pure and applied geophysics最新文献

{"title":"Co-seismic Static Stress Field and Stress Triggering of Aftershocks in the 2022 Menyuan Ms 6.9 Earthquake","authors":"Jialu Liu,&nbsp;Zhitong Jin,&nbsp;Huafeng Sun,&nbsp;Yongge Wan","doi":"10.1007/s00024-024-03584-z","DOIUrl":"10.1007/s00024-024-03584-z","url":null,"abstract":"<div><p>This study investigates the impact of the magnitude 6.9 Menyuan earthquake in Qinghai, 2022, on surrounding areas using the elastic half-space dislocation model. It calculates the co-seismic displacement and stress fields of the Menyuan earthquake and examines the mainshock's triggering effect on aftershocks based on co-seismic Coulomb stress changes. The results show: (1) The materials converge from the southwest and northeast before dispersing from the northwest and southeast around the epicenter, with subsidence in the southwest and northeast and uplift in the northwest and southeast. (2) Stress-wise, expansion occurs southwest and northeast, while compression occurs northwest and southeast of the epicenter. (3) The Coulomb stress change displays positive and negative areas. At a depth of 5 km, the aftershock triggering ratio of magnitude 3 and above is 33.33%, while at depths of 10 km and 15 km, the aftershock triggering ratio is 100%. (4) The overall pattern of distribution of Coulomb stress variations remains consistent across the different rupture models and different depths, but the distribution in the near-field close to the fault is quite significantly different. Furthermore, the differences in overall stress distribution patterns produced by changes in crustal velocity models and friction coefficients are relatively small compared to those caused by changes in rupture models, although specific numerical discrepancies can occur at certain points.</p></div>","PeriodicalId":21078,"journal":{"name":"pure and applied geophysics","volume":"181 10","pages":"3019 - 3035"},"PeriodicalIF":1.9,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142753970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Machine Learning-Based SST Retrieval from Thermal Infrared Observations of INSAT-3D Imager: Improvement Over Regression-Based NLSST Algorithm","authors":"Rishi Kumar Gangwar,&nbsp;M. Jishad,&nbsp;P. K. Thapliyal","doi":"10.1007/s00024-024-03586-x","DOIUrl":"10.1007/s00024-024-03586-x","url":null,"abstract":"<div><p>Sea surface temperature (SST) is one of the key Essential Climate Variables for studying and monitoring Earth’s climate, besides playing an important role in physical oceanographic processes and as a boundary condition in the numerical prediction models. Understanding these processes requires the availability of accurate and consistent SST products over the global ocean, which can be fulfilled by retrieving them from satellite-based observations. Therefore, the present study exploits a supervised machine learning technique, Deep Neural Network (DNN), for the retrieval of SST using thermal infrared (TIR) split-window observations from Imager onboard India’s geostationary satellite, INSAT-3D, which was launched in 2013. A matchup dataset is prepared to train and test the DNN, comprising the collocated brightness temperatures of TIR channels of INSAT-3D Imager with the in-situ SST measurements for 2017–2020. The DNN-based algorithm exhibits a similar statistics with reference to the in-situ SST for both training and testing datasets. It is further assessed on independent INSAT-3D observations for May 2021- February 2022 to demonstrate its robustness. Moreover, the performance of the DNN is also compared to the widely used regression-based non-linear SST (NLSST) algorithm, which is presently operational for INSAT-3D. Validation against the in-situ SST shows an improvement of about 37.5% in the accuracy of SST retrieved using DNN (RMSE = 0.5 K) over the NLSST (RMSE = 0.8 K) algorithms for INSAT-3D Imager.</p></div>","PeriodicalId":21078,"journal":{"name":"pure and applied geophysics","volume":"181 12","pages":"3653 - 3665"},"PeriodicalIF":1.9,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142890079","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Depth–Strength In-Situ Stress Model for Granite in Southeastern Tibetan Plateau and Its Implications for Stress Estimation in the Upper Crust","authors":"Junshan Xu,&nbsp;Xiwei Xu","doi":"10.1007/s00024-024-03591-0","DOIUrl":"10.1007/s00024-024-03591-0","url":null,"abstract":"<div><p>Extracting the effective information of a tectonic stress field from in-situ stress data is significantly important for engineering projects and solid Earth sciences but extremely difficult to perform because of the scattered distribution of stress data and the complexity of rock mechanical properties. A depth–strength in-situ stress model is proposed in this study by deriving the local maximum horizontal strain (<i>ε</i>_<i>H</i>) via an analysis of the depth trend of the maximum horizontal principal stress (<i>S</i>_<i>H</i>) for granite in the southeastern Tibetan Plateau (SETP). In this model, the depth trend of <i>S</i>_<i>H</i> is divided into three segments in accordance with the values of <i>S</i>_<i>H</i> and the variations in rock mechanical properties. The first segment (0–15 MPa) shows the complexity of <i>S</i>_<i>H</i> affected by multiple factors of local settings on the near-surface. The second segment (15–45 MPa) exhibits the slope of <i>S</i>_<i>H</i> against depth mainly caused by elastic variations against the decrease in porosity (or fracture closure) and increase in pressure. The third segment (&gt; 45 MPa) explains the stable depth trend of <i>S</i>_<i>H</i> in relation to the increase in pressure only. The <i>ε</i>_<i>H</i> can be extracted using the second segment, and it is in the range of 4 × 10⁻⁴–6 × 10⁻⁴ in the granite area of the SETP. The depth trend of stress in the shallow layer of the crust calculated based on the extracted <i>ε</i>_<i>H</i> is consistent with that from in-situ stress measurements. Moreover, the stress distribution along the Xianshuihe fault calculated based on the extracted <i>ε</i>_<i>H</i> suggests that the values of differential stress range within 200–250 MPa at a depth range of 10–16 km, a result that agrees well with local focal depths. The proposed model connects the in-situ stress in the shallow layers with the tectonic stress environment in the deep crust.</p></div>","PeriodicalId":21078,"journal":{"name":"pure and applied geophysics","volume":"181 10","pages":"3103 - 3120"},"PeriodicalIF":1.9,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142754288","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluating the Accuracy of Machine Learning, Deep Learning and Hybrid Algorithms for Flood Routing Calculations","authors":"Metin Sarıgöl","doi":"10.1007/s00024-024-03575-0","DOIUrl":"10.1007/s00024-024-03575-0","url":null,"abstract":"<div><p>The increase in average temperatures in the last century has caused global warming, which has increased the frequency of natural disasters. Floods are one of the most important natural disasters and harm the environment and especially human life. Flood routing techniques also play an important role in predicting floods. For this reason, the accuracy and precision of flood routing calculations are of vital importance in taking all necessary precautions before the floods reach the region and in preventing loss of life. This study aims to compare the performance of machine learning, deep learning and hybrid algorithms for flood routing prediction models in the Büyük Menderes River. In this research deep learning model Long-Short Term Memory (LSTM), machine learning model Artificial Neural Network (ANN), and hybrid machine learning models empirical mode decomposition (EMD)-ANN, and particle swarm optimization (PSO)-ANN algorithms were compared to forecast the flood routing results in two discharge observation stations in the Büyük Menderes river. The analysis results of the established ML algorithms were compared with statistical criteria such as mean error, mean absolute error, root mean square error and coefficient of determination. Additionally, Taylor diagrams, box plots, and beeswarm plot visual graphs were also used in this comparison analysis. At the end of the research, it was determined that the hybrid algorithm PSO-ANN was the most successful algorithm in forecasting flood routing results among other models according to the error values of MAE: 0.2514, MSE: 0.4613, RMSE: 0.6791, NSE: 0.941 and MBE: 0.047. Moreover, the LSTM algorithm was the approach with second estimation accuracy. The findings are vital in terms of taking necessary precautions and gaining time before floods reach any region.</p></div>","PeriodicalId":21078,"journal":{"name":"pure and applied geophysics","volume":"181 12","pages":"3485 - 3506"},"PeriodicalIF":1.9,"publicationDate":"2024-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142889845","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hybrid Approach for the Time-Dependent Fractional Advection–Diffusion Equation Using Conformable Derivatives","authors":"André Soledade,&nbsp;Antônio José da Silva Neto,&nbsp;Davidson Martins Moreira","doi":"10.1007/s00024-024-03580-3","DOIUrl":"10.1007/s00024-024-03580-3","url":null,"abstract":"<div><p>Nowadays, several applications in engineering and science are considering fractional partial differential equations. However, this type of equation presents new challenges to obtaining analytical solutions, since most existing techniques have been developed for integer order differential equations. In this sense, this work aims to investigate the potential of fractional derivatives in the mathematical modeling of the dispersion of atmospheric pollutants by obtaining a semi-analytical solution of the time-dependent fractional, two-dimensional advection–diffusion equation. To reach this goal, the GILTT (Generalized Integral Laplace Transform Technique) and conformal derivative methods were combined, taking fractional parameters in the transient and longitudinal advective terms. This procedure allows the anomalous behavior in the dispersion process to be considered, resulting in a new methodology called α-GILTT. A statistical comparison between the traditional Copenhagen experiment dataset (moderately unstable) with the simulations from the model showed little influence on the fractional parameters under lower fractionality conditions. However, the sensitivity tests with the fractional parameters allow us to conclude that they effectively influence the dispersion of pollutants in the atmosphere, suggesting dependence on atmospheric stability.</p></div>","PeriodicalId":21078,"journal":{"name":"pure and applied geophysics","volume":"181 11","pages":"3279 - 3297"},"PeriodicalIF":1.9,"publicationDate":"2024-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142889846","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A mathematical model for a buried source in the layered reduced micropolar half-space","authors":"Mohammad Atif,&nbsp;S. T. G. Raghukanth,&nbsp;S. R. Manam","doi":"10.1007/s00024-024-03571-4","DOIUrl":"10.1007/s00024-024-03571-4","url":null,"abstract":"<div><p>The dependency of rotations on translations in the classical elastic theory and the mismatched experimental rotations to the theoretical one leads to the exploration of the reduced micropolar theory. A mathematical model is presented for the response of a layered reduced micropolar half-space subjected to a seismic buried source. In this study, the Cartesian coordinate system is used to derive the proposed formulation, which is helpful to understand the effect of extended seismic sources. In the sequel, full space solutions are derived subjected to impulsive seismic moment tensor in the reduced micropolar medium. The numerical results for the multilayered medium are presented for the point sources, and obtained rotations in the layered reduced micropolar half-space (L-RMHS) are high from the layered elastic half-space (L-EHS). The response in homogeneous reduced micropolar half-space (H-RMHS) is comparatively low compared to the L-RMHS for point sources and as well for finite-fault. The rotational faulting effect is found to be negligible in the far-field region.</p></div>","PeriodicalId":21078,"journal":{"name":"pure and applied geophysics","volume":"181 12","pages":"3507 - 3538"},"PeriodicalIF":1.9,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142889604","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Markov Chain Monte Carlo Solution of the Implicit Nonlinear Inverse Problem with Application to Curve Fitting and Filter Estimation","authors":"William Menke","doi":"10.1007/s00024-024-03581-2","DOIUrl":"10.1007/s00024-024-03581-2","url":null,"abstract":"<div><p>We adapt the Metropolis–Hastings (MH) algorithm to facilitate construction of the ensemble solution of the nonlinear implicit inverse problem. The solution variable is the aggregation of the parameters of interest (model parameters) and the data. The prior probability density function (pdf) is the possibly-non-Normal joint pdf of the prior model parameters and the noisy data, and is defined in a high-dimensional space. The posterior pdf of the solution (estimated model parameter and predicted data) is the prior pdf evaluated on the lower-dimensional manifold defined by the theory. We adapt the MH algorithm to ensure that successors always satisfy the theory (that is, are on the manifold) and provide a rule for computing the probability of a given successor. Key parts of this adaption are the use of singular value decomposition to identify subspaces tangent to the manifold, and orthogonal projection, to move a preliminary estimate of a successor onto the manifold. We apply the adapted methodology to three exemplary problems: fitting a straight line to (x,y) data, when both x and y have measurement noise; fitting a circle to noisy (x,y) data, and finding a filter that takes one noisy time series into another. In these cases, the scatter of the ensemble solution about the linearized maximum likelihood solution is roughly consistent with the linearized posterior covariance, but with some non-Normal behavior. We demonstrate the usefulness of the ensemble solutions by computing empirical pdfs of several informative statistical parameters, the calculation of which would be difficult by traditional means.</p></div>","PeriodicalId":21078,"journal":{"name":"pure and applied geophysics","volume":"181 11","pages":"3299 - 3312"},"PeriodicalIF":1.9,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142889804","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Present–day and future lightning frequency as simulated by four CMIP6 models","authors":"Vladimir V. Guryanov,&nbsp;Roman P. Mikhailov,&nbsp;Alexey V. Eliseev","doi":"10.1007/s00024-024-03587-w","DOIUrl":"10.1007/s00024-024-03587-w","url":null,"abstract":"<div><p>The lightning flash frequency (LFF, also referred to as lightning flash rate) in four models from the Coupled Models Intercomparison Project, phase 6 is examined. For the present day (PD, 1995–2014), the models exhibit very divergent simulation of LFF in terms of multi–annual averages, interannual variability, and temperature sensitivity. The global mean multi–annual average flash frequency differs by a factor of two between the models, and only two of four models are within the reasonable distance from the LIS/OTD (Lightning Imaging Sensor/Optical Transient Detector) satellite retrievals. The model–data and inter–model differences are even more pronounced at a regional scale and during northern summer. CMIP6 simulations show a general increase in lightning flash frequency from the present day to the late 21st century, especially for the simulations with higher anthropogenic <span>(textrm{CO}_2)</span> emissions into the atmosphere. LFF sensitivity coefficient <span>(beta)</span>, which is based on differences between PD and the late 21st century are positive over most continental areas with typical values from 10 to <span>(20 {% , textrm{K}^{-1}})</span> for annual mean LFF and from 20 to <span>(60 {% , textrm{K}^{-1}})</span> for JJA averages over the northern extra–tropical continents (and even up to <span>(100 {% , textrm{K}^{-1}})</span> in some regions for individual models). At the global scale and for annual averages, this sensitivity is from 5 to <span>(17 {% , textrm{K}^{-1}})</span>. In addition, this sensitivity is markedly different from its counterpart derived from the regression of LFF on surface air temperature for PD period. The latter counterpart is negative at the global scale and changes sign between different regions (i.e, it is positive over the North America south–east and is negative over the south–western part of North America and over the India Peninsula). These regional peculiarities are reasonably simulated by the models.</p></div>","PeriodicalId":21078,"journal":{"name":"pure and applied geophysics","volume":"181 11","pages":"3351 - 3374"},"PeriodicalIF":1.9,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142890418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of the Depth of Shallow Workings on the Probability of Sinkhole Formation and Determination of the Contribution of Mines to the Resulting Risk","authors":"Piotr Strzałkowski","doi":"10.1007/s00024-024-03583-0","DOIUrl":"10.1007/s00024-024-03583-0","url":null,"abstract":"<div><p>This paper presents a broad spectrum of factors that have an impact on the environment once underground mines have been closed, with particular emphasis on hard coal mines. Based on the review of scientific literature and own experience, several types of environmental impacts of closed mines were specified. In the author’s opinion, sinkholes pose the most serious hazard to post-mining areas. A high degree of urbanisation of the Upper Silesian Coal Basin and a wide range of mining operations conducted in the past necessitate the post-mining areas development for construction purposes. However, investing in these areas cannot carry risks and pose a threat to public safety. Therefore, a simplified method of determining the probability of sinkhole formation depending on the depth of a shallow void (excavation) in the rock mass was proposed. An algorithm has also been proposed for determining the contribution of individual mining companies to causing sinkhole hazard, which is of great importance in legal proceedings.</p></div>","PeriodicalId":21078,"journal":{"name":"pure and applied geophysics","volume":"181 10","pages":"3121 - 3131"},"PeriodicalIF":1.9,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00024-024-03583-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142753982","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seismogenic Structure and Stress State Associated with the 2023 Jishishan Earthquake, NE Tibetan Plateau","authors":"Yihai Yang,&nbsp;Qian Hua,&nbsp;Xuemei Zhang,&nbsp;Xiaofei Han,&nbsp;Chong Cao,&nbsp;Yurong Qiu","doi":"10.1007/s00024-024-03582-1","DOIUrl":"10.1007/s00024-024-03582-1","url":null,"abstract":"<div><p>On December 18, 2023, an M6.2 earthquake shock the Jishishan County (JSSEQ) in the NE Tibetan plateau. In this study, we conducted a comprehensive analysis based on focal mechanism, seismic b-value and local S-wave splitting analysis to investigate the seismogenic structure and stress state associated with the JSSEQ. The focal mechanism solution shows that the JSSEQ occurs at a centroid depth of 13 km and is associated with a node plane dipping to NNE and the other node plane dipping to WSW. The JSSEQ and its aftershocks are dominated by thrust faulting under prominently sub-horizontal WSW-ENE compression, consistent with the regional stress field. We also observe the JSSEQ occurred in the periphery of a low b-value anomaly body and a ~ 2 year decrease of b-value surrounding the mainshock before the occurrence of JSSEQ. The fast directions are sub-parallel to the maximum horizontal compressive stress with an anticlockwise rotation to the north of the Daotanghe-Linxia fault. Combined with the InSAR observation and surface geology, we deduce that the JSSEQ occurred on a highly stressed asperity of a blind NNE-dipping seismogenic fault, under the control of northeastward expansion of the Tibetan plateau. Our results provide important information for understanding the seismogenic structure and dynamic background of this earthquake that occurred in a highly concerned region.</p></div>","PeriodicalId":21078,"journal":{"name":"pure and applied geophysics","volume":"181 10","pages":"3037 - 3049"},"PeriodicalIF":1.9,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00024-024-03582-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142753949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}