Search Results (31)

The Marmara region of Türkiye, situated along the North Anatolian Fault Zone (NAFZ), constitutes one of the most seismically active and densely monitored zones globally. Given the region’s high vulnerability and the catastrophic impacts of historical events—notably the 1999 İzmit and 2023 Kahramanmara¸s sequences—there is a critical need for advanced seismic hazard risk assessment (SHRA) methods that move beyond static models. This review examines the paradigm shift from traditional geophysics to big data seismology, characterized by the “Five Vs”: volume, velocity, variety, veracity, and value. Critically, we distinguish between two fundamentally different problems: Earthquake Early Warning (EEW), which operates on sub-second timescales after rupture initiation, and probabilistic earthquake forecasting, which operates on timescales of years to decades. The study discusses how cloud-native platforms such as Azure Databricks, combined with data pipelines using Apache Kafka (version 3.5.1) and Apache Spark (version 4.1.2), enable the real-time processing of petabyte-scale seismic sensor streams. Key technological tools, including Physics-Informed Neural Networks (PINNs) and deep learning models such as PhaseNet, are analyzed for their demonstrated ability to enhance EEW systems through sub-second phase picking and automated event detection. Seismic tomography is also undergoing AI-enabled transformation, yielding higher-resolution subsurface imaging. We present statistical validation metrics and uncertainty quantification methods essential for credible hazard assessment. By addressing computational bottlenecks through hybrid computing architectures and edge computing, this framework aims to improve the warning lead time for Istanbul’s critical infrastructure. This work provides a structured roadmap for bridging the gap between traditional seismic data analysis and operational predictive analytics in the Marmara region. Full article

The dynamic characterization of historical buildings located in a complex geological and seismological context is essential to assess seismic vulnerability and to guide conservation strategies. This study presents a non-invasive, ambient vibration-based, investigation of the Norman Castle of Aci Castello (Sicily, Italy), applying Horizontal to Vertical Spectral Ratio (HVSR), Horizontal to Horizontal Spectral Ratio (HHSR), and Random Decrement Method (RDM) to evaluate the structure’s dynamic behavior and potential Soil–Structure Interaction (SSI) effects. The fundamental site frequency, estimated within a broad plateau in the range 2.05–2.70 Hz, does not overlap with the structural frequencies of the castle, which range approximately from 6.30 Hz to 9.00 Hz in the N–S structural direction and from 3.50 Hz to 8.50 Hz in the E–W direction, indicating absence of global SSI resonance. However, the structure exhibits a complex multimodal response, with direction-dependent behavior evident both in spectral peaks and in damping ratios, ranging from 2.10–7.73% along N–S and 0.90–5.84% along E–W. These behaviors can be interpreted as possibly linked to structural complexity and the interaction with the fractured volcanic substrate, characterized by shallow cavities, as well as to the material degradation of the masonry. In particular, the localized presence of subsurface voids may induce a perturbation of the low-frequency ambient vibration wavefield (e.g., microseisms), producing a localized increase in spectral amplitude observed at Level I. The analysis indicates the absence of global SSI resonance due to the lack of overlap between site and structural fundamental frequencies, while significant local SSI effects, mainly related to cavity-induced wavefield perturbation, are observed and may represent a potential vulnerability factor. These findings highlight the relevance of vibration-based diagnostics for heritage vulnerability assessment and conservation strategies. Full article

This study presents a comprehensive analysis of pre- and co-seismic ionospheric disturbances associated with the 2023 Ms6.2 Jishishan earthquake by leveraging the unique observational strengths of BDS, particularly its high-orbit satellites. A multi-parameter space weather index was employed to effectively isolate seismogenic signals from geomagnetic disturbances, confirming that the main shock occurred during geomagnetically quiet conditions. Statistical analysis of 41 historical earthquakes (Mw ≥ 5.5) reveals that 47.2% were associated with detectable Total Electron Content (TEC) anomalies. An inverse correlation between earthquake magnitude and anomaly detectability within a 31-day window suggests prolonged precursor durations for larger events may produce longer-duration precursory signals, which challenge conventional detection methods. The synergistic capabilities of BDS Geostationary Earth Orbit (GEO) and Inclined Geosynchronous Orbit (IGSO) satellites were demonstrated: GEO satellites provide unprecedented temporal stability for continuous TEC monitoring, while IGSO satellites enable high-resolution spatial mapping of Co-seismic Ionospheric Disturbances (CIDs). The detected CIDs propagated at velocities below 1.6 km/s, consistent with acoustic gravity wave (AGW) mechanisms. A case study during a geomagnetically active period further reveals modulated CID propagation characteristics, indicating potential coupling between seismic forcing and space weather. Our findings validate BDS as a powerful and precise tool for ionospheric seismology and provide critical insights into Lithosphere–Atmosphere–Ionosphere Coupling (LAIC) dynamics. Full article

Earthquake predictability remains a central challenge in seismology. Are earthquakes inherently unpredictable phenomena, or can they be forecasted through advances in technology? Contemporary seismological research continues to pursue this scientific milestone, often referred to as the ‘Holy Grail’ of earthquake prediction. In the direction of earthquake prediction based on historical data, the Grammatical Evolution technique of GenClass demonstrated high predictive accuracy for earthquake magnitude. Similarly, our research team follows this line of reasoning, operating under the belief that nature provides a pattern that, with the appropriate tools, can be decoded. What is certain is that, over the past 30 years, scientists and researchers have made significant strides in the field of seismology, largely aided by the development and application of artificial intelligence techniques. Artificial Neural Networks (ANNs) were first applied in the domain of seismology in 1994. The introduction of deep neural networks (DNNs), characterized by architectures incorporating two hidden layers, followed in 2002. Subsequently, recurrent neural networks (RNNs) were implemented within seismological studies as early as 2007. Most recently, grammatical evolution (GE) has been introduced in seismological studies (2025). Despite continuous progress in the field, achieving the so-called “triple prediction”—the precise estimation of the time, location, and magnitude of an earthquake—remains elusive. Nevertheless, machine learning and soft computing approaches have long played a significant role in seismological research. Concerning these approaches, significant advancements have been achieved, both in mapping seismic patterns and in predicting seismic characteristics on a smaller geographical scale. In this way, our research analyzes historical seismic events from 2004 to 2011 within the latitude range of 21°–79° longitude range of 33°–176°. The data is categorized and classified, with the aim of employing grammatical evolution techniques to achieve more accurate and timely predictions of earthquake magnitudes. This paper presents a systematic effort to enhance magnitude prediction accuracy using GE, contributing to the broader goal of reliable earthquake forecasting. Subsequently, this paper presents the superiority of GenClass, a key element of the grammatical evolution techniques, with an average error of 19%, indicating an overall accuracy of 81%. Full article

The Tokara Islands, a volcanic archipelago located south of Japan’s main islands, experienced earthquake swarm activity in 2025. Public concern has emerged regarding the potential triggering of the anticipated Nankai Trough earthquake, which the Japan Meteorological Agency has dismissed; however, the underlying mechanisms of this seismic activity remain inadequately explained. This study employs Exploratory Data Analysis (EDA) to characterise the statistical properties of the swarm and compare them with historical patterns. Earthquake intervals followed exponential distributions, but swarm events exhibited distinctive short intervals that clearly distinguished them from background seismicity. Similarly, whilst earthquake magnitudes conformed to normal distributions, swarm events demonstrated low mean values and reduced variability, characteristics markedly different from regional background activity. The frequency and magnitude distributions of the 2025 swarm demonstrate remarkable similarity to two previous swarms that occurred in 2021. All the episodes coincided with volcanic activity at Suwanose Island, located approximately 10 km from the epicentral region, suggesting a causal relationship between magmatic processes and seismic activity. Statistical analysis reveals that the earthquake swarm exhibits exceptionally low magnitude scale, characteristics consistent with magma-driven seismicity rather than tectonic stress accumulation. The parameter contrasted markedly with pre-seismic conditions observed before the 2011 Tohoku earthquake, where it was substantially elevated. Our findings indicate that the current seismic activity represents localised volcanic-related processes rather than precursory behaviour associated with major tectonic earthquakes. These results demonstrate the utility of statistical seismology in distinguishing between volcanic and tectonic seismic processes for hazard assessment purposes. Full article

Earthquake prediction remains a significant challenge in seismology, and advancements in signal processing techniques have opened new avenues for improving prediction accuracy. This paper explores the application of Time–Frequency Distributions (TFDs) to seismic signals to identify diagnostic precursory patterns of major earthquakes. TFDs provide a comprehensive analysis of the non-stationary nature of seismic data, allowing for the identification of precursory patterns based on energy concentration features. Current earthquake prediction models primarily focus on long-term forecasts, predicting events by identifying a cycle in historical data, or on nowcasting, providing alerts seconds after a quake has begun. However, both approaches offer limited utility for disaster management, compared to short-term earthquake prediction methods. This paper proposes a new possible precursory pattern of major earthquakes, tested through analysis of recent major earthquakes and their respective prior minor earthquakes for five earthquake-prone countries, namely Türkiye, Indonesia, the Philippines, New Zealand, and Japan. Precursors in the time–frequency domain have been consistently identified in all datasets within several hours or a few days before the major earthquakes occurred, which were not present in the observation and analysis of the earthquake catalogs in the time domain. This research contributes towards the ongoing efforts in earthquake prediction, highlighting the potential of quadratic non-linear TFDs as a significant tool for non-stationary seismic signal analysis. To the best of the authors’ knowledge, no similar approach for consistently identifying earthquake diagnostics precursors has been proposed, and, therefore, we propose a novel approach in reliable earthquake prediction using TFD analysis. Full article

North China is one of the high-risk areas for destructive and strong earthquakes in mainland China and has experienced numerous strong historical earthquakes. An earthquake of magnitude M_W 5.5 struck Pingyuan County, Dezhou city, in Shandong Province, China, on 6 August 2023. This earthquake was the strongest in the eastern North China Craton since the 1976 Tangshan earthquake. Since the earthquake did not produce surface ruptures, the seismogenic structure for fault responsible for the Pingyuan M_W 5.5 earthquake is still unclear. To reveal the subsurface geological structure near the earthquake epicenter, this study used high-resolution two-dimensional (2D) seismic reflection profiles and constructed a three-dimensional (3D) geometric model of the Tuqiao Fault by interpreting the faults in the seismic reflection profiles. This study further combined focal mechanism solutions, aftershock clusters, and other seismological data to discuss the seismogenic fault of the Pingyuan M_W 5.5 earthquake. The results show that the Tuqiao Fault is not the seismogenic fault of the M_W 5.5 earthquake. The actual seismogenic structure may be related to the NE-oriented high-angle strike-slip blind fault developed in the basement. We further propose three possible fault models for the strong seismogenic structure in North China to discuss the potential seismotectonics in this region. Full article

A devastating earthquake took place on 8 April 1893, close to the town of Svilajnac, central Serbia. Over the past decade, significant historical data on the effects of this earthquake has been collected from a variety of sources, including books, scientific publications, reports, newspapers, and coeval chronicles. Additionally, this earthquake was recorded 750 km from the epicenter at the seismological station Rocca di Papa in Rome, Italy. Based on critical review and analysis of the historical data, we demonstrate that the epicentral area of this earthquake was 531 km², and the macroseismic effects were recorded at epicentral distances up to 600 km towards the west (Vienna, Austria) towards the north, up to 500 km (Košice–Michalovce, Slovakia), towards the east up to 460 km (Brašov–Borsec, Romania); and towards the south up to about 300 km (Radoviš, North Macedonia). Finally, we show that the key parameters of the 1893 Svilajnac earthquake are as follows: (1) epicentral intensity, I₀ = IX EMS-98, (2) the estimations of the moment magnitude and focal depth based on the observed intensities, M_W = 6.8 and h = 13 km, respectively, and (3) the epicenter coordinates, 44.160° N and 21.354° E. Full article

The seismicity in the Ionian Sea region is very high. In the historical period, many earthquakes have been reported mainly since the 16th century. In this research, we investigated the historical seismicity in the Ionian Sea, emphasizing earthquakes that have been damaging or strongly felt on Zakynthos (Zante) island. A variety of information sources, which have not been utilized so far and covering the time period from AD 1513 to 1900, were collected and examined. The sources utilized included archives, short chronicles, marginal notes, diaries and official scientific bulletins. This research reveals new information for earthquakes that have remained unknown or little-known in the seismological tradition so far. In addition, new information was found for important and already known earthquake episodes, such as the 1886 large and extensively damaging earthquake in the southwestern Peloponnese and the prolonged and destructive earthquake sequence of 1893 on Zakynthos Island, as well as for the little-known damaging earthquake of 1898. Our research adds new information about the earthquake effects in both the built and natural environments and helps also to correct earthquake dates and to identify spurious events. Full article

Earthquakes have and continue to, occur worldwide, though some places are affected more than others by earthquake-induced ground shaking and the same earthquake can cause more damage in one area than in nearby locations due to site-specific geological site conditions, also known as local site effects. Depending on the chronology of the earthquakes, various disciplines of seismology include instrumental and historical seismology, archaeoseismology, palaeoseismology and neotectonics, each focusing on using specific sources of information to evaluate recent or ancient earthquakes. Past earthquakes are investigated to expand the pre-instrumental and instrumental earthquake catalog and better evaluate a region’s seismic hazard. Archaeoseismology offers a way to achieve these goals because it links how ancient civilizations and their environment might have interacted and responded to past earthquake-induced ground motion and soil amplification. Hence, archaeoseismology explores pre-instrumental (past) earthquakes that might have affected sites of human occupation and their nearby settings, which have left their co-seismic marks in ancient manufactured constructions exhumed by archaeological excavations. However, archaeoseismological observations are often made on a limited epicentral area, poorly constrained dated earthquakes and occasionally on unclear evidence of earthquake damage. Archaeological excavations or field investigations often underestimate the critical role that an archaeological site’s ancient geological site conditions might have played in causing co-seismic structural damage to ancient anthropogenic structures. Nevertheless, the archaeological community might document and inaccurately diagnose structural damage by ancient earthquake shaking to structures and even estimate the size of past earthquakes giving little or no consideration to the role of geological site effects in addressing the causative earthquake. This mixture of factors frequently leads to imprecise estimates of the size of ancient earthquakes and unlikely earthquake environmental impacts, leaving unexplained the location and the moment magnitude of the causative earthquake. Hence, it is essential not to rely solely on earthquake intensities based on archaeologically documented co-seismic damage without assessing the nature of the observed structural damage and the contribution of the geological site effects. This paper explains the geological site effects concept to archaeologists unfamiliar with the notion. It clarifies its role in assessing ground shaking, soil amplification and earthquake intensity by past earthquakes and how and why the geological site effects can be estimated when a site is thought to have been struck by an earthquake. Hence, the geological site effects must be considered when archaeological excavations describe and interpret destruction layers. Conversely, engineers and seismologists dealing with seismic hazard risk assessment must pay close attention to archaeological investigations assessing earthquake intensities and locations based on field evidence of damage to structures attributed to past earthquakes, because the geological site effects might have been factored in inaccurately or not at all. Full article

Historical seismology retrieves information about the effects of earthquakes that occurred in the past, mostly regarding the damage, but also on environmental effects. In this paper, we describe the methodology of our research on earthquake-induced hydrological effects, which have been long observed and documented, and are among the most outstanding coseismic phenomena. The method of research follows two distinct paths, depending on whether the investigated event occurred before or after the end of the 18th Century. For the most ancient events, we present examples of historical accounts, local reports, private letters, and diaries, in which the information of interest is often hidden within broader descriptions and mentioned as a minor curiosity. On the contrary, for more recent earthquakes, the research benefits from the growing interest in naturalistic observations that marked the onset of the 19th Century, and is achieved through detailed descriptions, journals, seismic postcards, and through the first systematic collections of instrumental data. Finally, we describe a possible method of classification of the hydrological data and show an analysis of the potential applications and outcomes of this type of research. Full article

Archived seismograms recorded in the 20th century present a valuable source of information for monitoring earthquake activity. However, old data, which are only available as scanned paper-based images should be digitised and converted from raster to vector format prior to reuse for geophysical modelling. Seismograms have special characteristics and specific featuresrecorded by a seismometer and encrypted in the images: signal trace lines, minute time gaps, timing and wave amplitudes. This information should be recognised and interpreted automatically when processing archives of seismograms containing large collections of data. The objective was to automatically digitise historical seismograms obtained from the archives of the Royal Observatory of Belgium (ROB). The images were originallyrecorded by the Galitzine seismometer in 1954 in Uccle seismic station, Belgium. A dataset included 145 TIFF images which required automatic approach of data processing. Software for digitising seismograms are limited and many have disadvantages. We applied the DigitSeis for machine-based vectorisation and reported here a full workflowof data processing. This included pattern recognition, classification, digitising, corrections and converting TIFFs to the digital vector format. The generated contours of signals were presented as time series and converted into digital format (mat files) which indicated information on ground motion signals contained in analog seismograms. We performed the quality control of the digitised traces in Python to evaluate the discriminating functionality of seismic signals by DigitSeis. We shown a robust approach of DigitSeis as a powerful toolset for processing analog seismic signals. The graphical visualisation of signal traces and analysis of the performed vectorisation results shown that the algorithms of data processing performed accurately and can be recommended in similar applications of seismic signal processing in future related works in geophysical research. Full article

In Late Antiquity and the Early Middle Ages, both coastal and sub-mountainous parts of Colchis underwent rapid urbanization. In the 12th century, the processes of decline began: Large settlements were replaced by small farmsteads with light wooden buildings, and the economy transformed from commodity-based to subsistence-based. What caused this decline? Was it the social and political events linked to the decline of the Byzantine Empire and changes to world trade routes, or were there other reasons? This article provides the answer. The synergy of archaeological, folkloristic, historical cartographic, climatological, seismological, and hydrological data depicts a strong link between these processes and climate change, which occurred at the turn of the 12th–13th centuries. The beginning of cooling led to a crisis in agriculture. A decline in both farming and cattle breeding could not fail to affect demography. Seismic activity, noted in the same period, led to the destruction of many buildings, including temples, and fortresses, and changes in hydrological networks, which were directly linked to climate change and caused water logging, led to a loss of the functions of coastal areas and their disappearance. Full article

The paper presents historical perspective of fibre-optic seismographs designed and constructed at the Institute of Applied Physics at Military University of Technology, Poland based on the so-called minimum configuration of fibre-optic gyroscope. The briefly presented history, which originated in the 1998 by the system named GS-13P, laid solid foundations for the construction of a three-axis fibre-optic seismograph. The presented system meets all technical requirements of rotational seismology in terms of measurement parameters (measuring range from 10⁻⁸ rad/s to several rad/s and frequency from 0.01 Hz to 100 Hz) and utility features (mobility, autonomy, power independence, environmental stability). The presented device provides universal application both for research in engineering applications (high buildings, chimneys, wind towers) as well as in seismological research. Full article

The modern construction revolution throughout the past two decades has brought the need for ground vibration mitigation, and this has been one of the major study areas. These studies were mainly focused on the effect of forestation on vibration reduction as the available natural metamaterial. Physical methods such as the finite element method and the boundary conditions of 2D and 3D applications in ground vibration reduction have been developed. Many researchers, scientists, and organizations in this field have emphasized the importance of these methods theoretically and numerically. This paper presents the historical context of resonant metamaterials (MMs), the current progress of periodic 2D and 3D structures, and the possible future outcomes from the seismic metamaterials (SMs), and it relates them with their elastic counterparts to the natural metamaterial (NMs). The idea of bandgaps (FBGs) in the frequency range of interest is reviewed and discussed in some detail. Moreover, the attenuation associated with ground vibrations, noise, seismology, and the like is explained by managing the peculiar mechanisms of ground vibrations. However, a comprehensive computational review focuses on shielding MMs for ground vibration mitigation in urban areas. This phenomenon led to unique features for various techniques to control the bandgap width for various construction applications. Ecological solutions involve the creation of an economic, environmentally based seismic shield for both the Bragg scattering and the local resonance bandgaps. Reportedly, additive studies based on numerical simulation and experiments have improved the functionality of the 2D and 3D periodic structures. It was found that the mechanical properties differ (i.e., stiffness, Poisson’s ratio, and bulk density) and that the geometrical parameters (i.e., lattice, model dimensions, distance from vibration sources, and number of periodic structures) exhibited strong effects on the width and location of the derived FBGs. The geometrical properties of the used unit cell have a strong effect on the attenuation mechanism. Although deep analysis was created in much of the previous research, it was revealed, based on that research, that the attenuation mechanism is still unclear. However, this review article presents a detailed exposition of the recent research progress of the seismic metamaterials, including 2D, 3D, and the main mechanisms of the theoretical backgrounds of energy attenuation. It also summarizes the effects of the factors on the width and location of the bandgaps at a low frequency. In addition, the natural metamaterials and the study of the urban environment are surveyed. The major findings of this review involve the effectiveness of NMs for different functionalities in ground vibration attenuation, which leads to diverse purposes and applications and proposes a roadmap for developing natural materials for clean and quiet environments. Full article