Acta Geodaetica et Geophysica最新文献

{"title":"Full gravity gradient tensor modeling by normal gravity field and digital terrain models","authors":"Oleg Odalović,&nbsp;Dejan Vasić,&nbsp;Lajos Völgyesi","doi":"10.1007/s40328-026-00488-3","DOIUrl":"10.1007/s40328-026-00488-3","url":null,"abstract":"<div><p>This paper examines the possibility of modeling Earth’s gravity gradients using only the normal gravity field and the masses located above the reference ellipsoid. The contribution of the ellipsoidal mass was computed based on the normal gravity field and the second derivatives of the normal gravity potential. The remaining part was modeled by discretizing the topographic masses and approximating their gravitational effects using prisms as regular geometric bodies. The practical study was conducted over the territory of Serbia. The computed gradients were compared with torsion balance measurements taken at a test area near Novi Sad. A root mean square value of 17 E (1.7 μGal/m) was obtained for the gradient differences. Gradient values from a global geopotential model were also computed, and it was found that, over extremely flat terrain, they exhibit similar or slightly better agreement with the measurements than the modeled values. The results demonstrate that the proposed concept enables modeling of gravity gradients with an overall deviation that is comparable to the accuracy of the measurements or, at most, within one order of magnitude.</p></div>","PeriodicalId":48965,"journal":{"name":"Acta Geodaetica et Geophysica","volume":"61 1","pages":"119 - 148"},"PeriodicalIF":1.8,"publicationDate":"2026-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147559384","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":"Comparative study of differential evolution (DE) and genetic algorithm (GA) for robust magnetic inversion and subsurface characterization of 2D dipping dykes in engineering geological investigations","authors":"Reza Toushmalani,&nbsp;Yves Géraud,&nbsp;Khalid S. Essa","doi":"10.1007/s40328-026-00487-4","DOIUrl":"10.1007/s40328-026-00487-4","url":null,"abstract":"<div>\u0000 \u0000 <p>This study explores the application and comparative performance of the Differential Evolution (DE) algorithm and the Genetic Algorithm (GA) for interpreting magnetic anomalies caused by 2D dipping dyke-like structures, emphasizing their utility for both mineral exploration and engineering geological investigations. Accurate estimations of dyke parameters (depth, width, dip, magnetization) is critical for: (1) assessing geotechnical stability in construction and tunneling projects; (2) evaluating volcanic and seismic hazards related to dyke propagation; and (3) identifying mineralized zones that impact groundwater flow. The dyke parameters are estimated by minimizing an objective function to achieve an optimal match with observed data. The performance of the DE approach was tested on synthetic magnetic datasets under various noise conditions (0%, 5%, 10%, 15%, and 20%). The approach was further validated using real-world magnetic datasets from Gansu Province, China. A comparative analysis with the Genetic Algorithm (GA) demonstrates that DE offers superior efficiency and reliability, particularly in high-noise scenarios. The inversion results align well with geological and geophysical constraints derived from borehole data, confirming the effectiveness of DE for subsurface characterization. This approach enhances site investigation accuracy and infrastructure planning, offering a robust tool for geotechnical and environmental assessments.</p>\u0000 </div>","PeriodicalId":48965,"journal":{"name":"Acta Geodaetica et Geophysica","volume":"61 1","pages":"103 - 117"},"PeriodicalIF":1.8,"publicationDate":"2026-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147559412","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":"Geophysical investigation of the Antalya Magnetic Anomaly representing the westernmost link of a buried magmatic arc in the Eastern Mediterranean Sea","authors":"Ezgi Erbek-Kiran,&nbsp;Attila Aydemir,&nbsp;Abdullah Ates,&nbsp;M. Nuri Dolmaz","doi":"10.1007/s40328-026-00483-8","DOIUrl":"10.1007/s40328-026-00483-8","url":null,"abstract":"<div>\u0000 \u0000 <p>There is a large magnetic anomaly in the Gulf of Antalya (GoA), in southern Turkey which is the westernmost link of a magnetic anomaly chain in the Mediterranean Sea. It is a buried magmatic arc originating from the subduction in the Eastern Mediterranean region after Eocene. Because this is the first study on the chain, investigation of the anomaly in the GoA will stimulate many multidisciplinary studies on the other causative intrusions in this arc. The main purpose of this study is to provide a methodology for the search of each link while investigating the properties of the causative body in the GoA. Potential field techniques (such as power spectrum analysis, Reduction to Pole-RTP, pseudogravity transformation and 3D modelling) were applied to the GoA anomaly and their maps were constructed. The causative body has a conical shape with two peaks. The top depth of the structure was calculated as 2.6 km while the basement depth was approximately 12 km. The correlation between the marine seismic section crossing this anomaly and magnetic data analysis provides a good consistency. Therefore, this investigation provides valuable insights into the deep structure of the Gulf of Antalya because the relationship between the igneous emplacements and magnetic responses indicates good correlations in the Eastern Mediterranean region.</p>\u0000 </div>","PeriodicalId":48965,"journal":{"name":"Acta Geodaetica et Geophysica","volume":"61 1","pages":"37 - 60"},"PeriodicalIF":1.8,"publicationDate":"2026-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147561035","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":"Geophysical modeling of airborne time domain electromagnetic and potential field magnetic and gravity data to image a polymetallic deposit in Canada","authors":"Ali Jafarabadi,&nbsp;Maysam Abedi,&nbsp;Ali Moradzadeh","doi":"10.1007/s40328-026-00485-6","DOIUrl":"10.1007/s40328-026-00485-6","url":null,"abstract":"<div><p>This study presents a comprehensive geophysical methodology aimed at identifying subsurface alteration zones and mineralization linked to the Bell porphyry copper-gold deposit situated in British Columbia, Canada. The study involved the acquisition and separate inversion of airborne magnetic, gravity, and time-domain electromagnetic (TDEM) datasets. These inversions produced three distinct models representing magnetic susceptibility, density contrast, and electrical conductivity. Interpretation of these models has revealed spatially distinct physical property anomalies corresponding to potassic, phyllic, and propylitic alteration zones typical of porphyry systems. Notably, the potassic zones were identified by their elevated susceptibility and density, while the phyllic zones demonstrated significant conductivity attributed to the presence of disseminated sulfides. In contrast, the propylitic zones exhibited moderate responses across all datasets. By synthesizing these geophysical findings with existing geological knowledge, a two-dimensional conceptual geological section was developed, effectively correlating alteration zonation with the identified geophysical anomalies. This integrated approach highlights the efficacy of multi-parameter airborne geophysics in refining subsurface characterization for mineral exploration. The resulting geological model not only offers profound insights into the structural aspects of the deposit but also serves as a strategic tool for directing future exploration efforts within the region.</p></div>","PeriodicalId":48965,"journal":{"name":"Acta Geodaetica et Geophysica","volume":"61 1","pages":"61 - 80"},"PeriodicalIF":1.8,"publicationDate":"2026-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147558773","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 inversion for magnetotelluric data based on cuckoo search algorithm and least squares method","authors":"Ruiyou Li,&nbsp;Rongqiang Liu,&nbsp;Long Zhang,&nbsp;Yong Zhang,&nbsp;Xiaohui Ding,&nbsp;Min Li","doi":"10.1007/s40328-026-00486-5","DOIUrl":"10.1007/s40328-026-00486-5","url":null,"abstract":"<div><p>The main drawback of using traditional linear or quasi-linear methods for magnetotelluric (MT) data inversion is its strong dependence on the initial model, which leads to its tendency to fall into a local optimum. However, the lack of sufficient a priori information makes it difficult to obtain suitable initial models in most geophysical inversions. To solve this problem, a hybrid approach (CS-MLS) based on the cuckoo search (CS) algorithm and the moving least squares (MLS) method is proposed to perform MT data inversion. The CS algorithm has a good global search performance without being sensitive to the initial model, which is used for the initial search of the stratum model parameter space. The search results are then used as the initial model to explore the quasi-linear inversion based on MLS. The synthetic and field data experiments show that the reliable initial model provided by the CS algorithm has greatly refined the results of the MLS inversion. The hybrid CS-MLS algorithm has great inversion performance, with significant improvement in inversion efficiency and accuracy, and is especially suitable for MT data inversion without initial information.</p></div>","PeriodicalId":48965,"journal":{"name":"Acta Geodaetica et Geophysica","volume":"61 1","pages":"81 - 101"},"PeriodicalIF":1.8,"publicationDate":"2026-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147559589","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":"Seismotectonic features of the Southern Carpathians, Romania, resulted from focal mechanism inversion","authors":"A. Bălă,&nbsp;M. Radulian,&nbsp;M. Popa,&nbsp;C. Gheablău","doi":"10.1007/s40328-025-00481-2","DOIUrl":"10.1007/s40328-025-00481-2","url":null,"abstract":"<div><p>The study area is located in the western branch of the Southern Carpathians in Romania, between the Olt River and the Danube. The data on seismicity recorded before 1999–2000 indicate a sporadic seismic activity, mostly of small magnitude. A few events of magnitude above 5 (maximum magnitude Mw 5.7) have been reported through historical data, which are inherently imprecise. Recently, several significant crustal sequences occurred in the region in 2011–2012 (eastern part of Târgu Jiu city), 2011 and 2013 (Haţeg basin), 2014–2015 (Caransebeş–Mehadia basin), 2020 (Orşova basin). The most spectacular sequence was recorded at the contact between Southern Carpathians and Getic depression, in the northern part of Târgu Jiu city, starting in February with two shocks of magnitude above 5, and continuing for more than one year with more than 4000 aftershocks. The new recorded data are particularly valuable for interpreting the present-day seismotectonics and for redefining the regional seismic hazard. The motivation of the present study naturally came out from the need to elucidate what makes the regional tectonics able to suddenly activate an unexpected level of seismicity for an area previously characterized by apparently sporadic and insignificant seismic activity. In order to characterize the stress field, we collected all the earthquake focal mechanisms available from source catalogues that we considered to be of acceptable quality. For inversion, we defined 8 individualized clusters of earthquakes associated either to active tectonic faults, or to intramontane extensional basins, for which we assumed that the individual focal mechanisms follow the trends of a homogeneous stress field. The results show a clear model of mostly extensional stress field responsible for generating the earthquake swarms during the last decades. The configuration of the horizontal stress directions reveals a complex tectonic setting following a main NE-SW trending associated with the transcurrent movement along the active faults in the Danubian region (e.g., Cerna–Jiu fault, Timok fault) and significant rotations toward a NW-SE alignment in the intramontane basins and in the Getic depression. It reveals an overall extensional stress field predominance in the Southern Carpathians.</p></div>","PeriodicalId":48965,"journal":{"name":"Acta Geodaetica et Geophysica","volume":"61 1","pages":"1 - 36"},"PeriodicalIF":1.8,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147558778","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":"Achieving PPP instantaneous convergence with the integration of GLONASS/GPS/BDS-3/Galileo triple-frequency observations","authors":"Fan Zhang,&nbsp;Wei Lu,&nbsp;Fan Gao,&nbsp;Linlu Gan,&nbsp;Tao Liu","doi":"10.1007/s40328-025-00479-w","DOIUrl":"10.1007/s40328-025-00479-w","url":null,"abstract":"<div><p>Currently, four dominant Global Navigation Satellite Systems (GNSS), namely GPS (G), Galileo (E), GLONASS (R), and BDS-3 (C), provide multi-frequency positioning services on a global scale. To fully harness the potential of multi-system and multi-frequency signals for precise point positioning (PPP), a triple-frequency PPP ambiguity resolution (PPP-AR) model by integrating observations from GLONASS, GPS, Galileo, and BDS-3 is presented for the first time. Particular attention was given to incorporating newly available signals, such as GLONASS code-division multiple-access (CDMA) L3 and BDS-3 B2a, into the proposed GERC triple-frequency PPP-AR framework to realize instantaneous convergence. To address the challenges posed by GLONASS inter-frequency biases (IFBs) inherent to its frequency-division multiple-access (FDMA) strategy, we introduced an uncalibrated phase delay (UPD) estimation method based on homogeneous receiver networks. Additionally, inter-frequency clock biases (IFCBs) across multiple systems were comprehensively determined and calibrated within the GERC triple-frequency PPP-AR context. To validate the proposed model, observational datasets from 20 EUREF Permanent Network (EPN) tracking stations equipped with identical JAVAD receivers were processed. The quality of UPD estimates was evaluated through residual distribution analysis, revealing a strong correlation between UPD correction accuracy and the magnitude of residuals. Results showed that nearly 100% of extra-wide lane (EWL) ambiguity residuals for each GNSS constellation were within 0.15 cycles. Furthermore, more than 95% of wide lane (WL) and narrow lane (NL) ambiguity residuals were below 0.25 cycles. Statistical analysis demonstrated that the GERC triple-frequency PPP-AR achieved an instantaneous convergence time of approximately 0.71 min, significantly outperforming single-system PPP-AR solutions such as G (7.32 min), GR (4.95 min), GC (3.10 min), and GE (1.39 min). Compared to the dual-frequency GERC PPP-AR (1.82 min), the triple-frequency solution improved convergence time by approximately 61%. These results are highly encouraging, as they demonstrate that multi-GNSS PPP-AR solutions can achieve sub-minute convergence times with enhanced positioning accuracy. In addition, simulated kinematic PPP-AR experiments further confirmed the superiority of the GERC triple-frequency scheme. The convergence time was reduced to approximately 3.43 min, significantly outperforming the triple-frequency GEC scheme (4.68 min) and the dual-frequency GERC scheme (5.25 min). The incorporation of GLONASS L3 observations proved vital for enhancing PPP-AR performance.</p></div>","PeriodicalId":48965,"journal":{"name":"Acta Geodaetica et Geophysica","volume":"61 1","pages":"149 - 176"},"PeriodicalIF":1.8,"publicationDate":"2025-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147561029","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":"An approach for improving the accuracy of global geopotential models over a local region: a case study in the Nile Delta, Egypt","authors":"Gomaa Dawod,&nbsp;Alshimaa A. Hussien","doi":"10.1007/s40328-025-00478-x","DOIUrl":"10.1007/s40328-025-00478-x","url":null,"abstract":"<div><p>Adding local, precise geodetic datasets is necessary to improve the accuracy and performance of Global Geopotential Models (GGMs). Consequently, GGMs could be utilized in geosciences, geodetic, and geomatics applications, particularly in developing countries where no accurate geoid model is affordable. Typically, the discrepancies of geoid undulations at Global Navigation Satellite Systems (GNSS)/Levelling stations are utilized to establish a correction surface within a Geographic Information Systems (GIS) environment. The current research proposes a new approach that depends on taking into account both GGM errors in geoidal undulations and free-air gravity anomalies over a particular local region. This method has been carried out in the Nile Delta region, north of Egypt, utilizing 160 GNSS/Levelling stations and 20 terrestrial gravity points. Two GGM models have been investigated as candidates for high-resolution global models, namely the EGM 2008 and the SGG-UGM-2 models. The accomplished results showed that the traditional approach enhances the EGM2008 by 21% while the proposed weighted approach yields 45% improvements. Less enhancement has been reported for the SGG-UGM-2 model. The proposed approach does not require more local datasets and consequently no more economic costs are needed. Moreover, the processing methodology of that approach is quite straightforward, which means that it could be performed in other developing countries to enhance the performance of GGMs.</p></div>","PeriodicalId":48965,"journal":{"name":"Acta Geodaetica et Geophysica","volume":"60 4","pages":"451 - 463"},"PeriodicalIF":1.8,"publicationDate":"2025-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145808740","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":"Gravitational field modeling of irregularly shaped bodies by solving the coupled interior-exterior boundary value problem","authors":"Marek Macák,&nbsp;Zuzana Minarechová,&nbsp;Karol Mikula","doi":"10.1007/s40328-025-00480-3","DOIUrl":"10.1007/s40328-025-00480-3","url":null,"abstract":"<div><p>In this paper, we propose and apply a novel numerical approach for modeling the gravitational field by solving the coupled interior-exterior boundary value problem (BVP) using the finite element method (FEM). To this end, we construct a finite computational domain encompassing the selected celestial object and a bounded portion of its exterior, within which the BVP is formulated. This problem consists of the Poisson equation for the gravitational potential, along with a Dirichlet boundary condition (BC) prescribed on the boundary. In this case, since the boundary is placed far from the object so that the Dirichlet BC is nearly zero, the only key input for the computation is the 3D model of the celestial body and its density. The solution is derived using the FEM, which is particularly effective for handling highly irregular or complex surface geometries. The numerical experiments include a test case involving a homogeneous sphere to demonstrate the second-order accuracy of the proposed approach as well as simulations of the gravitational fields of two selected asteroids, namely 25143 Itokawa and 433 Eros, and the comet 67P/Churyumov-Gerasimenko. These simulations yield detailed three-dimensional distributions of both gravitational potential and gravitational acceleration within the entire computational domain.</p></div>","PeriodicalId":48965,"journal":{"name":"Acta Geodaetica et Geophysica","volume":"60 4","pages":"465 - 480"},"PeriodicalIF":1.8,"publicationDate":"2025-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145808738","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":"Experimental investigation on the permeability evolution and mechanism of burnt rock under fluid–solid coupling conditions","authors":"Ankun Luo,&nbsp;Shuning Dong,&nbsp;Hao Wang,&nbsp;Xiaoming Guo,&nbsp;Zhongkui Ji,&nbsp;Tiantian Wang,&nbsp;Hongbo Shang,&nbsp;Xiaoyu Hu,&nbsp;Yuan Liang,&nbsp;Zhennan Zhu","doi":"10.1007/s40328-025-00477-y","DOIUrl":"10.1007/s40328-025-00477-y","url":null,"abstract":"<div><p>Water inrush is the second greatest threat among the most frequent accidents associated with mine production. To address the changes in permeability and stability in the burnt area of the Shennan mining area, in this study, triaxial compressive and permeability tests were conducted on burnt rocks with whose acoustic emission (AE) characteristics were collected. Further analysis was conducted on the correlation among the strength properties, permeability evolution and AE characteristics of the burnt rocks under fluid–solid coupling conditions to reveal the permeability evolution of the burnt rocks. The testing results indicate that the four stages of permeability changes are related to different regions of the stress-strain curves. The AE damage variable begins to increase, and the effects of cracks on permeability, stress-strain curves, and AE ringing counts gradually increase with the development of cracks. The permeability increases rapidly in near the initiation stress (<i>σ</i>_<i>ci</i>), revealing that crack initiation and growth induce an increase in the permeability of the burnt rock. Specifically, the permeabilities of the burnt rock at yield stress (<i>σ</i>_<i>cd</i>) are 3.24, 3.21 and 3.04 larger than these at initiation stress (<i>σ</i>_<i>ci</i>) with the confining stresses of 2, 5 and 8 MPa. Consequently, monitoring the stress and AE signals of burnt rock masses with mining stress disturbances and preventing and controlling water inrush risk in the hidden burnt rock area in the Ningtiaota coal mine of the Shennan mining area are important.</p><h3>Graphical abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":48965,"journal":{"name":"Acta Geodaetica et Geophysica","volume":"60 4","pages":"425 - 449"},"PeriodicalIF":1.8,"publicationDate":"2025-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145808739","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}