Journal Summary Geofizika is an diamond open-access (CC-BY-NC 4.0 license), peer-reviewed international journal Geofizika issues contributions dealing with topics concerning physics of the atmosphere, the sea and the Earth's interior The journal is published by the Andrija Mohorovičić Geophysical Institute (Department of Geophysics, Faculty of Science, University of Zagreb, Croatia) JCR (WoS) - Journal Impact Factor (2025) = 1.5 ; JIF quartile = Q3 (Geochemistry & Geophysics, Geosciences Multidisciplinary) Editor-in-Chief : Ivica Vilibić (Ruđer Bošković Institute, Division for Marine and Environmental Research, Zagreb, Croatia; Institute for Adriatic Crops and Karst Reclamation, Split, Croatia)
Andrija Mohorovičić Geophysical Institute, Department of Geophysics, Faculty of Science, University of Zagreb
Forecasting the Discharge of the River Sava in Serbia Using Seasonal Auto-Regressive Integrated Moving Average (SARIMA)
This study evaluates Seasonal Auto-Regressive Integrated Moving Average (SARIMA) techniques for predicting river discharge up to 12 months ahead. The Sava River, Serbia, was chosen as the test basin because it plays a crucial role in regional water resource management. However, accurate long-term discharge prediction is challenging due to climatic variability and non-stationarity in hydrological series. Monthly discharge series from 1926 to 2022 at the Sremska Mitrovica station were modeled and forecasted using SARIMA and compared with Zero-Order Forecasting (ZOF) and Random Forests. The selected SARIMA model predicted discharge with a normalised Root Mean Square Error of 21% and a normalised Mean Absolute Error of 16% calculated as a percentage of mean observed discharge. This study evaluates both classical stochastic methods (SARIMA) and machine learning (Random Forest) for the Sava and underscores the potential for improved hydrological predictions in the Western Balkans. Future research should incorporate additional covariates and apply these models to diverse river systems to enhance predictive accuracy.
Copyright (c) 2026 G e o f i z i k a https://creativecommons.org/licenses/by-nc/4.0
Statistical Assessment of Land Surface Temperature Anomalies Associated with Mw ≥ 5 Earthquakes in Türkiye Using MODIS and ERA5
Since many reported anomalies related to earthquakes are heavily influenced by environmental and meteorological variability, identifying trustworthy precursory signals of earthquakes continues to be one of the most difficult problems in geophysics. Despite ongoing debates regarding its statistical robustness and physical interpretation, land surface temperature (LST) remains an interesting dataset for studying remotely sensed phenomena and their potential relationship with earthquakes. In this study, we statistically evaluate the pre- and post-earthquake surface temperature behavior in relation to 93 earthquakes (Mw ≥ 5.0) that occurred in Türkiye between 2001 and 2024. To improve interpretability and reduce meteorological bias, daily surface temperature data from MODIS satellite measurements were combined with ERA5 reanalysis skin temperature data. Standardized z-scores within a 90-day time frame consisting of 60 days before and 30 days after each event were used to identify anomalies. This asymmetric time window was selected to better capture pre-earthquake signals, which are often weak, intermittent, and less persistent than post-earthquake responses. In general, the results indicate that, particularly for earthquakes with Mw ≥ 6.5, post-earthquake thermal anomalies tend to be more consistent and more clearly distinguishable than those observed beforehand. However, the associated effect sizes are small (Cohen’s d < 0.1), suggesting that although the differences are statistically detectable, they remain limited in magnitude. Pre-earthquake anomalies can still be distinguished from background variability, but they typically remain subtle and close to the noise level. Similar temporal behavior observed in both MODIS and ERA5 datasets further suggests that short-term atmospheric variability alone is unlikely to explain the detected patterns. Taken together, these results imply that land surface temperature anomalies, when considered in isolation, are not sufficient for reliable earthquake prediction. Nevertheless, they may provide useful complementary information when integrated with other geophysical observations. By combining a long-term, multi-event statistical approach with independent meteorological data, this study provides a more robust and balanced assessment of earthquake-related thermal behavior in a tectonically active region. This interpretation is further supported by a representative spatiotemporal case study, which highlights the transition from weak and spatially heterogeneous pre-earthquake anomalies to more coherent patterns following the earthquake.
Planetary-scale sea-level variability in the Adriatic Sea under present and future climate conditions
Sea-level variability on planetary time scales (10–100 d) is a prominent feature of the Adriatic Sea and an important preconditioner of coastal flooding. We characterized its properties in the present climate using the nearly century-long Bakar tide-gauge record (1929–2021) and mean sea-level pressure from ERA5 reanalysis, and assessed projected changes using three regional climate model simulations (ALADIN, CCLM, and RACMO). High coherence between sea level and mean sea-level pressure in the 10–100 d band justified using mean sea-level pressure as a proxy for planetary-scale sea level in future climate. Extreme planetary-scale episodes were defined as sea-level anomalies ≥ +19 cm and mean sea-level pressure ≤ -13.5 hPa, separated by at least ten days. In the past period, extreme sea-level episodes peaked in the cold season, occurred typically once or twice per year, lasted three to six days, and showed no significant century-scale trend in intensity, frequency, or duration. Evaluation of regional climate models for the period 1971–2000 showed that all models reproduced the observed seasonal cycle and episode intensity, while the CCLM and especially RACMO models tended to overestimate frequency and duration. Future projections (2039–2068, 2069–2098) under RCP4.5 and RCP8.5 indicated no robust changes in episode intensity, duration, or frequency suggesting that planetary-scale atmospheric forcing over the northern Adriatic is unlikely to change substantially in warmer climates. Consequently, future flood risk will be governed primarily by mean sea-level rise and its superposition with tides and storm surges, rather than by strengthened planetary-scale anomalies.
Adriatic Sea, sea level, mean sea-level pressure, planetary-scale component, regional climate models, RCP4.5, RCP8.5
Copyright (c) 2025 G e o f i z i k a https://creativecommons.org/licenses/by-nc/4.0
Evaluation of iron-copper mineralisation around Avanos-Ozkonak (Nevsehir, Central Anatolia, Turkey) using satellite-based tectonic lineaments and surface temperature
This research focuses on Özkonak and the surrounding area in the Avanos district, investigating the relationship between tectonic lineaments and the formation of goethite and malachite mineralisation. The study aims to clarify how structural geological features influence the formation processes of these secondary minerals. Recent advances in satellite technology have greatly improved the effectiveness of remote sensing in mineral exploration. The study combined field surveys with Landsat-8 OLI/TIRS satellite imagery, processed using Geomatica, ENVI, and ArcGIS, to investigate the relationship between geological-tectonic lineaments and mineralisation patterns. The results indicate a strong correlation between mineralisation and tectonic lineaments, with significant concentrations of goethite and malachite mineralisation found to the west of Özkonak. This is particularly evident in areas characterised by imbricated thrust faults. These formations are likely to be secondary in the oxidation zone, suggesting the presence of primary sulphide deposits. The occurrence of mineralisation coincides with regions of significant tectonic lineaments, as shown by rose diagrams derived from both field and satellite data. The analysis revealed that the ore veins' position was N830W/170SW. The average orientation of the ore veins aligns with the N80-900W and N30-500E trending lineaments. In addition, a satellite-based surface temperature map indicates higher temperatures in the mineralised areas, which corresponds with the lineament maps. The results of this study could greatly enhance the exploration of primary sulphide deposits, which are the source of secondary mineralisation.
Central Anatolia, Ozkonak, iron-copper mineralization, ineament, surface temperature
Seismic activity and gravity field interpretation for subsurface fault detection on Mount Pandan, Indonesia
Indonesia experiences intense volcanic and tectonic activity due to its strategic location between 6° N–11° S latitude and 95° E–141° E longitude, where several major tectonic plates converge. Physiographically, Mount Pandan is located in the modern Sunda Arc region within the Anticlinorium or Kendeng Zone. Previous research recorded a minor earthquake in 2016, indicating ongoing tectonic activity in the Kendeng Zone, connected to sub-magmatic activity observed in several hot springs in Banyukuning, Jari, and Selogajah. Using gravity data, we identify the relationship between tectonic and magmatic activity through 3D inversion modelling of subsurface structures. This analysis correlates with fault fracture density (FFD) for surfaces with faults or fractures. Identifying the focal mechanism is essential for constructing the fault model of the earthquake source. The movement of Earth’s crust along the Kendeng Fault influences underlying magmatic processes. Evidence of this interaction includes low-density zones and sub-magmatic features, such as the presence of hot springs. Earthquakes around the mountain with magnitudes below 4.0 SR suggest a relationship between the movement of strike-slip faults and oblique reverse faults with magma ascent. 3D inversion modelling reveals four layers: At a depth of 0–0.46 km, with an estimated density range of 1.69–2.69 g/cm³, we interpret the layer as caprock, composed of pyroxene and host rock types. The layer at 0.46–1.14 km, with a density range of 1.31–2.23 g/cm³, is interpreted as a reservoir containing sand and clay rock types. Andesite and volcanic breccia rocks make up the layer at 1.14–1.59 km, with a density range of 2.4–2.8 g/cm³. It is thought to be caprock and intrusion (active fault). We interpret the layer at 1.59–2.43 km, with a density range of 1.43–3.45 g/cm³, as a heat source with basalt rock types and magma content. These findings provide new insights into the subsurface structure and fault dynamics of the Kendeng Zone, contributing to a better understanding of tectono-magmatic interactions in seismically active regions.
The Baranja earthquakes of 1922 and 1924
In regions of low seismicity, such as Baranja in northeastern Croatia, seismic hazard assessments rely heavily on the detailed characterization of the few largest known earthquakes. This study focuses on the two strongest historical earthquakes in the area, which occurred on 24 November 1922 and 12 August 1924. We re-evaluated these events using newly collected macroseismic data from Bosnia and Herzegovina, Croatia, Hungary, and Serbia, expanding the number of intensity observations from 106 to 278 for the earthquake of 1922, whereas the previously macroseismically not analysed event of 1924 is decribed by 14 data points. Using a modified Kövesligethy–Jánosi model that accounts for intensity anisotropy in the epicentral area, we inverted the macroseismic fields to relocate the epicentres and estimate focal depths and magnitudes. Both events were relocated near the village of Zmajevac, within the Bansko Brdo tectonic unit, close to its boundary with the Drava depression. The 1922 epicentre moved 13 km north-northeast of the original location in the Croatian Earthquake Catalogue (CEC), while the 1924 epicentre shifted 22 km westward. Revised moment magnitudes are Mw 5.3 and Mw 4.4 for the 1922 and 1924 events, respectively. Estimated focal depths are shallower than previously listed: 11 km and 8 km, compared to the 18 km and 14 km in CEC. These results indicate that significant seismicity in Baranja is confined to the Bansko Brdo unit, with no evidence of strong earthquakes or faults with sufficient seismogenic potential in the Drava Depression or Northern Baranja–Bačka units. This has important implications for regional seismic hazard estimates. Furthermore, we find no instrumental support for the largest catalogued aftershock of the 1922 event and propose its removal. Finally, we interpret the 1924 earthquake as a late aftershock of the 1922 mainshock, suggesting a dependent relationship between the two.
Geotechnical parameters evaluation using Multichannel Analysis Surface Waves (MASW) in the upstream basin of Chaq-Chaq Dam in Sulaimani, NE Iraq
The velocities of the compressional and shear waves (VP and VS) were determined for seven parallel Multichannel Analysis of Surface Waves (MASW) traverses within the upstream basin of Chaq-Chaq Dam in Sulaimani, Kurdistan Region- Iraq. These traverses were executed with a spacing of 2 meters (m) between the geophones. The objective of this study was to investigate subsurface geological features, determine the depth to bedrock, assess bedrock strength, calculate primary and shear wave velocities, and explore potential causes for the collapse of the constructed Chaq-Chaq Dam. Data was collected using Geometrics Seismodule Controller software and processed using ParkSeis Software. The velocity results indicate that the study area comprises three geological layers: a surface soil layer on top, a middle layer of rock fragments, and a limestone layer at the bottom. The calculated Poisson’s ratio based on VP and VS values for these three layers ranges between 0.35 and 0.39 for the first layer, 0.30 and 0.33 for the second layer, and 0.24 and 0.25 for the third layer. These results suggest that the first layer has relatively high values of Poisson’s ratio, indicating an incompetent soil layer. The second layer exhibits moderate values, suggesting a fairly competent layer of rock fragments, while the third layer has low values, indicating a well-competent limestone layer. The findings also highlight deficiencies in the dam’s design, particularly in the southern parts where most of the traverses show the presence of sinkholes. These sinkholes are likely caused by water infiltration during the rainy winter season. When water pressure is applied to the dam, these sinkholes in the southwestern portion could be attributed as the cause of the dam collapsing. Additionally, the dam side was not properly intertied with the rocks forming the right bank of the dam.
MASW, dynamic moduli, shear wave velocity, Chaq-Chaq dam, Iraqi Kurdistan
Statistical analysis of magnetic susceptibility variations in the flotation tailing of the Rudnik Mine, Republic of Serbia
Mine tailings are increasingly recognized as potential valuable mineral resources. This study applies magnetic susceptibility analysis to three boreholes in flotation tailings from dumps at the Pb-Zn Rudnik Mine, Serbia. The samples were obtained over a small spatial distance (10 cm), allowing for the application of various statistical methods with the obtained dataset. The results indicate that the mutual similarity among boreholes cannot be established with statistical significance; however, certain zones between boreholes exhibit some similarities. These variations are attributed to anthropogenic deposition, where local materials were intermixed and arbitrarily deposited during mining and processing, preventing clear statistical correlations. The study identifies key zones of interest in all three boreholes for further geochemical and mineralogical investigations.
Monitoring and Assessing the Patterns of Urban Growth on Forest Landscapes of Vientiane through Geospatial Approach
Rapid urbanization poses a significant threat to forest landscapes, altering ecosystems and biodiversity. This study investigates the impact of urban growth on forest areas in Vientiane, Lao People's Democratic Republic (Lao PDR), from 1990 to 2023. Using Landsat imagery analysis and GIS modeling, we examined land use changes, urban expansion patterns, and forest cover dynamics. Our analysis revealed significant trends in spatial connections between urban development and deforestation. Key findings show a substantial transformation of the landscape: forest areas decreased by 20.62%, while urban areas expanded by 18.25% over the 33-year period. We observed that urban growth primarily occurred along major transportation corridors and in previously undeveloped areas, leading to forest fragmentation and loss. The study employed visual and spatial analysis methods, including random forest modeling and deep learning techniques, to assess the relationship between urban expansion and forest change. Our results indicate that human activities, economic growth, and population migration are primary drivers of these land use changes. This research has important implications for urban planning and forest conservation. It underscores the urgent need for sustainable urban development strategies that balance growth with environmental preservation. Our findings can inform policymakers and urban planners in developing targeted interventions to mitigate the negative impacts of urbanization on forest ecosystems, promoting more sustainable and resilient urban landscapes
urban growth, forest landscape, deforestation, spatial assessment, geospatial approach and Lao PDR
Study on the response characteristics of source parameters for strong mining tremors
Mine tremors are a significant factor contributing to safety accidents in mining areas, and studying the characteristics of the rupture process at the source of mine tremor is crucial for improving the understanding of the disaster mechanism caused by mine tremors.This paper conducts an in-depth analysis and study of 69 strong mine tremor in Shandong mining areas in China using a combination of numerical simulation and theoretical analysis.Firstly, the waveform recording of strong mine tremors is processed using Fast Fourier Transform (FFT). Subsequently, the noise term, instrument response, path effect, and site response of the monitoring station are eliminated from the waveform recording.Finally, based on the Brune source model, a genetic algorithm is utilized to fit and obtain the source parameters, the response characteristics of source parameters for strong mining tremors are analyzed, and the scale of focal rupture as well as the characteristics of regional stress release are revealed.The results showed that the calculated corner frequencies, seismic moments, moment magnitudes, and stress drops of these strong mining tremors were in the ranges of 0.9-3 Hz, 10¹³-10¹⁵ N·m, 2.7-3.7, and 0.009-0.065 MPa, respectively. The results showed that the mine tremors exhibited cross-correlation relationships between the source parameters similar to those of earthquakes.. This demonstrates that various source parameters of mine tremors have the same physical significance as those of earthquakes in representing the scale of focal rupture and magnitude of regional stress.However, the stress drops of strong mining tremors were orders of magnitude lower than those of earthquakes, indicating that the background stresses of the mining tremors were far smaller than those of earthquakes. This signifies that even relatively small changes in regional stress can potentially trigger the occurrence of mining tremors, we need to pay close attention to factors that can cause regional stress changes during the resource extraction process in mining areas. Meanwhile, compared to earthquake of the same magnitude, mine tremors exhibit a larger rupture scale of the focal body, which may also be one of the reasons why the surface ground motion is often more intense than those caused by earthquakes of the same size. This provides theoretical support for the monitoring and assessment of the risk associated with strong mine tremors.
Multi-Method Analysis of Surface Deformations in Western Anatolia with InSAR and GNSS Data
In this study, geodynamic processes in the Western Anatolia Region were analyzed using Interferometric Synthetic Aperture Radar (InSAR) and Global Navigation Satellite Systems (GNSS) data, incorporating wavelet transformation of InSAR time series based on GNSS observations. InSAR data were processed over a six-year period to produce line of sight (LOS) displacement maps. Ascending and descending track data were merged to derive information on both horizontal and vertical displacements. The InSAR-derived displacements were then compared with GNSS station data from the region to assess variations in the east and up components obtained by both techniques. Significant horizontal and vertical displacements were detected. While the Menemen Plain experienced a subsidence of up to 15 centimeters over a six-year period, the island of Samos experienced a rise of 29 centimeters. The performance of InSAR results was evaluated against GNSS data using Root Mean Square Error (RMSE). The RMSE values significantly decreased after applying corrections to the InSAR processing, indicating improved accuracy. For the DEUG station, the RMSE between InSAR and GNSS time series improved to 1.93% in the east component and 5.29% in the vertical component after wavelet-based noise removal. At the IZMI station, the RMSE was reduced to 2.62% (east) and 6.00% (vertical). Finally, at the CES1 station, the RMSE was reduced to 2.71% for the east component and 5.84% for the vertical component, all after correction.
Geological structural mapping using aeromagnetic data to predict zones of rare earth minerals potential
The application of aeromagnetic anomalies to rare earth mineral (lepidolite) exploration in Ijero-Aramoko pegmatite field Southwestern Nigeria, has been carried out with a view to determining the locations and depth to the lineaments hosting the pegmatite bodies. The methodology adopted involved Euler deconvolution technique applied to the 2-D profile and gridded potential field data to obtain estimates of locations and depths of causative bodies. The data was upward continued to a height of 12 km and the regionals was subtracted to yield the residual aeromagnetic map with enhanced shallow magnetic sources (structures) and anomalies of intrests. The 2-D geomagnetic sections developed along two section lines across the study area delineated suspected fault/fracture zones that area characterized by low magnetic succesptibilty. Euler deconvolution methods was applied to the data with SI values 0.5, 1 and 2. Euler solution for structural indices and the power spectral analysis gave depth values which ranged from < 10 – 50 m for shallow sources, 50 – 250 m for intermediate magnetic sources and 250 – 770 m for deeper sources. The Euler solution for structural indices of 0.5 and 1.0 gives the best solutions. The results of this study showed that pegmatite rich rare earth mineralisation occurs as a magnetic source which exhibited low magnetic intensity at relatively shallow depth. The existence of mining sites close to the lineaments further confirms the evidence of mineralisation of some the geologic structures delineated in the study area.
Characteristics of the 2025 Santorini-Amorgos seismic swarm
This study investigates the spatiotemporal evolution and scaling characteristics of the 2025 seismic swarm in the Santorini–Amorgos region, one of the most seismically and volcanically active zones in the Aegean arc. Using a high-resolution earthquake catalog including 1,601 events (ML ≥ 2.9), we analyze variations in key statistical parameters—including b-value, fractal dimension (Dc), scaling exponent (αb), and the q-parameter—within cumulative time windows. Our findings reveal a marked decrease in b-value and simultaneous increase in Dc during the swarm’s activation phase, consistent with an inverse energy cascade and progressive rupture. The spatial extent of the seismic swarm (L) contracts significantly before expanding during the decay phase, and vertical migration of the seismic barycenter suggests a fluid-triggered nucleation process. 3D visualizations confirm fault-aligned clustering and upward migration patterns, supporting a hybrid rupture mechanism governed by both tectonic faulting and fluid diffusion. These results provide critical insights into the complex dynamics of swarms in extensional volcanic environments and highlight the relevance of fractal and scaling analysis for short-term seismic hazard assessment.
Microearthquake identification and seismicity analysis of the M4.7 Feidong earthquake sequence in Anhui
On September 18, 2024, an M4.7 earthquake struck Feidong County in Hefei, Anhui Province. Located at the complex junction of the Tanlu fault zone, this event exhibited a clear foreshock–mainshock–aftershock evolution, attracting widespread attention. To investigate the aftershock activity and seismogenic structure of this earthquake sequence, this study employs deep learning methods applied to continuous waveform data from the Anhui seismic network for automatic detection. Coupled with precise earthquake relocation, a comprehensive and high-precision seismic catalog was constructed. The relocation results indicate that the Earthquake sequence are mainly distributed along a linear trend in the NE–SW direction, extending approximately 12 km, with hypocentral depths concentrated between 8 and 13 km. Notably, both the mainshock and most aftershocks occur at a depth of about 10.5 km. Focal mechanism solutions reveal that the dominant earthquakes in the region exhibit right-lateral strike-slip rupture on steeply dipping faults trending NE, which is highly consistent with the orientation and structural characteristics of the primary Zhuding–Shimenshan fault in the area. In conjunction with observational evidence of fluid intrusion, it is inferred that fluids may have migrated from the southwest into the seismogenic zone through structural pathways such as the Zhuding–Shimenshan fault and accumulated within a depth range of approximately 10 km near the fault. This fluid accumulation likely induced local stress concentration, which may be the primary trigger for the Feidong earthquake sequence.
Meteorological data-driven approach for soil passability modeling in GIS using machine learning
Vehicle mobility across different terrains depends on a multitude of geographical and meteorological variables. Traditional approaches rely on labor-intensive manual field measurements to assess soil conditions for military or humanitarian vehicle passage. In this study, we aimed to explore novel methods for parameterizing the Cone Index, a fundamental metric for assessing passage feasibility, leveraging meteorological data from the global numerical model GFS. Focusing specifically on chernosols, primarily agricultural soils found in flat, open regions conducive to military operations, we utilized machine learning methods to assess how soil conditions affect vehicle mobility. Through rigorous exploratory analysis, we investigated correlations, model performance metrics, and the relative importance of predictors in Cone Index modeling. Our findings highlight the comparative efficacy of different modeling approaches, particularly emphasizing the utility of the Random Forest method. We identified key environmental conditions under which the model reliably predicts the Cone Index. This sets the baseline for spatial modelling in GIS. Despite these insights, our study is constrained by data limitations and the inherent resolution constraints of the GFS model. The obtained solution lays the initial groundwork for implementing the model in a GIS environment to predict the trafficability of chernosols across the broader European region. Future research will aim to expand the dataset, spatial relationships, and employ models with higher resolution for more robust and accurate predictions.
Research on applying deep learning technology to classify earthquakes and blasting events using a Lightweight Convolutional Neural Network
This paper proposes a lightweight convolutional neural network model to identify the types of natural earthquake and blasting events quickly and accurately. Since an event is generally recorded by several stations, it is necessary to preprocess and classify the data based on the event beforehand. This ensures that different station waveforms of the same event do not appear in any two of the training sets, validation sets, and test sets. With the three-component waveforms recorded by stations after preprocessing as the input, the network model and hyperparameters are optimized by analyzing the average and variance in the accuracy and loss values of the verification set in the fivefold cross-validation, and the accuracy and loss curves in the training process. Finally, the classification results of all stations that achieve a certain signal-to-noise ratio for each event are taken as the output of this event type based on the principle that the majority prevails over the minority. This study uses 2,190 natural and blasting events recorded by the Hainan Seismic Network before August 2022, which includes 53,067 waveforms, to train and test the effectiveness of the model. Twenty percent of those events are selected randomly as the test set. The results showed that out of 438 randomly selected events, 427 were correctly identified, resulting in an accuracy rate of 97.48%. Specifically, the accuracy rate for seismic events was 95.59%, with a recall rate of 89.04%, while the accuracy rate for blasting events was 97.84%, with a recall rate of 99.18%. In conclusion, the convolutional neural network model proposed in this paper can rapidly and accurately identify natural and blasting types in Hainan.
deep learning; classification; earthquake; blasting; CNN-convolutional neural network
Copyright (c) 2025 Geofizika Journal https://creativecommons.org/licenses/by-nc/4.0/
Using empirical methods, GIS and bathymetric survey for assessing the siltation of Sidi-Yacoub Dam (northwestern Algeria)
The silting of dams is a critical issue that requires immediate solutions through a participatory approach involving diverse territorial stakeholders. This approach aims to mitigate sediment inputs and preserve the intrinsic qualities of water resources within dams. In this context, the present study evaluates the siltation rate of the Sidi-Yacoub Dam, located in the Oued El Ardjem watershed, and identifies the primary causes contributing to this phenomenon. The methodology employed combines the analysis of thematic maps with the application of the sedimentation prediction model Previsioni Interimento Serbatoi Artificiali (PISA) to calculate various parameters. The annual average of solid inputs reaching the reservoir is estimated at 376.74 m³/km²/year, corresponding to an overall siltation rate of 0.46 Mm³/year. The preservation of this hydraulic infrastructure is critical to optimizing water resource utilization in the region and supporting its economic and social development. This study underscores the importance of integrating empirical methods, Geographic Information Systems, and bathymetric surveys to achieve a comprehensive understanding of siltation dynamics. The findings indicate that the dam experienced a significant loss of approximately 32.22 Hm³ of capacity between 1985 and 2004, representing an 11.6% reduction in its initial storage volume. These results highlight the urgent need for effective sediment management strategies to ensure the long-term sustainability of water resources in Algeria and other regions confronting similar challenges.
In memoriam: Dragutin Skoko, F.C.A. (24 July 1930 – 6 September 2024)
Utilizing Remote Sensing for Monitoring Land Cover Changes and Land Surface Temperature Fluctuations
Land cover change detection supports many kinds of environmental and human development initiatives in both developed and developing countries over the past twenty-three years, Laos has experienced massive changes in land use resulting in corresponding increases in surface temperature. These changes have been little studied or evaluated empirically. To address this gap, this research study focused on tracking land cover change detection (LCCD) and Land surface temperature (LST) change in the study area of Thakhet Laos. Landsat 5, 8, and Modis datasets were used to analyze the relationship between land use and LST from 2000 to 2023. According to the LCCD results, the forest area decreased from 46,912 km² in 2000 to 33,955 km² in 2023, likely due to human activities and urban transition, while bare land increased and agricultural land decreased. In 2000 the LST values in the study area varied widely. The lowest recorded value is 24°C while the highest is 33°C. In 2023, the LST values ranged from 20°C to 41°C, this indicates an increase in temperatures compared to the previous years overall. The observed increase in urban areas, such as population movement, economic development, industrialization, and urban job creation could be a factor driving the LCCD and LST change.
Human thermal load on foggy and cloudless mornings in the cold season
We investigated the human thermal load in Martonvásár (Hungarian lowland, Carpathian region) in anticyclonic weather conditions in the morning, when a) the sky was completely clear and on the other hand, when b) there was fog. A customizable clothing thermal resistance-operative temperature model was used. The body mass index and the basal metabolic flux density values of the person in the simulations were 25 kgm-2 and 40 Wm-2, respectively. During the observations, weather data was provided by the automatic station of the HungaroMet company and it was accessible on the company's website. We had 77 observations in foggy weather, while we had 46 observations under clear sky conditions in the period between 2019–2023. The following main results should be highlighted: 1) clothing thermal resistance (rcl) varied between 0.5-2.5 clo in the case of fog, while in clear-sky cases rcl was between 0.9-3.5 clo. 2) Based on our data analysis, we estimated that the warming effect of the morning fog was around 0.8 clo. 3) We also showed that the effect of inter-personal variability on rcl was significant when the heat deficit was high (rcl ≥ 2.5 clo) and at this time it was comparable with the degree of the warming effect of fog. It should be mentioned that the analysis of typical weather situations from the point of view of human thermal load is a new field of research, since there is little information available on this subject.
A brief analysis of the supercell storm in Croatia on 19 July 2023
Supercell storms, or super-Cb, are powerful and long-lasting convective systems that can form within statically unstable air mass in favourable dynamic conditions. These severe storm types are characterized by one or more rotation updrafts, usually supported by environmental vertical wind shear. Severity of these systems is usually reflected in heavy precipitation, large hail, hurricane wind gusts and sometimes derecho or tornado events. During July 19th, 2023, super-Cb event hit Croatia, including the capital city, Zagreb. It originated in the western Po River valley, Italy, progressed over Slovenia, Croatia, and finally dissipated over Serbia. Its track crossed about 700 km long path and lasted approximately 9 h, leading to human casualties and heavy property damages. The synoptic and mesoscale conditions leading to the formation of the super-Cb is analysed and discussed. Regular official station data, synoptic charts, upper air soundings, radar, and satellite observations are deployed as well as WRF model simulation performed for this case scenario. This study contributes to better understanding of such phenomena and their destructive potential in the broader region of Croatia and adds to somewhat scarce research field of such weather in this part of the world.
Croatian catalogue and database of focal mechanism solutions, characteristic mechanisms, and stress field properties in the Dinarides and the surrounding regions
This report presents the CroFMS catalogue and database of focal mechanism solutions (FMS). It is based on the first-motion polarity data for earthquakes in Croatia and the neighbouring regions, collected over last four decades. The current catalogue version contains FMS for 410 earthquakes that were computed consistently, using the same programs, velocity models, and sets of parameters. Its content is described in terms of distributions of the time and origin of polarity picks, magnitudes, epicentral distances of stations, the quality marks, the phases used, azimuthal gap and distance to the closest station. It was also shown that solutions from the CroFMS catalogue and those independently obtained from the moment tensor inversions are generally consistent. Comparison of observed FMS with the latest European model of active fault sources (EFSM20) revealed several inconsistencies, most notably in the Zagreb and Petrinja epicentral areas, the greater Rijeka region, the Central Adriatic archipelago, and in the zone of surface traces of the thrust fronts of the East-Bosnian–Durmitor and Drina–Ivanjica nappes in Bosnia and Herzegovina. Spatial averaging of FMS over the whole study area produced maps of characteristic focal mechanisms, which may be found useful in the seismic hazard assessment in the areas where active faults are not identified or characterised. A formal stress inversion of the focal mechanism solutions produced a map of maximum horizontal stress orientations across the study area, revealing localized lateral variations that had not been identified in previous studies. Electronic supplement: Three FMS catalogues in the form of Excel-files are available for free download: The CroFMS catalogue ­– file: CroFMS_2024.xlsx The catalogue of characteristic focal mechanisms based on first-motion polarity solutions only – file: Characteristic_FMP_2024.xlsx The catalogue of characteristic focal mechanisms based on the first-motion polarity solutions and the best double-couple solutions by the moment inversion – file: Characteristic_FMP_MTI_2024.xlsx The first row is the header: N – Serial number of FMS; Year; Month; Day; Hour; Minute; Second; Lat. – latitude °N; Lon. – longitude °E: Depth – in km; M­ – magnitude ML; NP1str – strike of nodal plane 1; NP1dip – dip of nodal plane 1; NP1rake – rake of nodal plane 1; NP2str – strike of nodal plane 2; NP2dip – dip of nodal plane 2; NP2rake – rake of nodal plane 2; Pst – strike of the P-axes; Pdip – dip (plunge) of the P-axes; Tst – strike of the T-axes; Tdip – dip (plunge) of the T-axes; Qual – Quality of solution (1–5). None of the two nodal planes is the preferred one. The catalogues are up to date until 30 June 2024.
Spatial variation of the source mechanisms in the Egyptian continental margin
The spatial variability of the focal mechanism solutions in the NW Egypt Cyrenaica and Levant-north Egypt domains of the Egyptian Continental margin is investigated based on the polarity of the P-wave first motions of eleven earthquakes with local magnitudes ML ranging from 4.2 to 6.2. The identified focal mechanism solutions in the Levant-north Egypt domain are evaluated in two sub-provinces with different geological settings. The first sub-province shows strike-slip faulting mechanisms with right-lateral motion along the NE-trending Rosetta-Qattara fault zone, while the NW-trending Temsah fault zone produces left-lateral strike-slip motion. The inland extension of the Rosetta-Qattara fault zone towards the Western Desert reflects the same sense of motion. Strike-slip faulting with thrust components dominates the focal mechanisms in the second sub-province but with a different stress orientation. A single thrust faulting mechanism event which occurred on the periphery of the continental shelf shows the same common orientation of the stress field at the Hellenic Arc. This type of mechanism in this locality can be explained by the mean of compressional stress transfer towards the coast generated by the accelerated southwest retreat of the Hellenic Trench. The complex regional stress along the Cyprian and Hellenic arcs, the current local structure features, and the dominant orientation of the pre-existing fault are the factors that contribute to the changeable stress pattern field in the Levant-north Egypt domain. A single event in the second domain, the NW Egypt Cyrenaica, is a strike-slip with a right-lateral sense of motion on a WNW-oriented plane, consistent with motion along the WNW tectonic fault which separates the continental shelf from the oceanic crust.
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Results of the magnetometer inter-comparisons during the 2nd Cycle of Geomagnetic Information Renewal in the Republic of Croatia
Between 2017 and 2021, the 2nd Geomagnetic Information Renewal Cycle was carried out on the Croatian Geomagnetic Repeat Stations Network (CGRSN). On several occasions, before and after the survey at CGRSN, the magnetometers used in the survey were tested at the Lonjsko Polje Geomagnetic Observatory (LON). This paper presents the methods and results of these tests. The results verified the correctness of the used magnetometers and confirmed that their absolute accuracy is within the targeted measurement accuracy at the secular point. Despite the favourable results, a detail analysis revealed the presence of a small magnetic offset. This offset was introduced during the comparison process and did not affect the CGRSN measurements results in any way. In this paper, we share our experience which could be instructive for other observers performing similar work. Further testing is needed to determine the exact direction and magnitude of this systematic offset.
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Drought monitoring in Croatia using the standardized precipitation-evapotranspiration index
Several periods of drought in the 21st century have severely affected large parts of Europe and caused considerable economic losses, particularly in the agricultural and energy sectors. While rainfall deficits are one of the main causes of droughts, high temperatures in the summer months exacerbate their development, which can have devastating consequences. This was the case in 2022, when long dry spells were accompanied by several heat waves. In this study, climatological drought monitoring using the Standardized Precipitation Evapotranspiration Index (SPEI) is analyzed with the primary goal of finding the best theoretical distribution for adjusting the water balance (defined as the difference between precipitation and potential evapotranspiration) in Croatia before the index is officially introduced into the operational drought monitoring. Although the SPEI is widely used for drought monitoring, the underlying theoretical distribution of the water balance may differ between regions. The study is based on monthly precipitation amounts and monthly mean values of daily minimum and maximum temperatures observed at 31 main meteorological stations for the period 1961–2022. The analysis is carried out for different time scales, ranging from 1 to 24 months. Among the five distributions considered, a generalized logistic distribution with three parameters (GLO) proves to be the most appropriate. There is general agreement between SPEI and SPI time series, both in terms of sign and intensity. However, in periods with a light to moderate lack of precipitation and high air temperatures, a tendency towards higher drought intensity prevails in the SPEI. A comparative analysis of the 2022 drought in Croatia confirmed the ability of the SPEI to detect a drought earlier than the SPI, which also suggests that a larger area of the country was affected by the drought due to consistent air temperature excesses.
Quo vadis scientia? The tales of recent Croatian publications in geodesy and geophysics
Research publications are a key indicator in evaluations of both the careers of scientists and the performance of research institutions and science systems. However, unprecedented changes in publishing have been made in recent decades following the development of solutions that can be helpful in managing publications and the conjoined peer-review process. In that spirit, we performed a comparative study of research articles reported by the Croatian Committee of Geodesy and Geophysics between two 4-year periods, 2019-2022 and 2015-2018, focusing in particular on the changes in journals and publishers between these periods. Apparently, there is a dramatic change in articles between these two periods, directed toward publishers that have much shorter evaluation times, such as MDPI and Frontiers. In almost all subcategories, the percentage of articles in the MDPI increased several times, reaching approximately 65% in hydrology and physical limnology and 30% in geodesy. We argue that these changes are worsening the reliability of science, driven by the national rules that favor the ‘publish or perish’ principle over the quality of research. Furthermore, we propose a way to cope with this problem at the national level, which should include a transition toward reliable publishers and peer-review assessments implemented during research evaluations.
Croatian publications - geodesy and geophysics
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Night sky brightness trends above Zagreb, 2012–2022
The night sky brightness at the RGN site (near the centre of Zagreb, Croatia) was monitored from January 2012 to August 2022. The first data set, covering the period 2012 to 2017, has already been analysed and the conclusions were published in Andreić (2018). The main conclusions are repeated here for comparison and completeness. The results of the analysis of the second dataset, covering the period from January 2018 to July 2022, are reported here. The first data analysis showed that the average night sky brightness did not change significantly from 2012 to 2017, excluding differences due to annual variations in meteorological parameters. The second data set (2018 to 2022) showed a slight decrease in night sky brightness compared to the first data set. The difference is small, about 0.2 mag/arcsec2 (mean values). In the second data set, there is a trend toward darker nights in later years that began three or four years ago (around 2019 or 2020). It is attributed to the modernisation of the public lighting network, where old, often very poor lighting fixtures are slowly being replaced by modern LED lighting fixtures, and to the effects of climatic changes leading to warmer winters with more clear nights.
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