Acta Geophysica最新文献

{"title":"Geophysical attribute-driven Hamiltonian eigenanalysis for reservoir attenuation gradient estimation","authors":"Haitao Yan,&nbsp;Dan Li,&nbsp;Nanke Wu,&nbsp;Wei Zhou","doi":"10.1007/s11600-026-02011-2","DOIUrl":"10.1007/s11600-026-02011-2","url":null,"abstract":"<div><p>Seismic attenuation gradient estimation is a critical yet challenging task in hydrocarbon reservoir characterization, as it directly reflects subsurface lithology and fluid saturation. Traditional methods rely on empirical relationships or simplified physical models that do not adequately capture complex wave propagation in heterogeneous media. We present an attribute-driven extension of the quantum-mechanics-inspired absorption method of Xue et al. (2023) for seismic attenuation gradient estimation. Instead of constructing the Hamiltonian potential field from the raw seismic amplitude, our method derives two complementary hydrocarbon-sensitive attributes—the instantaneous envelope and the S-transform-based instantaneous centroid frequency—that are fused and regularized through anisotropic Gaussian smoothing to form an effective potential field. A discrete Hamiltonian is constructed as a finite-difference discretization of the time-independent Schrödinger equation, and its dominant eigenfunctions serve as an orthonormal, data-adaptive basis. Projecting the trace onto these eigenstates and fitting the local log-spectral decay slope via a Morlet continuous wavelet transform yields a per-sample attenuation gradient, which is synthesized across eigenstates by an energy-weighted average. Tests on two synthetic models with known Q fields and on a 2-D post-stack line from the South China Sea, evaluated through RMSE, SSIM, layer-localization error, and well-log Pearson’s correlation, demonstrate improved localization accuracy and noise robustness relative to conventional time–frequency methods and the amplitude-driven baseline of Xue et al. (2023). The method extends quantum-mechanics-inspired signal representation to multi-attribute geophysical fusion.</p></div>","PeriodicalId":6988,"journal":{"name":"Acta Geophysica","volume":"74 5","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148926797","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":"Coupling WRF with HEC-HMS for streamflow forecasting in typical mountainous catchments of northwestern Iran","authors":"Sajad Akbari Moghaddam Sani,&nbsp;Mohammad Reza Kavianpour,&nbsp;Mohammad Saeed Najafi,&nbsp;Razieh Noroozian","doi":"10.1007/s11600-026-02016-x","DOIUrl":"10.1007/s11600-026-02016-x","url":null,"abstract":"<div><p>Nowadays, with the increase in the frequency of extreme rainfall events, the alerts provided by real-time flood forecasting systems are becoming essential to provide accurate and timely information for emergency response. This study uses the Weather Research and Forecasting (WRF) model and the Hydrologic Engineering Center-Hydrologic Modeling System (HEC-HMS) to assess heavy rainfall and runoff forecasting. The models were applied to the upstream basin of Shahid Kazemi Dam, Zarineh-Rood River, located northwest of Iran. The predictability of the WRF model with different microphysics, cumulus (CU), and planetary boundary layer (PBL) parameterizations is evaluated to identify the best set of physics parameters and optimize WRF for forecasting heavy rainfall events. The HEC-HMS model was calibrated by comparing its results with the data observed at gauge stations. The output rainfall data from the top 9 configurations of the WRF model were used as rainfall input in the calibrated HEC-HMS model to investigate the importance of the physical parameterization of the WRF model in runoff forecasting, and the results were examined using statistical indices. Kessler, MYJ, and Grell 3D schemes show the best results for microphysics, CU, and PBL. Consequently, this configuration is recommended for short-term rainfall forecasting tasks in northwest Iran. However, the accurate performance of the WRF model alongside HEC-HMS depends on choosing the best configuration. Still, optimal schemes for precipitation forecasting do not always provide the best estimates for runoff in the basin. The findings of this research could aid in developing a dynamic atmospheric-hydrologic integration system, enhancing flood prediction accuracy across various watersheds and climatic conditions.</p></div>","PeriodicalId":6988,"journal":{"name":"Acta Geophysica","volume":"74 5","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11600-026-02016-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148926998","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":"Coupling WRF with HEC-HMS for streamflow forecasting in typical mountainous catchments of northwestern Iran","authors":"Sajad Akbari Moghaddam Sani,&nbsp;Mohammad Reza Kavianpour,&nbsp;Mohammad Saeed Najafi,&nbsp;Razieh Noroozian","doi":"10.1007/s11600-026-02016-x","DOIUrl":"10.1007/s11600-026-02016-x","url":null,"abstract":"<div><p>Nowadays, with the increase in the frequency of extreme rainfall events, the alerts provided by real-time flood forecasting systems are becoming essential to provide accurate and timely information for emergency response. This study uses the Weather Research and Forecasting (WRF) model and the Hydrologic Engineering Center-Hydrologic Modeling System (HEC-HMS) to assess heavy rainfall and runoff forecasting. The models were applied to the upstream basin of Shahid Kazemi Dam, Zarineh-Rood River, located northwest of Iran. The predictability of the WRF model with different microphysics, cumulus (CU), and planetary boundary layer (PBL) parameterizations is evaluated to identify the best set of physics parameters and optimize WRF for forecasting heavy rainfall events. The HEC-HMS model was calibrated by comparing its results with the data observed at gauge stations. The output rainfall data from the top 9 configurations of the WRF model were used as rainfall input in the calibrated HEC-HMS model to investigate the importance of the physical parameterization of the WRF model in runoff forecasting, and the results were examined using statistical indices. Kessler, MYJ, and Grell 3D schemes show the best results for microphysics, CU, and PBL. Consequently, this configuration is recommended for short-term rainfall forecasting tasks in northwest Iran. However, the accurate performance of the WRF model alongside HEC-HMS depends on choosing the best configuration. Still, optimal schemes for precipitation forecasting do not always provide the best estimates for runoff in the basin. The findings of this research could aid in developing a dynamic atmospheric-hydrologic integration system, enhancing flood prediction accuracy across various watersheds and climatic conditions.</p></div>","PeriodicalId":6988,"journal":{"name":"Acta Geophysica","volume":"74 5","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11600-026-02016-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148927001","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":"Geophysical attribute-driven Hamiltonian eigenanalysis for reservoir attenuation gradient estimation","authors":"Haitao Yan,&nbsp;Dan Li,&nbsp;Nanke Wu,&nbsp;Wei Zhou","doi":"10.1007/s11600-026-02011-2","DOIUrl":"10.1007/s11600-026-02011-2","url":null,"abstract":"<div><p>Seismic attenuation gradient estimation is a critical yet challenging task in hydrocarbon reservoir characterization, as it directly reflects subsurface lithology and fluid saturation. Traditional methods rely on empirical relationships or simplified physical models that do not adequately capture complex wave propagation in heterogeneous media. We present an attribute-driven extension of the quantum-mechanics-inspired absorption method of Xue et al. (2023) for seismic attenuation gradient estimation. Instead of constructing the Hamiltonian potential field from the raw seismic amplitude, our method derives two complementary hydrocarbon-sensitive attributes—the instantaneous envelope and the S-transform-based instantaneous centroid frequency—that are fused and regularized through anisotropic Gaussian smoothing to form an effective potential field. A discrete Hamiltonian is constructed as a finite-difference discretization of the time-independent Schrödinger equation, and its dominant eigenfunctions serve as an orthonormal, data-adaptive basis. Projecting the trace onto these eigenstates and fitting the local log-spectral decay slope via a Morlet continuous wavelet transform yields a per-sample attenuation gradient, which is synthesized across eigenstates by an energy-weighted average. Tests on two synthetic models with known Q fields and on a 2-D post-stack line from the South China Sea, evaluated through RMSE, SSIM, layer-localization error, and well-log Pearson’s correlation, demonstrate improved localization accuracy and noise robustness relative to conventional time–frequency methods and the amplitude-driven baseline of Xue et al. (2023). The method extends quantum-mechanics-inspired signal representation to multi-attribute geophysical fusion.</p></div>","PeriodicalId":6988,"journal":{"name":"Acta Geophysica","volume":"74 5","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148926997","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":"Integrating satellite gravimetry and ground-based SGI diagnostics for groundwater drought assessment in Greece (2002–2023)","authors":"Gözde N. Akşan","doi":"10.1007/s11600-026-01995-1","DOIUrl":"10.1007/s11600-026-01995-1","url":null,"abstract":"<div><p>Groundwater is a critical component of water security in Mediterranean countries, yet it is increasingly threatened by climate variability, recurrent droughts, and anthropogenic pressures. This study presents an integrated groundwater drought assessment framework for Greece by combining GRACE/GRACE-FO-derived groundwater storage anomaly (GWSA) time series with Standardized Groundwater Index (SGI) diagnostics for the period 2002–2023. Monthly GWSA records were obtained for 13 observation points distributed across Greece, and missing observations, including the 2017–2018 GRACE/GRACE-FO mission gap, were reconstructed using a Python-based KNN-GapFiller algorithm. Cross-validation results demonstrated strong reconstruction performance (RMSE = 7.90, NSE = 0.94, PCC = 0.97), confirming the reliability of the reconstructed time series. The resulting GWSA records were analyzed using an automated SGI workflow to identify groundwater drought events, quantify drought severity and duration, and evaluate long-term trends using the Mann–Kendall test and Sen’s slope estimator. Results revealed widespread groundwater depletion across Greece, with 12 of the 13 observation points exhibiting negative groundwater trends. The strongest declines were observed in northeastern Greece, where Sen’s slope values reached approximately −3.9 mm year⁻¹, whereas only one observation point showed a significant positive trend. SGI analyses further identified recurrent groundwater drought episodes, particularly during 2007–2009 and 2012–2013, together with increasing drought persistence in several regions. Overall, the proposed framework integrates machine-learning-based reconstruction of incomplete GRACE/GRACE-FO records with SGI-based groundwater drought diagnostics, providing a reproducible approach for groundwater drought monitoring and supporting sustainable groundwater management and climate adaptation in Mediterranean environments.</p></div>","PeriodicalId":6988,"journal":{"name":"Acta Geophysica","volume":"74 5","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148927103","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":"Integrating satellite gravimetry and ground-based SGI diagnostics for groundwater drought assessment in Greece (2002–2023)","authors":"Gözde N. Akşan","doi":"10.1007/s11600-026-01995-1","DOIUrl":"10.1007/s11600-026-01995-1","url":null,"abstract":"<div><p>Groundwater is a critical component of water security in Mediterranean countries, yet it is increasingly threatened by climate variability, recurrent droughts, and anthropogenic pressures. This study presents an integrated groundwater drought assessment framework for Greece by combining GRACE/GRACE-FO-derived groundwater storage anomaly (GWSA) time series with Standardized Groundwater Index (SGI) diagnostics for the period 2002–2023. Monthly GWSA records were obtained for 13 observation points distributed across Greece, and missing observations, including the 2017–2018 GRACE/GRACE-FO mission gap, were reconstructed using a Python-based KNN-GapFiller algorithm. Cross-validation results demonstrated strong reconstruction performance (RMSE = 7.90, NSE = 0.94, PCC = 0.97), confirming the reliability of the reconstructed time series. The resulting GWSA records were analyzed using an automated SGI workflow to identify groundwater drought events, quantify drought severity and duration, and evaluate long-term trends using the Mann–Kendall test and Sen’s slope estimator. Results revealed widespread groundwater depletion across Greece, with 12 of the 13 observation points exhibiting negative groundwater trends. The strongest declines were observed in northeastern Greece, where Sen’s slope values reached approximately −3.9 mm year⁻¹, whereas only one observation point showed a significant positive trend. SGI analyses further identified recurrent groundwater drought episodes, particularly during 2007–2009 and 2012–2013, together with increasing drought persistence in several regions. Overall, the proposed framework integrates machine-learning-based reconstruction of incomplete GRACE/GRACE-FO records with SGI-based groundwater drought diagnostics, providing a reproducible approach for groundwater drought monitoring and supporting sustainable groundwater management and climate adaptation in Mediterranean environments.</p></div>","PeriodicalId":6988,"journal":{"name":"Acta Geophysica","volume":"74 5","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148927029","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":"Comprehensive geophysical and petrographic approach in seismic hazard assessment: case study of Ransiki Fault Area, South Manokwari Regency, Eastern Indonesia","authors":"Richard Lewerissa,&nbsp;Darma Santi,&nbsp;Laura A. S. Lapono,&nbsp;Restu Tandirerung,&nbsp;Jacson V. Morin,&nbsp;Herlambang Hudha","doi":"10.1007/s11600-026-01987-1","DOIUrl":"10.1007/s11600-026-01987-1","url":null,"abstract":"<div><p>The Ransiki fault zone in South Manokwari Regency, West Papua, Indonesia, poses significant seismic hazards to residents and infrastructure in the region. This study assessed these hazards using a multidisciplinary approach that integrated Probabilistic Seismic Hazard Analysis (PSHA), Horizontal-to-Vertical Spectral Ratio (HVSR) analysis from microtremor recordings, Vertical Electrical Sounding (VES), and petrographic analysis. The PSHA was conducted at 72 points (node spacing 0.1°, ~ 11 km) with 18 HVSR and VES control points using a logic tree with three ground motion prediction equations (GMPE). The results show spectral acceleration (<i>S</i>_a) of 0.049–1.185 g at <i>T</i> = 0.2 s and 0.006–0.129 g at <i>T</i> = 2.0 s for a 10% Probability of Exceedance (PoE) in 50 years (~ 475-year recurrence), with the highest hazard along the Ransiki Fault. HVSR analysis at 18 stations revealed natural frequencies (<span>(f_{0})</span>) of 0.350–9.480 Hz, amplification factors (<span>(A_{0})</span>) of 1.970–5.460, and dominant periods (<span>(T_{0})</span>) of 0.105–2.860 s. HVSR curves from Raipawi Village (<span>(f_{0})</span> = 0.35 Hz; <span>(A_{0})</span> = 5.46) and Wariab Village (<span>(f_{0})</span> = 1.5 Hz; <span>(A_{0})</span> = 4.70) show site response contrasts that reflect subsurface geological heterogeneity. VES surveys at four earthquake-affected locations identified water-saturated sediment layers and potential aquifer zones at depths of 5–60 m, with resistivity values of 2.62–2554.73 Ohm m, indicating high liquefaction risk in the southern coastal plains. Petrographic analysis identified andesite and sublitharenite as the dominant lithologies, each with different seismic loading susceptibility. The integrated dataset produced a detailed seismic hazard zoning map that established a vulnerability gradient from north to south. This study is the first geophysical and petrographic seismic hazard assessment in the Ransiki District, providing a scientific foundation for earthquake-resistant infrastructure design and spatial planning in high-risk Eastern Indonesia.</p></div>","PeriodicalId":6988,"journal":{"name":"Acta Geophysica","volume":"74 5","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148926954","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":"Seismicity patterns and b-value variability in the Santorini–Amorgos system within the South Aegean volcanic arc","authors":"Gulten Polat,&nbsp;Günseli Erdem Altın","doi":"10.1007/s11600-026-02007-y","DOIUrl":"10.1007/s11600-026-02007-y","url":null,"abstract":"&lt;div&gt;&lt;p&gt;The Santorini–Amorgos system is one of the most active volcanic–tectonic settings of the South Aegean Volcanic Arc, where crustal extension, active faulting, volcanism, and recurrent seismicity interact within a complex geodynamic environment. This study investigates the spatial and temporal characteristics of seismicity using the homogeneous National Observatory of Athens–Hellenic Unified Seismological Network (NOA-HUSN) earthquake catalogue for the period from 17 March 2017 to 3 February 2026. An initial catalogue of 38,137 earthquakes was extracted within 33.5°–37.5° N and 18.8°–29.5° E. Following quality control and the application of focal-depth and magnitude criteria, 36,195 crustal earthquakes with depths of 2–40 km and local magnitudes of ML 1.0–6.3 were retained. Magnitude completeness (Mc), Gutenberg-Richter &lt;i&gt;b&lt;/i&gt;-values, and Omori–Utsu &lt;i&gt;p&lt;/i&gt;-values were evaluated using frequency–magnitude statistics, sliding-window analyses, spatial gridding, node-specific completeness estimates, and bootstrap uncertainty analysis. The maximum-curvature method yielded Mc = 2.15, and a conservative reference threshold of Mc₀ = 2.35 was adopted for the fixed-threshold analyses. Spatially smoothed &lt;i&gt;b&lt;/i&gt;-value estimates range from approximately 0.4–1.8 and reveal pronounced regional heterogeneity in earthquake magnitude–frequency characteristics. Relatively low &lt;i&gt;b&lt;/i&gt;-values occur within several earthquake-dense and structurally organized seismic corridors, whereas moderately elevated values form discontinuous patches in several offshore sectors surrounding the central tectonic corridor. No specific anomaly is assigned directly to the immediate Santorini volcanic complex or Kolumbo volcanic centre, where valid grid estimates are absent or spatially incomplete. Bootstrap-derived uncertainties and the spatial distribution of Mc indicate that the principal patterns are generally stable and unlikely to result primarily from sampling variability or magnitude truncation. Temporal analyses show moderate short-term fluctuations in Mc and &lt;i&gt;b&lt;/i&gt;-values but no persistent long-term monotonic trend. Comparisons between fixed and window-specific completeness thresholds demonstrate that time-dependent Mc estimates can amplify apparent temporal variations in &lt;i&gt;b&lt;/i&gt;-values through methodological coupling, whereas the fixed-threshold approach provides a more stable representation of long-term seismicity evolution. The estimated Omori–Utsu &lt;i&gt;p&lt;/i&gt;-values exhibit limited spatial variability, remaining close to unity (approximately 0.94–1.03). Within the adopted spatially smoothed nearest-neighbour methodology, these estimates represent regional post-mainshock temporal decay characteristics rather than parameters of individually identified aftershock sequences. Accordingly, earthquake magnitude-frequency characteristics exhibit substantially greater regional variability than the estimated temporal decay parameter. These results provide new quantitative","PeriodicalId":6988,"journal":{"name":"Acta Geophysica","volume":"74 5","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148926970","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":"Hydroclimatic memory and scaling effects on drought persistence and complexity across river basins in Türkiye","authors":"Mehmet Ali Çelik","doi":"10.1007/s11600-026-01999-x","DOIUrl":"10.1007/s11600-026-01999-x","url":null,"abstract":"<div><p>Drought constitutes one of the most consequential hydroclimatic hazards under accelerating climate change, yet its temporal memory structure and scale-dependent complexity remain poorly characterized across heterogeneous river basin systems. This study presents the first comprehensive, basin-scale assessment of drought persistence and multifractal organization across all 25 major river basins of Türkiye over the period 1975–2022, employing an integrated analytical framework that combines Detrended Fluctuation Analysis (DFA), Multifractal Detrended Fluctuation Analysis (MFDFA), and complementary parametric and nonparametric trend methods applied to Standardized Precipitation Evapotranspiration Index (SPEI) time series computed at four accumulation scales (1-, 3-, 6-, and 12-month) from ERA5-Land reanalysis data. DFA scaling exponents increased monotonically from near-random behavior at SPEI-1 (<i>α</i> ≈ 0.47–0.64) to strong long-range dependence at SPEI-12 (<i>α</i> ≈ 0.82–1.18), confirming a systematic and scale-dependent strengthening of drought memory with increasing accumulation period. MFDFA revealed a progressive widening of the multifractal spectrum width (Δ<i>α</i>) from 0.32 to 0.70 at SPEI-1 to 0.81–0.87 at SPEI-12, demonstrating that drought variability becomes increasingly heterogeneous, intermittent, and structurally complex at longer timescales. The convergence of persistence, multifractality, and directional drying trends at longer accumulation scales demonstrates that drought dynamics in Türkiye are governed by memory-driven, nonlinear hydroclimatic processes rather than purely stochastic variability. These findings establish that short-term drought indices systematically underestimate long-term drought risk and underscore the critical necessity of integrating scale-aware, memory-informed analytical frameworks into operational drought monitoring, and sustainable water resource management strategies under intensifying climate change.</p></div>","PeriodicalId":6988,"journal":{"name":"Acta Geophysica","volume":"74 5","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148926964","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 kinematics and strain rate field along North Africa from seismic moment tensor summation","authors":"Abdelouahab Issaadi,&nbsp;Abdelhakim Ayadi,&nbsp;Farida Ousadou","doi":"10.1007/s11600-026-01992-4","DOIUrl":"10.1007/s11600-026-01992-4","url":null,"abstract":"<div><p>The geodynamics of northern Africa was examined by several studies following various approaches. All these studies concluded to a NW–SE convergence of the African plate towards the Eurasian plate with different local kinematic pattern. Seismic moment tensor summation method was adopted to study the seismic deformation and present-day kinematic along Northern Africa. In the study area, we have an interaction between the Eurasian, the Arabian and the African plates, exhibiting: (1) a collision movement in the Maghreb, Libya and Egypt with a shortening in the NW–SE direction, (2) a rifting along the Red Sea and (3) a transform fault zone in the Gulf of Aqaba. The seismic activity in Northern Africa is characterized by moderate seismic activity with strong earthquakes occurring episodically, most of the strong events are located in the Maghreb area, especially in Algeria and Morocco, the others are in the Gulf of Aqaba along the Dead Sea Fault (DSF). The seismic moment tensor summation method we adopted, leads to calculate the strain rates in several zones using the available seismic catalog of source parameters of earthquakes for Morocco, Algeria, Tunisia, Libya, and Egypt. The catalog was compiled from several local and global databases such as Harvard CMT, ETHZ, IGN, and RCMT and others from published papers, covering the period from 1954 to 2022. The results show a counterclockwise rotation of Africa with respect to Eurasia. The general direction of movements varies from northward (N10°) in the Gulf of Aqaba to westward (N285°) in the Moroccan Rif. The resulting velocity vectors are compared to the results given by other studies using other approaches.</p></div>","PeriodicalId":6988,"journal":{"name":"Acta Geophysica","volume":"74 5","pages":""},"PeriodicalIF":2.1,"publicationDate":"2026-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148927021","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}