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The prompt and reliable determination of seismic source parameters, which provide information on earthquake location (LOC), magnitude (MAG), and focal mechanism (FM), is an imperative undertaking after a destructive earthquake. Deep learning (DL) techniques, owing to their excellent ability to extract pertinent features from waveforms, have gained growing popularity in addressing the challenge of rapid seismic source characterization. However, most existing DL models, particularly those for FM estimation, rely on a fixed configuration of stations. In this work, we propose a hybrid DL model tailored to probabilistic seismic source characterization using displacement waveforms from a flexible set of seismic or high rate Global Navigation Satellite System (HR-GNSS) stations. The proposed model encompasses a convolutional neural network (CNN) module, a graph module, and a mixture density network (MDN) module. Preliminary features are first extracted by the CNN module for each station. The graph module, where a graph attention network (GAT) branch and a maximum aggregation branch are included, then aggregates these features, enabling the adaptive learning of edge information among stations. The MDN module finally calculates the posterior probability distribution of each source parameter. The proposed model performed best compared to benchmark models within synthetic test datasets. The established model was then applied to estimate the source parameters of five events with $M > $ 5 in the 2019 Ridgecrest earthquake sequence and three other representative earthquakes worldwide. Probabilistic estimates that are consistent with known published ground-truth values could be obtained within seconds, verifying the effectiveness and efficiency of the proposed hybrid model in real-world scenarios.

ABSTRACTThe study aimed to identify the key active components in Silybum marianum(S. marianum) and determine how they protect against nonalcoholic fatty liver disease (NAFLD). TCMSP, DisGeNET, UniProt databases, and Venny 2.1 software were used to identify 11 primary active components, 92 candidate gene targets, and 30 core hepatoprotective gene targets in this investigation, respectively. The PPI network was built using a string database and Cytoscape 3.7.2. The KEGG pathway and GO biological process enrichment, biological annotation, as well as the identified hepatoprotective core gene targets were analyzed using the Metascape database. The effect of silymarin on NAFLD was determined using H&E on pathological alterations in liver tissues. The levels of liver function were assessed using biochemical tests. Western blot experiments were used to observe the proteins that were expressed in the associated signaling pathways on the hepatoprotective effect, which the previous network pharmacology predicted. According to the KEGG enrichment study, there are 35 hepatoprotective signaling pathways. GO enrichment analysis revealed that 61 biological processes related to the hepatoprotective effect of S. marianumwere identified, which mainly involved in response to regulation of biological process and immune system process. Silymarin was the major ingredient derived from S. marianum,which exhibited the hepatoprotective effect by reducing the levels of ALT, AST, TC, TG, HDL-C, LDL-C, decreasing protein expressions of IL-6, MAPK1, Caspase 3, p53, VEGFA, increasing protein expression of AKT1. The present study provided new sights and a possible explanation for the molecular mechanisms of S. marianumagainst NAFLD.

Observations of surface displacements are expected to aid in geomechanical analyses of injection-induced seismicity. However, the controlling factors of the displacement magnitude remain poorly understood except the elastic modulus of the fluid-bearing reservoir. Here, an experiment scheme of numerical simulation based on fully-coupled poroelasticity is designed to investigate the displacements induced by deep underground fluid injection. According to the sealing ability of deep reservoirs, the numerical experiments are classified into two scenarios: injection into open and sealed reservoirs. Potential effects from both geological and operational parameters are considered during the experiments, which include the hydromechanical properties, the reservoir geometry, injection rates and volumes. Experimental results reveal that in addition to the reservoir depth and Young's modulus, the porosity also has significant influences on the surface displacements. Geodetic modeling of injection-induced displacements should include the parameter of reservoir porosity. When the reservoir is characterized by a good sealing ability, fluid injection is prone to induce larger horizontal displacements than vertical uplifts. Most of injection activities including hydraulic fracturing can probably induce detectable surface displacements. Geodetic surveying, especially using Global Navigation Satellite System (GNSS) with both horizontal and vertical observations, should become an essential monitoring task for anthropogenic fluid injection/production activities, which is conducive to assess and mitigate some geohazards including earthquakes.

To overcome the high cost of learning, non-visual operation, and cumbersome steps of fine-tuning map elements in Generic Mapping Tools (GMT) and other geoscience mapping softwares, we present the Tectonic Geodesy Application (TGA), a user-friendly 64-bit tectonic geodesy mapping software based on the secondary development interface of the open source geographic information system QGIS. In this paper, we detailly introduce the architecture and function modules of our software, and highlight the functions of rendering and map decoration through four cases: the geologic map of Papua New Guinea, the seismicity in China and surrounding regions, the seismicity and crustal deformation of the Tibetan Plateau and the coseismic deformation of the 2017 Jiuzhaigou earthquake in China. Compared with GMT, the tectonic geodesy mapping software we developed has the advantages of simple operation, low learning cost and user-friendly interface.

The subsurface fluid injection can cause pressure increase within faults, leading to earthquake occurrences. However, the factors controlling earthquake rupture due to pressure perturbation remain poorly understood. To resolve this problem, we simulate the physical processes of earthquake nucleation and rupture on strike-slip faults perturbated by pressure migration based on the slip-weakening law. Multiple kinds of factors, including background stress, fluid injection rates, the area of the pressurized region, fault geometry, and fault friction coefficients, are considered in our simulations. Our simulation results reveal that the ratio of shear stress to normal stress rather than their absolute values controls the rupture behavior. With the large stress ratios, high injection rates, and large pressurized areas, earthquakes are prone to propagate as runaway ruptures. Additionally, faults with large aspect ratios of length to width are also favorable for causing runaway ruptures. In contrast, the factors of fault strike, dip angles and friction coefficients have minor influence on rupture behavior.

The mechanisms of unusual shallow intraplate earthquakes that occasionally occur in stable cratons remain poorly understood. Here we analyze coseismic and postseismic displacement fields associated with the 2016 Petermann Ranges earthquake in central Australia using interferometric synthetic aperture radar data. The earthquake ruptured a previously unmapped fault and was dominated by thrust slip motion of up to 95 cm within the top 3 km of the crust. Postseismic deformation analysis suggests that a combination of poroelastic rebound and afterslip are responsible for the observed signals. The inferred afterslip overlapping spatially with the coseismic rupture highlights that the postseismic slip is coupled with the pore fluid flow around the fault zones. Analysis of historic groundwater‐level changes suggests that shallow seismicity around the Petermann Ranges may have been triggered by environmental stress perturbations due to the fluctuations of groundwater level; however, it is not easy to document statistical significance of this correlation. Shallow surface‐rupturing earthquakes have been observed globally. However, how these events are triggered and why they sometimes occur within stable continents is largely unknown. We carefully study the coseismic and postseismic deformation of a 2016 Mw6 earthquake in central Australia to determine the source parameters and slip distributions. We find the coseismic slip and early afterslip are concentrated at depths shallower than 3 km, and poroelastic rebound substantially contributes to the early period of postseismic deformation. We further investigate potential mechanisms to explain rock failure at such shallow depth and find a possible relationship between the fluctuations of groundwater level and the occurrence of shallow seismicity in the region. The results of this study help shed light on the processes and causes of shallow earthquakes. Coseismic slip of the 2016 Mw6 Petermann Ranges earthquake is concentrated at shallow depths between 0 and 3 kmPostseismic displacements are governed by a combination of poroelastic rebound and afterslipThe occurrence of shallow earthquakes might be caused by groundwater levels changes in central Australia

It is essential to establish simple, sensitive and accurate quantitative approaches for microRNAs (miRNAs) identification due to its crucial roles in a variety of physiological and pathological processes. Herein, we propose a novel RCA-based colorimetric method for sensitive and reliable miRNA analysis. In this approach, cyclization of the padlock sequence by miRNA-21 initiates the RCA to produce numerous G-rich sequences. The generated G-rich sequences fold to G-quadruplex DNAzyme that is capable of catalyzing cysteine to cystine which could mediate the gold nanoparticle-based color reaction, outputting results that can be observed directly by naked eyes. Based on this, the approach exhibits a wide detection range with a low limit of detection of 4 fM. In addition, the dual target recognition endows the method a greatly improved selectivity.

To resolve the occurrence mechanism of the Luxian earthquake occurred near an active hydraulic fracturing well pad on 15 September 2021, we first use seismic waveforms to invert the focal mechanism solution and centroid depth, and then utilize Sentinel‐1 Synthetic Aperture Radar images and Global Navigation Satellite System observations to determine the seismogenic fault and slip distribution. Our results show that the Luxian event ruptured a previously‐unmapped southwest‐dipping reverse fault intersecting with one horizontal well of the well pad. Major slip occurred below the shale gas bed (∼4 km deep) but above the crystalline basement (∼7 km deep). Further analyses on preseismic surface deformation initiated in the northeast of the event reveal that pore pressure near the hypocenter was increased by ∼4.5 MPa. Consequently, fracking fluid injected through the horizontal well and other wells of nearby pads likely flowed directly into the fault zones and prompted the occurrence of the Luxian earthquake. Due to huge casualties and property losses, the Ms 6.0 Luxian earthquake aroused wide public concern. Beyond that, at 0.85 km south of the epicenter, there is a hydraulic fracturing (HF) well pad (H79) that was operating before the earthquake occurrence. Therefore, people suspect that there was some relationship between the event and HF operations. We here jointly use seismic waveforms of regional permanent stations, Sentinel‐1 Synthetic Aperture Radar images, and Global Navigation Satellite System observations to determine the location and 3D geometry of the source fault. We find the fault intersecting with one horizontal well of the nearby pad, indicating that fracking fluid can flow directly into the fault zones and cause pressure perturbation with magnitudes comparable to the minimum principal stress. In addition, we also find preseismic deformation around the epicenter initiated after 29 May 2021. The deformation is likely linked to accumulation of fracking fluid injected during the drilling and HF operations of other pads. Further modeling reveals that the fluid accumulation increased pore pressure by ∼4.5 MPa near the hypocenter. The source fault likely suffered pressure diffusion before the operation of well pad H79 and was eventually reactivated by pressurization directly linked to HF stimulation. The Luxian earthquake ruptured an unmapped south‐dipping reverse fault with major slip occurred in deep sedimentary formationsPreseismic surface deformation analyses indicate that fracking fluid accumulation likely caused pressure increase near the hypocenterThe source fault, intersecting with one horizontal hydraulic fracturing well, was likely reactivated by direct fault‐zone pressurization The Luxian earthquake ruptured an unmapped south‐dipping reverse fault with major slip occurred in deep sedimentary formations Preseismic surface deformation analyses indicate that fracking fluid accumulation likely caused pressure increase near the hypocenter The source fault, intersecting with one horizontal hydraulic fracturing well, was likely reactivated by direct fault‐zone pressurization

Over 1000 earthquakes struck the northwest of Kangding on the Xianshuihe fault in southwest China between 22 and 29 November 2014, including two largest events of Mw5.9 and Mw5.6. The hypocenters of 799 relocated earthquakes suggest that two independent main shock‐aftershock subsequences occurred on the Selaha and Zheduotang branches of the Xianshuihe fault, respectively. Fault slip inversion results from one interferometric synthetic aperture radar (InSAR) interferogram (26 September 2014 to 5 December 2014) show that the Mw5.9 main shock produced a maximum slip of ~0.47 m at the depth of ~9 km. However, there is no distinct slip associated with the Mw5.6 main shock. The InSAR determined moment is 2.36 × 1018Nm with a rigidity of 30 GPa, equivalent to Mw6.2, which is about twofold the total seismic moment of all the recorded earthquakes during the InSAR time span. This large discrepancy between geodetic and seismic moment estimates indicates that there was probably rapid aseismic afterslip in the 2 weeks following the Mw5.9 main shock. The released seismic energy of this earthquake sequence is far less than the accumulated strain energy since the 1955 M712earthquake on the same fault branch, which implies that the seismic risk on the Selaha‐Kangding segment of the Xianshuihe fault remains high. The 2014 Kangding earthquake sequence is double‐shock typeThe Mw5.9 main shock produces distinct coseismic slipThe risk of large earthquake near Kangding is still high

From 2017 to 2019, three destructive earthquakes (27 January 2017 Mw 4.7, 16 December 2018 Mw 5.2, and 3 January 2019 Mw 4.8) occurred in the Changning shale gas field in the southwest Sichuan Basin, China. Previous seismological studies attributed these events to hydraulic fracturing (HF), but were unable to identify the causative seismogenic faults and their slip behaviors. Here, we use Sentinel‐1 synthetic aperture radar data to measure surface deformation triggered by the three events and conduct geodetic inversions to characterize their rupture models. The resulting coseismic interferograms show prominent surface deformation with the maximum line‐of‐sight displacements of up to 4 cm. The inversion results show that all three earthquakes mainly ruptured sedimentary formations above the shale gas bed, in the upper 3 km of the crust, with slip magnitudes ranging from 8.5 to 15 cm, and stress drops ranging from ∼1.8 to ∼3.3 MPa. Their source faults intersect with horizontal HF wells, but do not root in the crystalline basement. Combined with the reported difficulty of increasing HF operation pressures prior to the three events, we argue that they were most likely induced by direct injection of pressurized fluids into the fault zones. Crustal deformation patterns inferred from regional topography and GPS velocities highlight that the Changning field is located within a triple junction region near the southeastern margin of the Tibetan Plateau with large deformation gradients; such conditions are not only favorable to the development of critically stressed faults, but also facilitate the occurrence of at least moderate magnitude earthquakes. The number of earthquakes induced by the process of shale gas extraction through hydraulic fracturing (HF) has been increasing across the globe, with dozens of M> 4 events reported by the end of August 2021. Although most case studies on HF‐induced seismicity are from the United States and Canada, the southwestern Sichuan Basin (China), located to the southeast of the Tibetan Plateau, is another region with notable seismicity linked to HF operations, including dozens of moderate‐to‐large earthquakes. We here focus on the three largest Mw ≥ 4.7 earthquakes that occurred within the Changning shale gas field up to now. We use geodetic techniques to measure ground deformation caused by the three earthquakes and to further infer their ruptures at depth. Our results reveal that the three earthquakes occurred on shallow faults intersecting with horizontal HF wells, with little‐to‐no slip in the crystalline basement below the depth of 3 km. These questions the common theme of HF‐induced earthquakes having hypocenters proximal to basement rock, presumably associated with basement‐rooted faults, and suggests that the potential for ground shaking of HF‐induced earthquakes is more significant than previously understood. The three events ruptured shallow faults within sedimentary formations above the shale gas bed rather than basement‐rooted faultsThe faults of the three events intersect with horizontal hydraulic fracturing wells and were likely reactivated by direct fault‐zone pressurizationHigh HF‐induced seismicity rate in the Changning area links to the proximity to a triple junction region with relatively high tectonic strain accumulation rates The three events ruptured shallow faults within sedimentary formations above the shale gas bed rather than basement‐rooted faults The faults of the three events intersect with horizontal hydraulic fracturing wells and were likely reactivated by direct fault‐zone pressurization High HF‐induced seismicity rate in the Changning area links to the proximity to a triple junction region with relatively high tectonic strain accumulation rates

The world's largest underground gas storage facility in Hutubi (HUGS), China, is a unique case where cyclic gas injection‐extraction induced both seismicity and ground deformation. To assess the potential for future induced seismicity, we develop a framework physically based on a well‐constrained hydro‐geomechanical model and on fully‐coupled poroelastic simulations. We first interpret the spatiotemporal distribution and focal mechanisms of induced earthquakes and take it as a key step and a premise to estimate the magnitude and location of the largest potential earthquake. The sharp increase in seismicity was controlled by poroelastic loading on secondary southwest‐dipping thrust faults with spatial scales too small to be resolved by 3D seismic surveys. Both operational and local geological factors affect the seismic productivity at the HUGS site, distinguishing it from most cases of seismicity induced by wastewater disposal and hydraulic fracturing. We then conduct slip tendency analyses for major faults imaged by the seismic data, including the largest reservoir‐bounding Hutubi fault hydraulically connected to injection wells. The reactivation potentials of these imaged faults are estimated to be extremely low. Accordingly, future seismicity would most likely occur on failure‐prone secondary faults in regions with positive stress perturbation due to poroelastic loading. The maximum magnitude likely depends on the spatial scales of the secondary faults. As the occurrence of detected earthquakes is spatially and temporally consistent with the simulated evolution of Coulomb stress perturbation, the location of the largest potential earthquake probably depends on the sizes of the poroelastic stressing regions. Across the world there are numerous underground gas storage (UGS) facilities that are either under construction or planned due to major demands for clean energy and major concerns over tackling issues related to global climate change. Induced seismicity at UGS facilities is a burgeoning topic, with few documented cases so far. In some cases UGS facilities are located in highly populated regions that could experience strong ground shaking due to local and shallow induced earthquakes. Under the typical scenario of earthquakes induced by pore pressure diffusion, the maximum magnitude is sometimes thought to be governed by fluid‐stimulated rock mass or the volume of injected fluids. However, in the case of earthquakes induced by poroelastic effects (rock deformation beyond the overpressure front), we know very little about the influence of additional critical parameters on the timing, location, and magnitude of induced earthquakes. The largest potential earthquake associated with the HUGS is a problem compounded by the effects from pressure and poroelastic perturbation. Our study helps to fill in the knowledge gap between pore pressure and poroelastic effects, and provides a reference to assess and mitigate the risk of seismicity related to UGS operations. Sharp increase of induced seismicity was primarily controlled by poroelastic loading on secondary southwest‐dipping thrust faultsSlip tendency analyses reveal low reactivation potential of the largest Hutubi fault hydraulically connected to injection wellsThe largest potential event would most likely occur on secondary faults in regions where poroelastic loading promotes frictional failure Sharp increase of induced seismicity was primarily controlled by poroelastic loading on secondary southwest‐dipping thrust faults Slip tendency analyses reveal low reactivation potential of the largest Hutubi fault hydraulically connected to injection wells The largest potential event would most likely occur on secondary faults in regions where poroelastic loading promotes frictional failure

In June 2019, an earthquake sequence comprising five M > 5 events occurred in a region of southwest China with fluid injection for both hydraulic fracturing and salt mining, which raised an extensive controversy on the cause. Here we use interferometric synthetic aperture radar (InSAR) observations to determine the source parameters of the sequence and to investigate the relationship with local injection activities. Both Sentinel‐1 and Advanced Land Observing Satellite 2 SAR images are collected to measure coseismic and preseismic surface deformation. Geodetic inversions with coseismic observations show that the sequence ruptured a previously unmapped southwest‐dipping thrust fault above 3 km depth, which intersects with the open‐hole sections of wells for solution mining of salt. In the 4 months before the sequence, cumulative line‐of‐sight displacements near the wells are around 1–2 cm after correcting seasonal‐like deformation. Our results indicate that water injection likely enhanced pore pressure within the fault zone and thus contributed to inducing the sequence. Earthquakes are seldom reported in relation to fluid injection for salt mining. Here, we present a unique case of an earthquake sequence probably induced by such human activity in Changning (southwest China). The sequence began with a Ms 6.0 earthquake, which is an unprecedented magnitude and larger than the historical records of earthquakes induced by wastewater disposal and hydraulic fracturing. Due to the sparse distribution of seismic stations and the failure of a key station closest to injection wells for salt mining before the Ms 6.0 earthquake, available seismic data are not enough to constrain the spatial locations of events in the earthquake sequence. Here we instead use high spatial‐resolution interferometric synthetic aperture radar observations of coseismic surface deformation to image the causative fault of the sequence. We find that the open‐hole sections of injection wells intersect the seismogenic fault. Moreover, the cumulative surface displacements near the salt mine in the ~4 months before the sequence are 1–2 cm, which was mainly caused by ground uplift. Accordingly, we hypothesize that fluid injection increased pore pressure within the fault zone and brought it to rupture. Our interferometric synthetic aperture radar observations and inversion results present significant evidence toward the causality between salt mining and the earthquake sequence. InSAR observations show significant ground deformation due to the Changning earthquake sequence near the salt mineInSAR inversions reveal that the Changning earthquake sequence ruptured a southwest‐dipping thrust fault above the depth of 3 kmThe open‐hole sections of wells injecting for solution mining of salt intersect the InSAR‐inferred seismogenic fault