affecting the high-quality development of the industry. The traditional disaster prevention and control technology is mainly concentrated in the combination of local areas of the mine field and a single influencing factor, which is difficult to adapt to the complex geological environment of multi plate intersection and active tectonic activity in China. There are problems such as insufficient prediction accuracy, weak prevention and control pertinence, and imperfect technical system. In view of the above difficulties, this paper systematically combs the whole process of the introduction, adaptation, iterative optimization and independent innovation of the geo dynamic zoning theory in China for more than 30 years, focuses on the application scenarios in the field of mine safety, summarizes and sorts out the technical iteration process, core innovation achievements, engineering application achievements and existing technical shortcomings of the theoretical system, and systematically improves the geo dynamic zoning research system and engineering application paradigm adapted to China’s geological characteristics. Using the research methods of theoretical innovation, technology research and development, system integration and engineering verification, relying on the theory of plate tectonics and the principle of geodynamics, breaking through the limitations of the application of Russia's primary geodynamic zoning theory, and combining the regional geological characteristics of the intersection of three tectonic domains, the development of fault structures, and the active neotectonic movement in China, we carried out multi-dimensional and multi-level technological innovation and practice optimization. At the basic theoretical level, the "three conditions" criterion for the occurrence of mine dynamic disasters is established, the coupling mechanism of the three core elements of geological dynamic environment, mining disturbance and prevention and control measures is clarified, the national first-class geological dynamic zoning work is completed, the national geological dynamic cell bureau is divided, the macro spatial distribution characteristics of "1-1-0" of mine dynamic disasters in China are revealed, and the differential distribution characteristics of disasters in the Tan Lu fault zone, the Qinling Dabie orogenic belt and the Sichuan basin tectonic area are clarified, which provides a theoretical basis for the prevention and control of mine disasters at the national scale. At the technical method level, three core methods, namely multi factor pattern recognition risk prediction, quantitative evaluation of geo dynamic environment and evolution analysis of coal and rock dynamic system, have been formed to break through the limitations of traditional single geological factor analysis and realize the transformation of mine dynamic disasters from qualitative research and judgment to quantitative prediction and from local analysis to overall analysis. At the system R&D level, three software systems are developed iteratively, including rock mass stress state analysis, multi factor pattern recognition risk prediction, and geo dynamic zoning information management. An integrated data integration and visual management platform is built to achieve efficient integration and intelligent analysis of geological data, structural parameters, stress data, and disaster information. In terms of monitoring technology, integrate the global navigation satellite system (GNSS), interferometric synthetic aperture radar (InSAR) surface deformation monitoring, mobile seismic network seismic monitoring, and underground fault activity dynamic monitoring technology, build an integrated surface-underground multidimensional monitoring system, and effectively improve the ability of mine dynamic disaster precursor information capture and risk prediction. Relying on theoretical and technological innovation, the research team has formed a patented technology and industry standard system covering disaster prediction, monitoring, prevention and control. Relevant technical concepts have been incorporated into the 2016 version of the coal mine safety regulations and the 2018 version of the detailed rules for the prevention and control of coal mine rockburst, realizing the deep integration of scientific research achievements and industry standards. By comparing the research systems at home and abroad, it is found that there are some problems in foreign related research, such as difficulty in adapting to deep complex engineer scenes and limited engineering practicability. China’s research has formed significant technical advantages in multi factor coupling analysis, quantitative prediction, engineering adaptability, and systematic application. At the same time, identify the shortcomings of the current research, including the lack of disaster prediction accuracy under complex geological conditions, the low level of technical intelligence, and the lack of dynamic adaptive prevention and control ability. Based on the existing research foundation, in the future, we will focus on technical breakthroughs such as optimization of generalized pattern recognition algorithm, intelligent automatic division of fault block structure, accurate simulation of three-dimensional rock mass stress, and dynamic application evaluation of geo dynamic environment, integrate cutting-edge technologies such as big data, artificial intelligence, and machine learning, build an intelligent, refined, and integrated geo dynamic zoning technology system, promote the in-depth integration of geo dynamic zoning and mine dynamic disaster prevention and control technology, comprehensively improve the level of intelligent prevention and control of coal mine dynamic disasters in China, and provide solid theoretical support and technical support for mine safety production and high-quality development of the industry.

High-rate Global Navigation Satellite Systems (hrGNSS) provide clip-free, geodetically referenced displacement time series that are valuable for resolving near-field earthquake dynamics. Here, we analyze ultra-high-rate (50 Hz) and conventional (1 Hz) hrGNSS data from the 2022 Luding MW6.8 and the 2025 Dingri MW7.1 earthquakes. We process the data using both differential positioning and precise point positioning (PPP), and evaluate single-GPS, GPS-GLONASS-Galileo (GRE), and GPS-GLONASS-Galileo-BeiDou-2 (GREC2) solutions. The GREC2 combination significantly reduces positioning noise relative to GPS-only, with improvements of 2%–23% and 49%–83% on the east- and north-components, respectively, while GRE shows smaller but systematic gains (east 2%–24%, north 30%–72%). Differential positioning shows slightly lower noise than PPP, i.e., about 14% east, about 6% north on average, despite a sub-centimeter precision for both approaches. The near-fault 50 Hz waveforms in the Luding event feature the resolvable energy within the 0.3–0.5 Hz band, implying potential aliasing in 1 Hz records. These results demonstrate that integrating BeiDou Navigation Satellite System (BDS) can improve the precision of dynamic displacements. However, the 1 Hz sampling rate may be susceptible to aliasing effects when the site is located near the fault.

This study investigates the seismogenic characteristics of the 2025 Dingri MS 6.8 earthquake through multi-parametric GNSS analyses of velocity field, strain rate evolution and displacement patterns across pre-seismic and co-seismic phases. Our findings demonstrate spatiotemporally heterogeneous crustal deformation exhibiting kinematic precursors correlating with subsequent rupture propagation. The epicentral region exhibited prolonged N-S compressional strain accumulation accompanied by accelerated E-W extensional deformation and progressive counterclockwise rotation of principal strain axes three years prior, indicating enhanced local normal fault activities. Co-seismic observations delineate significant displacement domains, with the XZSJ (∼95 ​mm) site documenting the largest northeastward motion, consistent with rupture propagation along secondary N-E trending structures. Co-seismic strain analysis identifies concentrated seismic moment release primarily west of the Xainza-Dinggye Fault and north of the Southern Qinghai-Xizang Detachment Fault system, displaying normal fault kinematics in agreement with the seismic source mechanism. The co-seismic strain partitioning pattern shows critical implications for regional N-S trending normal fault system, necessitating sustained geodetic monitoring to advance understanding of seismic cycle deformation in this area.

The Changning region, located in the southern Sichuan Basin, has historically been regarded as tectonically stable. However, in recent years, seismicity has increased significantly alongside the expansion of large-scale industrial activities. The successive occurrences of the Xingwen MS5.7 and Changning MS6.0 earthquakes within a short interval have attracted considerable attention from both the seismological community and the public. To better understand the relationship between industrial activities and subsurface velocity structures, as well as their influence on seismicity, this study first selects a large number of high-quality P- and S-wave first arrival times from a dense array of temporary broadband seismic stations, and then conducts local earthquake traveltime tomography to invert for high-resolution P- and S-wave velocity models in the shallow crust beneath the Changning hydraulic fracturing zone. The results reveal that velocity heterogeneities are generally correlated well with stratigraphic age, while localized velocity anomalies near industrial extraction layers are associated with injection pressure variations. Moreover, a low P-wave velocity anomaly forms a continuous belt linking the Xingwen and Changning seismic zones, indicative of a deep subsurface fluid migration channel. Although alternative seismogenic mechanisms cannot be ruled out, this finding preferentially supports a hypothesis in which fluid migration along a long-distance channel activated by the Xingwen earthquake contributes to the initiation of the Changning earthquake.

The Belt and Road global navigation satellite system (B&R GNSS) network is the first large-scale deployment of Chinese GNSS equipment in a seismic system. Prior to this, there have been few systematic assessments of the data quality of Chinese GNSS equipment. In this study, data from four representative GNSS sites in different regions of China were analyzed using the G-Nut/Anubis software package. Four main indicators (data integrity rate, data validity ratio, multi-path error, and cycle slip ratio) used to systematically analyze data quality, while evaluating the seismic monitoring capabilities of the network based on earthquake magnitudes estimated from high-frequency GNSS data are evaluated by estimating magnitude based on high-frequency GNSS data. The results indicate that the quality of the data produced by the three types of Chinese receivers used in the network meets the needs of earthquake monitoring and the new seismic industry standards, which provide a reference for the selection of equipment for future new projects. After the B&R GNSS network was established, the seismic monitoring capability for earthquakes with magnitudes greater than MW6.5 in most parts of the Sichuan-Yunnan region improved by approximately 20%. In key areas such as the Sichuan-Yunnan Rhomboid Block, the monitoring capability increased by more than 25%, which has greatly improved the effectiveness of regional comprehensive earthquake management.

Accurate estimation of Zenith Tropospheric Delay (ZTD) is essential for mitigating atmospheric effects in radio astronomical observations and improving the retrieval of precipitable water vapor (PWV). In this study, we first analyze the periodic characteristics of ZTD at the NanShan Radio Telescope site using Fourier transform, revealing its dominant seasonal variations, and then investigate the correlation between ZTD and local meteorological parameters, to better understand atmospheric influences on tropospheric delay. Based on these analyses, we propose a hybrid deep learning Gated Recurrent Units-Long Short-Term Memory model, incorporating meteorological parameters as external inputs to enhance ZTD forecasting accuracy. Experimental results demonstrate that the proposed approach achieves a Root Mean Squared Error of 7.97 mm and a correlation coefficient R of 96%, significantly outperforming traditional empirical models and standalone deep learning architectures. These findings indicate that the model effectively captures both short-term dynamics and long-term dependencies in ZTD variations. The improved ZTD predictions not only contribute to reducing atmospheric errors in radio astronomical observations but also provide a more reliable basis for PWV retrieval and forecasting. This study highlights the potential of deep learning in tropospheric delay modeling, offering advancements in both atmospheric science and geodetic applications.

Rock burst is the result of the coupling effect of geological dynamic environment and mining engineering disturbance.The crustal deformation characteristics of mining area are one of the important influencing factors of geological dynamic environment,which can directly reflect the dynamic evolution characteristics of stress deformation-instability of overlying coal and rock mass structure in un-derground working face mining.The disturbance of mining engineering increases the stress of coal and rock mass and accumulates energy.When the critical condition of coal and rock is reached,it is easy to induce the instantaneous release of energy and cause the disaster of rock burst.Therefore,there is a close relationship between the regional crustal deformation characteristics and rock burst in the mining area.In order to deeply analyze the relationship between the crustal deformation characteristics and the micro-seismic energy events of rock burst in the mining area,based on the InSAR monitoring data of Hegang mining area,the temporal and spatial evolution characterist-ics of surface deformation in Fuli coal mine,Xing'an coal mine and Junde coal mine were studied.Taking the second section of the work-ing face of the 17-layer three-four area of Junde coal mine as an example,the InSAR monitoring results of 10 points in the region were se-lected,and the average crustal deformation characteristics and the total energy of rock burst micro-seismic were comprehensively ana-lyzed,and the"time-space-strong"characteristics of the occurrence of high-energy micro-seismic events and regional crustal deformation were quantitatively determined.The research shows that the vertical deformation of the crust in the mine field of Junde Coal Mine is con-sistent with the total energy change trend of the 17-layer microseismic events,reaching 69%,and there is a high consistency in time fre-quency.The energy of 24 large-energy microseismic events in the typical period(2020-12-02-2021-12-28)and the average deforma-tion of 10 monitoring points were selected for Pearson correlation analysis.It was concluded that the magnitude of microseismic energy was positively correlated with the average deformation,and the correlation coefficient was 0.56.The epicentral distance was negatively correlated with the average deformation,and the correlation coefficient was-0.75,which reflected the spatial and intensity relationship between crustal deformation characteristics and rock burst.It shows that InSAR monitoring has a high degree of matching with microseis-mic events in time,space,deformation and microseismic monitoring.

Decoding both surface deformation and underlying fault kinematics is of great significance for understanding earthquake physics and assessing seismic hazards. Herein, we compile the interseismic, coseismic, and postseismic InSAR deformation from 2014 to 2022 associated with the 2022 Ms 6.9 Menyuan earthquake and decipher the underlying creeping rate, seismic rupture, and stress-driven afterslip. Our results show that the dynamic rupture of the Menyuan event is precluded on the west by a creeping section and on the east by a highly locked section, which may be a stress barrier with high seismic potential. Its coseismic slip is mainly distributed within the high-coupling patch, and the afterslip occurred dominantly downdip of the coseismic asperity, an area also characterized by interseismic creeping, in line with the slip pattern predicted by the rate-and-state frictional framework. Afterslip and aftershocks are concentrated in regions of positive Coulomb failure stress changes (Delta CFS) due to the coseismic slip, and the increased Delta CFS is released >70 % aseismically and <30 % seismically by aftershocks. Finally, we introduce a conceptual model for this seismogenic fault to describe fault behaviors as well as frictional properties during the earthquake cycle. This study contributes valuable insights into the slip evolution, slip budget, and frictional behaviors of continental strike-slip fault systems.

Abstract Equatorial plasma bubble (EPB) irregularities can significantly impact satellite‐based communication and navigation systems. Accurate prediction of EPB occurrence is essential for mitigating these impacts. Using the GNSS receiver network and ionosonde data from East and Southeast Asia during 2010–2021, and the rate of TEC change index to characterize the occurrence of EPB irregularities, we developed a novel Spatio‐Temporal deep learning model for regional EPB irregularities short‐term Prediction (STEP). The model integrates the convolutional neural network and long short‐term memory (LSTM) network, together with attention mechanisms, to capture both spatial and temporal features of regional ionospheric irregularities. The results show that for 5‐min forecast, the STEP model achieves a root mean square error (RMSE) of 0.062 TECU/min and an R2 of 0.818, reducing RMSE by 19.48% compared to LSTM and 27.06% compared to gated recurrent unit model. For 60‐min prediction, the STEP model can still achieve reasonable accuracy with an RMSE of 0.110 TECU/min and an R2 of 0.482, showing significant improvement over traditional models. The equatorial F layer height and regional TEC fluctuations were identified as the most critical factors for predicting the generation and duration of EPB irregularities, respectively. The spatial and temporal distributions of EPB irregularities, including their latitudinal variation and delayed onset after sunset, and the occurrence across different days in East and Southeast Asia, were well predicted by the STEP. It is expected that the STEP model would provide a valuable tool for improving the resilience of GNSS against ionospheric scintillations induced by EPB irregularities.

Using total electron content (TEC) data from multiple ground‐based Global Navigation Satellite System (GNSS) receiver networks from 2010 to 2023, we reconstructed ionospheric TEC maps for East Asia. The maps cover longitudes from 70°E to 150°E and latitudes from 20°S to 60°N. The time resolution of reconstructed TEC map was 15 min. The region with the best latitude coverage of GNSS TEC observations is found between 100°E and 110°E. Consequently, we used the TEC latitudinal profile data at 105° longitude for empirical orthogonal function decomposition, which allowed us to derive a set of orthogonal basis functions for the TEC latitudinal profile. Using these basis functions, we fitted the TEC latitude profile for each meridian plane. By combining the results from the TEC latitudinal profiles across all meridian planes from 70°E to 150°E, we created the regional TEC maps. Comparing the observed TEC data with the CODE TEC maps reveals that the CODE maps contain consistent errors in the East Asian sector, primarily due to limited data availability in this region, particularly in China. Furthermore, comparisons with Jason's TEC data over the oceans demonstrated that our reconstructed TEC map could still accurately reproduce the latitude profile, even with some missing data at some latitudes. This reconstructed regional TEC maps provide us a crucial data product that can assist us in statistically analyzing finer structural features of the ionosphere in this region.

The Haiyuan-Liupan Shan(HY-LPS) arcuate tectonic belt, located at the junction of the growth front of the Tibetan Plateau and the North China Craton, serves as a natural laboratory for investigating continental collision. Investigating the fine structure and dynamic processes in this area not only deepens our understanding of the debated growth and deformation patterns of the plateau, but also clarifies the interactions between the plateau and the adjacent craton. In this study, we establish a highresolution three-dimensional crustal shear-wave velocity structure surrounding the HY-LPS arcuate tectonic belt using the surface wave imaging technique, utilizing ambient noise data from 219 broadband stations. The shear-wave velocity structure in this region exhibits a strong correlation with geological tectonics, consistent with the transformation of boundary faults from strike-slip to thrust. Low-velocity bodies are extensively distributed in the middle crust of the Longxi block, which is located at the northeastern margin of the Tibetan Plateau. The formation of these low-velocity anomalies may result from multifactorial interactions. Our results indicate that the upper and lower crusts in the Longxi block are decoupled, and the mid-crustal lowvelocity bodies act as a detachment layer. This decoupling mechanism facilitates the growth of the plateau margin by enabling the upper crust to overthrust onto the craton, thereby contributing to the formation of the Liupan Shan. Furthermore, the lower crust of the Longxi block is found thickened due to the obstruction imposed by the North China Craton and intruded into the cratonic lower crust. The cratonic crust has been compromised due to the combined effects of tectonic compression and thermal erosion associated with the northeastward expansion of the Tibetan Plateau, which has facilitated the development of wedge tectonics.

This article has summarized the shortcomings and deficiencies in the construction and operation of the earthquake monitoring station network of China, analyzes the trend of modernization development of the monitoring station network, and proposes measures and suggestions for upgrading and replacing the earthquake monitoring network of China from the perspective of a new development philosophy. It has also detailed the design and implementation of the national disaster prevention project.

Rocket-launching can trigger traveling ionospheric disturbances (TIDs) which often show V-shaped structures. Using a dense Global Navigation Satellite System total electron content (TEC) receiver network, we investigated the ionospheric response to the waves triggered by the launches of Long March (LM) series of rockets, the LM-2D on 30 March 2023 and LM-6A on 10 September 2023. Results show that during the two launches, large ionospheric holes and TIDs with unusual semicircular and circular structures were observed. The ionospheric disturbances traveled for a distance of more than 1,500 km with amplitudes gradually decreased from about 0.1 to 0.03 TEC unit. The period and horizontal speed of disturbances were similar to 7-8 min and around 700-800 m/s, respectively, which fell into the acoustic mode. We suggest that the TIDs were induced by shock acoustic waves (SAWs). The semicircular and circular structures could be attributed to the rocket flight tilt angle and the corresponding altitude of conic SAWs.

Although groundwater levels (GWL) have gradually stabilized and even increased in some regions under human intervention, persistent land subsidence remains a concern. This situation underscores the urgent need to investigate the restoration mechanisms of the aquifer system, particularly focusing on the interconnected processes of groundwater dynamics and strata deformation. This study specifically concentrates on the Lubei Plain in the southeast of the North China Plain-a chief recipient area of the East Route of the South-to-North Water Diversion Project-to delve into these scientific inquiries. In this study, we utilize a limited amount of GNSS data to address InSAR atmospheric errors and employ a weighted least squares time series inversion method to enhance the robustness of the deformation time series. Furthermore, a blind source separation technique named Independent Component Analysis (ICA) is applied to separate mixed signals of InSAR, successfully isolating deformation signals from both the sand and clay layers within the aquifer system, as well as those induced by environmental loadings. These approaches significantly facilitate the exploration of the interactive processes between groundwater dynamics and strata deformation. The result reveals a complex relationship between GWL and surface deformation during the aquifer system's recovery stage due to the distinct responses of the sand and clay layers to groundwater dynamics. We find that during the restoration phase of aquifer system (when recharge exceeds discharge), the sand layers undergo recovery and rebound firstly, while weakly permeable clay layers continue to consolidate. (c) 2025 COSPAR. Published by Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

The Sichuan-Yunnan block is located at the southeastern margin of the Tibetan Plateau, which is the key area as a transition belt from the active plate extrusion zone to the stable Yangtze Craton. Using a semiautomatic measuring method based on a graphical interface, we pick 81,585 precise travel times from 449 local earthquake records and finally obtain a crustal 3D P-wave velocity model of the Sichuan-Yunnan block. The model reveals an unexpected velocity contrast between the shallower and deeper crusts. It is summarized as weakly perturbed low-velocity belts encircling a high-velocity zone in the upper crust and strongly perturbed low-velocity anomalies in the mid-lower crust, respectively. The weak low-velocity anomalies are revealed along the major strike-slip faults, and their small perturbations may imply a slip-driven mechanism. The strong low-velocity anomalies are distributed extensively in the Sichuan-Yunnan block, and their great perturbations may be related to the partial melting of weak material extruded from Tibet. Besides, our result shows noticeable high-velocity anomalies in the core zone of the Emeishan Large Igneous Province (ELIP), which may be an indication of magma solidification from the ancient mantle plume. The result further exhibits an interesting pattern that the strong low-velocity anomalies are partially separated by the high-velocity anomalies in the ELIP. Such a specific pattern probably reflects that the stable zone in the ELIP leads to the bifurcation of weak Tibetan material.