The response of soil chemical properties to seismic events has gained significant attention in recent years due to its potential impact on both the environment and infrastructure. Earthquakes can alter the chemical composition of soils, leading to changes in their mechanical properties, which may subsequently affect the stability of embankments, retaining walls, and other civil infrastructure. This review presents a comprehensive analysis of the chemical changes in soils following earthquake events, with a particular focus on the factors influencing these changes and their implications for engineering applications. The paper examines the underlying mechanisms that govern soil behavior during and after seismic events, including liquefaction, soil consolidation, and contamination from hazardous materials. Furthermore, it highlights the importance of post-earthquake soil chemical analysis in assessing potential hazards, such as the release of harmful substances, and offers recommendations for improving soil management strategies in earthquake-prone regions. By reviewing both experimental studies and field observations, this research aims to provide a deeper understanding of the complex relationship between seismic activity and soil chemistry. The novelty of this review lies in its systematic approach to integrating chemical analysis and seismic impacts on soils, offering valuable insights for engineers, environmental scientists, and policymakers involved in disaster risk management and mitigation. Ultimately, this review serves as a foundational resource for enhancing earthquake-resilient infrastructure in geologically active areas.
This bibliometric analysis aims to examine published articles on anomalies observed in the magnetic field due to earthquakes in fourteen seismically active countries between 1975 and 2024. The data used in this analysis are obtained from the online version of the Scopus database and correspond to 290 publications according to the selection criteria. The bibliometric analysis showed that most of the articles were published in English, with the largest number of publications coming from Japan, China, Türkiye, Indonesia, Mexico, the Philippines, Italy, the Russian Federation, and Chile. Out of the 290 articles reviewed, 28 earthquakes showed changes in 6 parameters. The anomaly of the BH component of the magnetic field accounted for 28% of the total. The change in BZ is 20%, D 18%, ∆F 18%, BX 14%, BY 2%.
LiDAR images of northeastern North Carolina in the southeastern USA revealed a ~60-km-long, E-W-oriented geomorphic lineament that crosses the northern side of the Albemarle embayment, herein named the Roanoke River lineament. It is defined by morphological changes along the Roanoke River valley northeast of Palmyra that are aligned with a gentle ~40-km-long, E-W-oriented, south-facing topographic scarp to the east and an angular stream bend to the west. Based on its oblique orientation relative to the regional ENE-WSW-oriented horizontal compressive stress field, SHmax, and the style of geomorphic anomalies that define the lineament, we interpret the Roanoke River lineament to be the surface expression of a buried sinistral strike-slip fault zone, named herein the Roanoke River fault zone. This proposed fault zone may have formed to accommodate the dilatational change in volume produced by dextral motion across the ~10-km-wide Tar River right-step releasing offset in the dextral East Coast strike-slip fault system (ECFS) beneath the Atlantic Coastal Plain. North of the Roanoke River lineament is the ~55-km-long, WNW-ESE-oriented Corduroy Swamp lineament that coincides with the western Norfolk arch. Based on its oblique orientation relative to SHmax and the geomorphic evidence for uplift along the lineament, we postulate that it is the surface expression of a buried transpressional sinistral strike-slip fault, herein named the Corduroy Swamp fault. The existence of these and other faults interpreted herein could have major implications for the tectonic development of the Albemarle embayment and Norfolk arch along the U.S. Atlantic continental margin.
This study investigates the surface deformation caused by the 28 March 2025 Myanmar earthquake (Mw 7.7) using Interferometric Synthetic Aperture Radar (InSAR) techniques with Sentinel-1 data. The earthquake, occurring along the Sagaing Fault, resulted in significant ground displacement, impacting infrastructure and communities. InSAR analysis reveals detailed deformation patterns, quantified through interferograms, multi-look processing, unwrapped phase data, and displacement maps. Results indicate a rupture zone extending approximately 110 km, with maximum subsidence of -0.82 meters and uplift of 0.18 meters, along the line of sight of satellite (LOS). These findings correlate with observed structural damage and provide insights into the fault's slip distribution. This study demonstrates the effectiveness of InSAR in assessing earthquake-induced deformation, offering valuable data for seismic hazard assessment, disaster response, and long-term resilience planning in this vulnerable region. The integration of satellite-based remote sensing with macroseismic data contributes to a comprehensive understanding of seismic events, supporting improved risk mitigation strategies.
Electrical substations control voltage and the flow of electric energy, assuring optimal electricity transmission from generation plants to users. A detailed performance evaluation of the substation's structures is crucial to deciding whether to demolish or repair. This study analyzed a 200 KV substation's steel structure in China to find an efficient assessment strategy. Structural data and dimensions have been carried out through a holistic site inspection. Different laboratory tests have been conducted to evaluate the material's strength. The finite element method (FEM) has been utilized to develop the structural model, and nonlinear static and time-history analysis has been done with STAAD.Pro-2023. To assess the structural safety of the steel structure, necessary factors such as time-frequency, mode shape, deflections, and strength capacity ratios were studied. Structural data was found from structural analysis, and the Structure's present condition was compared with its initial conditions and allowable limits. The study's findings show a 15% reduction in natural frequencies and extended structural periods, indicating material degradation and potential reductions in dynamic resilience. The strength capacity ratio of the steel structure members was lower than the initial condition.
The short term earthquake prediction problem is considered not solved yet. The new trends on this topic are related to the intrusion of the Artificial Intelligence (AI) with believes it can help significantly to the solution. The case study of an experiment in China during 2023 and published in BSSA (https://pubs.geoscienceworld.org/ssa/ bssa/articleabstract/113/6/2461/627949/Earthquake-Forecasting-Using-Big-Data.) deals with the results critically assessed of the achievements in time, distance and magnitude of forthcoming earthquakes in a test area in China. Some other cases are also presented to help the reader to enter the last published development in the mass media of the topic and some speculations on it. The conclusions are that the proclaimed unprecedented accuracy of predicted parameters of forthcoming seismic events is strongly overestimated.
Bridges are one of the most important elements of the transportation system in all countries. The collapse of a bridge or the time required for the repair of a damaged bridge can lead to traffic disruption and relief operation suspension that in turn results in the increased earthquake cascading tertiary effects. Therefore, reducing the vulnerability of bridges has always been the focus of engineers. The use of shape memory alloys (SMA) is one of the new solutions that have been presented and received attention in this field. The purpose of this research is to investigate the effects of using SMAs on the seismic behavior of straight box deck concrete bridges. For this purpose, a typical box deck concrete bridge is considered, and in the area of the plastic hinges of the bridge piers, the longitudinal steel bars are replaced with nickel-titanium SMA bars. The studied bridge is analyzed in two cases with and without the use of SMA under the effect of 3 categories of acceleration time histories, consisting of 120 strong ground motion records. Finally, the fragility curves for the maximum drift ratio and residual drift ratio values are calculated. The results show that the use of nickel-titanium SMA bars increases the maximum drift ratios and reduces the residual drift ratios. In this way, the permanent deformations will be decreased.
This review paper examines the potential for earthquake-induced liquefaction in reclaimed urban areas, with a focus on Dhaka City as a case study. Rapid urbanization and land reclamation in Dhaka have increased concerns about the stability of reclaimed lands during seismic events. This paper synthesizes findings from prior studies, focusing on geotechnical parameters such as SPT-N values, cone tip resistance, local friction, and friction ratio. Key influencing factors, including peak ground acceleration, earthquake magnitude, soil type, and reclamation methods, are analyzed to assess their role in liquefaction susceptibility. Evidence suggests that areas reclaimed with dredged soil, especially at shallow to moderate depths, are more prone to liquefaction under seismic loading. Variability in parameters such as over-consolidation ratio, lateral earth pressure, and internal friction angle highlights the need for localized investigations. This review emphasizes the importance of integrating advanced geotechnical techniques and seismic risk assessments to ensure the resilience of reclaimed urban areas.
The Air-Cooled Condenser (ACC) structure is one of the pivotal industrial buildings in Combined-Cycled Power Plants. This structure functions as a condenser of water steam, which is conveyed to it through the steam turbine generators, and accumulates the produced water and returns it to the plant’s main water circulation system. While the overall behavior of ACCs under earthquake is fairly known, important details such as the seismic response modification coefficient, R, have been a matter of controversy among the involved engineers. To address these ambiguities and in order to conduct a sure design, a more precise investigation of seismic behavior and response of these structures was deemed to be in demand. Answering this want, a numerical program was created in OpenSees numerical modeling platform to generate models for ACCs of different types, dimensions, and mechanical properties. The numerical results obtained from the analysis, especially for concrete ACCs, for whom investigation of their behaviour was thought to be more necessary, accorded well with the expected seismic behaviour foreseen for these buildings.
Bangladesh, a low-lying riverine nation in South Asia, faces significant vulnerability to natural disasters due to its geographic position at the confluence of the Ganges (Padma), Brahmaputra (Jamuna), and Meghna Rivers. Its proximity to the Bay of Bengal further heightens the risk of frequent tropical cyclones, particularly during the monsoon season. The increasing severity of these events is compounded by climate change. This study assesses the current state of cyclone shelters in two disaster-prone districts, Barguna and Bhola, focusing on their architectural and structural adequacy. It identifies key challenges related to their functionality, highlights deficiencies in disaster preparedness, and evaluates design and construction aspects. The findings provide insights into existing limitations and propose strategic improvements to enhance the resilience and effectiveness of these shelters. Additionally, the study outlines areas for future research to strengthen disaster management initiatives.
The marine and coastal environments of the Scotia Sea regions in the Southern Atlantic Ocean and Antarctica are vulnerable to the potentially disastrous effects of seismic activity along the Scotia Arc. This paper presents a magnetogravimetric study of the Scotia Plate for tsunami characterization. The influence of earthquakes on the Geomagnetic Field (GMF) is investigated using data from INTERMAGNET network observatories. A tectonic model is evaluated using gravity data from NOAA and seismic refraction data from Lamont-Doherty Earth Observatory. The study also assesses the impact on water level (WL) measured at Intergovernmental Oceanographic Commission (IOC) tide gauge stations. Cross Wavelet Transform (XWT) is applied, and a frequency analysis of the GMF is conducted to identify specific frequencies during seismic events. A 2D tectonic model is constructed for the North Scotia Ridge using gravimetric and seismic data to characterize structural boundaries that may be activated during seismic events. Water level records collected from 6 tide gauge stations in the region are filtered and analyzed to identify tsunamis at each station. The results reveal anomalous frequencies in the frequency analysis of the horizontal component of the GMF during the November 25, 2013 earthquake, with high data correlation from different observatories in the study area for periods of 0.5 and 1 hour. Gravimetric modeling delineates faults activated during seismic activity and edges of structures potentially activated due to the transcurrent and compressional nature of the margin. WL anomalies up to 1.30 m are obtained following earthquakes with a magnitude greater than 8. The propagation speed in the study area averaged 460 km/h, consistent with the expected speed for those depths, except for Puerto Argentino, which exceeded them in 50%.
“Living in fear of Nigeria biggest Earthquake” is a sub-heading of the Punch daily newspaper of Nigeria, dated, 21st of August, 2016, reported the earthquake/tremor recently witnessed in the ancient town of Saki, accompanied by a series of aftershock events that lasted for about three (3) months (March/May, 2016) southwest Nigeria[1]. Similarly, roughly five (5) years later, another series of earthquakes/tremors occurred again in Saki town, which was reported by an online news vendor named “Ripples Nigeria” dated September 8, 2021, under the sub-heading of “earth tremor rocks Saki in Oyo state”[2]. However, these events were not captured nor recorded by any of the functional seismological stations in Nigeria. The nearest seismological station located at the Obafemi Awolowo University (OAU) Ile-Ife, also failed to capture the events. We therefore seek to examine the instrumentation of the Nigerian National Network of Seismographic Stations. This is necessary to understand the functionalities and the capabilities of the deployed seismometers in each of the seismic stations. Therefore, we evaluated the bandpass limit of the seismic wave frequency for the respective seismic stations in Nigeria through the computation of the amplitude-frequency response curve, phase response curve, and count to cm/sec.
Fault plane solutions for a group of 104; 4.0 ≤ Mw ≤ 7.1 earthquakes between January 1979 and December 2016, extracted from the Global Centroid Moment Tensor Project catalog. Were used to investigate the regional tectonic stress regime of the Gulf of Guinea region. The idea is to validate the theory of membrane tectonics put forward by Freeth (1977)[1] in which the tectonic of the Gulf of Guinea and the sub-Sahara West Africa region were described based on Freeth (1977)[1]. The tectonic of the Gulf of Guinea and the sub-Sahara West Africa region are based on the movement of the African plate, we emphasized the use of rigorous statistical tests to decide on the quality and variability of the earthquake focal mechanisms (FMSs) utilized for the stress tensor inversion analysis. To constrain our analysis, we have applied both the Algorithm of Michael and Gauss technique in our stress tensor inversion analysis of FMS obtained from the region, and the results are found to be coherent and in good agreement with each other. Both Michael (1984)[2] and Zalohar and Vrabec (2007)[3] techniques show that the regional tectonic stress regime of the Gulf of Guinea and the sub-Sahara West Africa is extensional, which is in good agreement with the work of Freeth (1977)[1]. However, our investigation concluded that the orientation of the extensional stress regime is the same as the orientation of the movement of the African plate, which is towards the Euro-Asia plate.
The devastating earthquakes (M7.8 and M7.5) on 6th February 2023 demonstrate the power of the nature and weakness and fragility of the human society. Affecting more than 20 million people in Turkey, the death poll reaches about 60 000 deaths and about three times more injured, 120 000 buildings destroyed and more than 60 billion economical losses in Turkey and Syria. This tremendous seismic event at the same time gave the possibility to study and extract the lessons learned and to prevent heavy consequences when next similar event occurred. Following the context of the specific behavior of the seismic process this event can be attributed to the terminology using the word “doubles” of such a combination of two very strong earthquakes occurred in close space and time window – near Gaziantep and Kahramanmaraş. The two strong earthquakes of 6th February demonstrated all peculiarities of the seismic process and its geophysical, seismological and social consequences. The similar effects have been observed also in 1904 in Bulgaria. On 4th of April, 1904 two very strong earthquakes (M7.2 and M7.8) occurred in a very close time and space domain. These seismic events can also be classified as a “doublet”. So the comparative analysis of such strong earthquakes can help to understand better the seismic process and the following risks for the population, infrastructure and the affected countries as a whole. This paper is targeted to the comparison of the case studies to the seismic doublets in Bulgaria and Turkey and their peculiarities with a focus on the seismic process, destructions, negative social consequences and the specifics if they exist and to extract knowledge which can be useful for the prevention of all possible negatives. The results obtained suggest that similar seismic events might have very different geophysical, seismological and social consequences due to the resilience and environmental peculiarities of the specifically affected sites.
Solving the problem of predicting earthquakes faces difficulties of both theoretical and practical nature. The reason is that the occurrence of earthquakes depends on many factors, which give rise to various anomalies that are used as precursors. However, because of the complexity of the earthquake process and the unavailability of much information about the detailed structure of the Earth's crust, a small number of them can accurately indicate future seismic events. The results of the application of machine learning and deep learning give hope for the possibility of obtaining more accurate information about future strong earthquakes if disparate factors are combined. To determine the most important signs of an earthquake and determine the spatial location of strong earthquakes in a specific seismically active territory of Uzbekistan, namely, in the Fergana depression, the Cora 3, Cora 4, random forest algorithms of machine learning and LSTM, ANN architectures of deep learning were implemented.
In the central portion of the Arabia-Eurasia collision zone, the Tehran domain is positioned at a transitional boundary between seismotectonic zones of the Central Iranian lowland (to the south) and the Alborz highland (to the north). Consequently, numerous destructive seismic events have occurred in this active tectonic domain. This study delves into the tectonic geomorphology of the region within its northern highland domain, specifically focusing on the hanging wall of the E-striking north-dipping North Tehran fault (NTF) zone. Our findings in this northern domain emphasize several prominent topographic scars as significant co-seismic features. These include huge landslides, rockfalls, rock avalanches, and offset geomorphic surfaces and could be present as the main indirect co-seismic morphological features. Within this seismically active region, the extensive dimensions of these geomorphic pieces of evidence reveal the seismic potential of the Tehran Region to experience really strong earthquakes (i.e. M>7.5). These results contrast with the previous Maximum Credible Earthquake (MCE) magnitude estimated for the Tehran Region (i.e. M~7.2) through different approaches in Seismic Hazard Assessments (SHAs). Consequently, the previous SHAs of the Tehran Region might have underestimated the seismic risk, and therefore, it is necessary to conduct an updated and complementary deterministic SHA based on the more detailed seismogenic geological features in this crucial area.
Bangladesh has encountered a serious and recurring threat from earthquakes. The goal of this study is to determine how much earthquake awareness there is among students nationwide. Our initial objective is to provide an overview of the earthquake risks Bangladesh is prone to, including discussions of previous seismic events and any recently identified threats or scientific advancements. Then, analysis was done with the information collected through survey. The analysis reveals a range of outcomes, from encouraging results to unsettling possibilities. Fifty percent of people have clear idea regarding earthquake and fifty percent people are doubtful on the earthquake issue. Furthermore, though eighty six percent people have idea what to do during earthquake but fourteen percent people have no idea what to do during earthquake. The survey and the result show a variety of outcome. The awareness regarding the earthquake preparedness has increased significantly but not up to the mark. More activities should be implemented for the achievement of the awareness level.
Looking for electromagnetic effects of earthquakes, pulse signals are detected preceding the moment of the event or following it. The advance or delay is from 0 s to 200 s. The signals are observed as single or pair pulses in the frequency range 0-5 Hz. Dynamical spectra of the signals are presented and their characteristics are discussed. The signals impact actively on the magnetosphere and ionosphere. As a result of such impact a sharp change in the regime of geomagnetic pulsation excitation may occur. The detected response of the pulsations is considered and analyzed.
The tectonic stress regime of the Caribbean region has been studied by stress tensor inversion analysis for the area bounded by Latitudes 17.32o to 23.79o N and Longitudes 81.47o to -60.56o E. A total of two hundred and twenty (220) fault plane solutions (FPS), made up of the seismic (earthquake) events that have occurred in the region of the study were found on the data catalog of the project website of the global centroid moment tensor, were employed in this study. To characterize the stress regimes of the region of study, the classification of the region based on the global moment tensor project is as follows: Cuba-zone, Haiti-zone, Dominican-republic, Monapassage, Puerto Rico, Virgin-Island and the Leeward Island. The gravity geophysical method revealed the presence of multiple or swarms of fractured lines within the same geographical range of study which might have developed over the years as a result of the interaction and coupling effect of the plate boundaries that have close proximity to the region of study. The seismicity pattern indicates that none of the provinces or countries located within the Caribbean region is devoid of large-magnitude earthquake occurrences capable of wreaking severe havoc on the immediate environment. Obviously, our stress tensor inversion result indicates two types of stress regimes namely compression and the strike-slip with different orientations. Cuba-zone, Haiti-zone, Dominican Republic, Monapassage, and Leeward Island are governed mainly by compression stress regimes. In contrast, the strike-slip stress regimes mainly govern the Puerto Rico and the Virgin Island.
Rainfall-induced landslides stand as the prevailing geohazard in tropical and subtropical regions. The ongoing global climatic changes have introduced a wave of anomalous rainfall events across the world. These abnormal weather patterns have triggered numerous landslide incidents, resulting in significant loss of life and property. To develop early warning systems for such threats to people in mountainous areas of Chittagong, Bangladesh, it requires an in-depth understanding of the geo-environmental properties of soil slopes under heavy rainfall. Historical records reveal that rainfall in total exceeding 150–250 mm has resulted in both localized slope collapses and debris floods. When it rains heavily, rainwater infiltrates initially unsaturated slopes, elevating the degree of saturation while decreasing soil suction. Consequently, the reduced shear strength along the critical slip surface diminishes the factor of safety (FoS), and slope failure occurs. As a result, studies of soil-water characteristics have been conducted, followed by laboratory testing at the impacted sites, and the study found that rainfall and soil type (fine-grained silt) were the most critical factors behind landslides. The mechanism of slope failure is also demonstrated using a simple numerical infiltration model and a slope stability equation. The soil characteristics, the saturated volumetric water content (θs), closely match the field water holding capacity (θf), with a minor difference of 4-8%, and the drainage condition at the bottom of the slope appear to be important factors. Application of these test results to an early warning system for landslides and flash floods is finally demonstrated based on some simplifying assumptions.
