Potential Earthquake Research Articles

Understanding earthquake potential for future hazard mitigation

This study re-examines a broad region of the Sumatran subduction zone and off-coast southern West Java, building on findings of relative quiescence and utilizing the modified probability gain (mG) concept. By comparing pre- and post-quiescence seismicity, we identify potential earthquake sources and assess associated tsunami hazards. We propose a novel combined model integrating normalized seismicity smoothing, geodetic moment rate, and mG to characterize earthquake likelihood better. This model, coupled with a robust seismicity rate model, enables a spatiotemporal earthquake potential hierarchy for refined seismic hazard assessment. Our results confirm prior quiescence findings in specific zones and identify novel potential source regions for significant future earthquakes. We estimate tsunami height, emphasizing the importance of multiple source areas and static stress loading. By examining pre- and post-event expectations, we aim to improve understanding of major earthquakes in the Sumatran Subduction Zone and inform disaster mitigation strategies. This study provides crucial insights for enhanced regional earthquake and tsunami preparedness.

Modeling peak ground acceleration for earthquake hazard safety evaluation

This paper presents a ground motion prediction (GMP) model using an artificial neural network (ANN) for shallow earthquakes, aimed at improving earthquake hazard safety evaluation. The proposed model leverages essential input variables such as moment magnitude, fault type, epicentral distance, and soil type, with the output variable being peak ground acceleration (PGA) at 5% damping. To develop this model, 885 data pairs were obtained from the Pacific Engineering Research Center, providing a robust dataset for training and validation. The ANN architecture comprises 4 nodes in the input layer, two hidden layers each containing 25 nodes, and a single-node output layer, resulting in 750 unknown weight and bias values that the model must optimize. Following the model assessment, a genetic algorithm (GA) was integrated with the ANN model to enhance its predictive capabilities. This integration aimed to forecast 20 potential earthquake scenarios, a crucial step in validating the model’s effectiveness. The results were promising, as the ANN-GA successfully predicted earthquake occurrences in 15 out of 20 scenarios. These findings underscore the model’s potential in accurately forecasting seismic events, thereby contributing to the development of more resilient infrastructure and better-informed urban planning strategies.

Analysis of Long-Term Monitoring of Radon Levels in a Low-Ventilated, Semi-Underground Laboratory—Dose Estimation and Exploration of Potential Earthquake Precursors

This study involves continuous radon monitoring during the academic year 2023/2024. An Airthings Corentium Home radon detector placed in the basement laboratory of a faculty building in Kosovska Mitrovica (N 42.897°, E 20.867°) was used for continuous measurements. The average radon concentration was 303 Bq/m3, and a seasonal pattern during the measuring period was observed. For the first time, the results were grouped by week, excluding non-working days, to present a real case scenario with the aim of assessing the radon exposure of students, teachers, and employed persons. The inhalation dose from radon (1.54 mSv) was very high considering that exposure occurred in both semesters. Another aspect of continuous radon monitoring was to explore the relationship between indoor radon measurements and the occurrences of earthquakes in the Balkan region. Daily variations in radon (peaks and differences) were analyzed at the monitoring site by using both empirical laws and taking into account the earthquake data set provided by the Seismological Survey of Serbia. The analysis revealed that the events chosen to confirm a clear association between earthquake occurrence and enhanced radon activities in the air(as a precursor of seismic activities) did not meet the required criteria but most likely reflected external meteorological conditions.

Seismic Background Noise Level and Station Detectability in the Flores Sea

The Flores back-arc thrust fissure is a significant contributor to earthquake events in the Flores Sea region, as evidenced by seismic investigations. As part of the endeavor to mitigate earthquake risk, seismic data investigations are necessary due to the high potential for earthquakes in the Flores Sea. Background noise in earthquakes is the term used to describe the micro vibrations that are perpetually produced as a result of natural phenomena, such as ocean waves, wind, or human activities. It is crucial to investigate this cacophony in seismology in order to distinguish the primary earthquake signal. Its spectrum analysis can assist in the identification of land changes and the prediction of tectonic activity. This analysis was conducted by employing the Incorporated Research Institutions for Seismology (IRIS) client function as a fetch data tool and the Modular Utility for Statistical Knowledge Gathering Data browser as a data quality monitoring system to verify the health and reliability of seismic data. The three station sites closest to the Flores Sea are the focus of this research data examination. The study's findings indicate that the recorded data at the station is still dominated by cultural noise, as evidenced by the analysis of the probability density function, power spectral density, and noise spectrograms. Additionally, each station exhibits activity with degrees of probability noise that are both high and variable. These results highlight the need for advanced techniques to filter cultural noise and improve the accuracy of seismic signal interpretation in this region. This analysis contributes to understanding tectonic activity in the Flores Sea and underscores the importance of continuous monitoring for earthquake preparedness and risk reduction.

Source Analysis of April 2, 2023, Magnitude 5.6 Flores Sea Earthquake North of Bima, Sumbawa, Indonesia

Abstract The seismotectonic setting and the potential of significant earthquakes from the Flores Sea region in eastern Indonesia are not well understood. On April 2, 2023, a magnitude 5.6 earthquake occurred north of Bima (Sumbawa), specifically under the Flores Sea. This area has a complex tectonic setting with a Flores back-arc thrust and some local active faults. Our study aims to analyze the source mechanism of this earthquake using moment tensor inversion and hypocenter relocation methods. We utilized five (5) three-component regional BMKG seismic stations for the moment tensor inversion and analyzed aftershocks within one month following the main event for hypocenter relocation purposes. Our findings indicate that the earthquake was generated by an unidentified fault segment with a strike-slip mechanism, either an N/NW-S/SE west-dipping fault segment or an E-W north-dipping fault segment. Through hypocenter relocation, we found that aftershocks were oriented directly to the N/NW-S/SW north of the Flores Thrust fault zone. We interpreted that this earthquake was not directly associated with the activity of the Flores Thrust system. This study can help update our understanding of the active fault system around the Flores Sea and as a constraint to support seismic hazard mitigation.

Spatiotemporal Clustering of Large Earthquakes Along the Central‐Eastern Sections of the Altyn Tagh Fault, China

AbstractThe understanding of the spatial‐temporal distribution of past earthquakes is essential to assess the event recurrence behavior and to estimate the size of potential earthquakes along active strike‐slip fault systems. However, the scarcity of paleoseismic data remains a major hurdle in this endeavor. This is the case of the longest strike‐slip fault in Asia, the Altyn Tagh Fault (ATF). We documented six very likely large earthquakes that potentially ruptured the Aksay section of the ATF. Employing a Bayesian approach, we present modeled date ranges of 6339–5220 BC, 5296–4563 BC, 3026–2677 BC, 1324–808 BC, 314–632 AD, and 915–1300 AD. The mean recurrence time is 1,329 ± 588 years with a coefficient of variation (COV) of ∼0.44. In the same fault section, 90 horizontal offsets record an average coseismic slip of 5.1 ± 1.4 m for the last event and suggest four older earthquakes plausibly with a similar slip distribution. Although at the local‐scale the COV indicates quasi‐periodic rupture behavior, the individual interevent times exhibit significant irregularity, a pattern also observed in adjacent fault sections (Xorxoli, Annanba and Tashi sections). We found that such irregularities are a natural consequence of long‐term fault interactions, which allow for synchronized ruptures along the northern and southern strands of the central‐eastern ATF. Our rupture model highlights bursty periods of seismic activity with mean interevent times of 475 ± 108 years separated by long‐lull periods of 1.1–1.6 kyr. Based on this temporal organization and considering the 401‐year elapsed time since the most recent event on the Xorxoli section, there exists a possibility of a forthcoming large earthquake occurring within the next century.

Seismic scenario simulation and ANN-based ground motion model development on the North Tabriz Fault in Northwest Iran

AbstractEarthquakes pose significant seismic hazards in urban regions, often causing extensive damage to the built environment. In regions lacking robust seismic monitoring networks or sufficient data from historical events, ground motion simulations are crucial for assessing potential earthquake impacts. Yet, validating these simulations is challenging, leading to notable predictive uncertainty. This study aims to simulate four scenario earthquakes with moment magnitudes of 6.8, 7.1, 7.4, and 7.7 in Iran, specifically investigating variations in fault plane rupture and earthquake hypocenter. The North Tabriz Fault (NTF), located within the seismic gap in northwest Iran, is selected as the case study due to the lack of well-recorded ground motions from severe earthquakes, despite historical evidence of large-magnitude events. Simulations are conducted using a stochastic finite-fault ground motion simulation methodology with a dynamic corner frequency. Validation of the simulations is performed by comparing estimated peak ground motions and pseudo-spectral ordinates with existing ground motion models (GMMs), supplemented by inter-period correlation analysis. Simulation results reveal high hazard levels, especially in the northeastern area near the fault plane. Intensity maps in terms of the Modified Mercalli Intensity (MMI) scale underscore the urgency for comprehensive preparedness measures. Finally, a region-specific GMM is developed using Artificial Neural Networks (ANN) to predict peak ground motion parameters with an online platform accessible to end-users.

SEISMIC RATE CHANGES ANALYSIS BASED ON THE SPASIAL DISTRIBUTION SEISMOTECTONICS IN THE SOUTHERN SUMATRA REGION

The southern Sumatra region experiences high seismic activity, often resulting in large earthquakes that cause significant losses. Before such earthquakes, a phenomenon known as seismic quiescence a decrease in seismic activity commonly occurs. This phenomenon can be analyzed through changes in seismic rates using the spatial distribution of Z-values. This study investigates the occurrence of seismic quiescence before major earthquakes and examines changes in seismic rates in southern Sumatra. Used secondary earthquake data from the United States Geological Survey (USGS) for 1973–2023 were analyzed, focusing on the region between 2.050°S–5.885°S and 101.030°E–106.611°E. The study centered on three significant earthquakes: the 2000 (7.9 Mw), 2001 (7.4 Mw), and 2007 (8.4 Mw) events. Seismic rate changes were analyzed using the Z-value method, dividing the region into grids to calculate and spatially distribute Z-values. Results showed seismic quiescence before the 2000 (±16 years), 2001 (±13 years), and 2007 (±17 years) earthquakes in Bengkulu. Additionally, similar phenomena were observed in Bengkulu and Lampung before 2023, suggesting the potential for future significant earthquakes in the region. These findings highlight seismic quiescence as a precursor to major seismic events.

Earthquake Prediction and Alert System Using IoT Infrastructure and Cloud-Based Environmental Data Analysis

Earthquakes are one of the most life-threatening natural phenomena, and their prediction is of constant concern among scientists. The study proposes that abrupt weather parameter value fluctuations may influence the occurrence of shallow seismic events by focusing on developing an innovative concept that combines historical meteorological and seismic data collection to predict potential earthquakes. A machine learning (ML) model utilizing the ML.NET framework was designed and implemented. An analysis was undertaken to identify which modeling approach, value prediction, or data classification performs better in forecasting seismic events. The model was trained on a dataset of 8766 records corresponding to the period from 1 January 2001 to 5 October 2024. The achieved accuracy of the model was 95.65% for earthquake prediction based on weather conditions in the Vrancea region, Romania. The authors proposed a unique alerting algorithm and conducted a case study that evaluates multiple predictive models, varying parameters, and methods to identify the most effective model for seismic event prediction in specific meteorological conditions. The findings demonstrate the potential of combining Internet of Things (IoT)-based environmental monitoring with AI to improve earthquake prediction accuracy and preparedness. An IoT-based application was developed using C# with ASP.NET framework to enhance earthquake prediction and public warning capabilities, leveraging Azure cloud infrastructure. The authors also created a hardware prototype for real-time earthquake alerting, integrating the M5Stack platform with ESP32 and MPU-6050 sensors for validation. The testing phase and results describe the proposed methodology and various scenarios.

Analysis of Earthquake Vulnerability of The Demak Coastal Area based on the HVSR (Horizontal To Vertical Spectral Ratio) Method

<p>Most of the Demak Coastal area, especially on the north coast, has a subsurface structure which is quite thick sediment. The impact of an earthquake will cause damage to subsurface structures and buildings above it, so a method is needed that can determine earthquake vulnerability in an area to take mitigation steps. This research aims to analyze vulnerability to earthquakes based on natural frequency (fo), amplification (Ao) and seismic vulnerability index (SVI). The research was carried out by measuring the microseismic signal response at 89 locations using a 3-component seismograph and data logger. The research results showed that the dominant frequency varied from 0.26 – 5.26 Hz, the amplification factor varied from 0.51 – 3.56 and the seismic susceptibility index varied from 0.14-14.77 micro cm<sup>2</sup>/s. The study area was classified into low SVI (SVI < 5), medium SVI (5 < SVI < 10), and high SVI (SVI > 10). The potential earthquake hazard described by SVI with a value range of 10 < SVI (high classification) is found at observation station 60 (Bedono Hamlet) and observation station 70 (Karangwaru Hamlet Cemetery)</p>

Structural Strength of Buildings at the Islamic University of Indonesia Hospital

<p><em>The 2006 earthquake, with a magnitude of 6.3 and an epicenter in Potrobayan Hamlet, Bantul, Yogyakarta, caused significant damage to building structures in the area. This highlights the importance of structural integrity in earthquake-prone regions of Indonesia, particularly in Bantul. This study aims to analyze the structural strength of the Rumah Sakit Universitas Islam Indonesia (RS UII) against potential earthquakes over the next 50 years. This aligns with the building lifespan guidelines set by the Minister of Public Works Regulation No. 45 of 2007, which states that buildings should be evaluated and possibly repaired after 50 years. In this study, the author utilized RESIST software to assess the structural integrity of RS UII in the face of future seismic events. The results revealed weaknesses in the building's structure, indicating that it may not withstand the displacement caused by seismic loads. Therefore, structural reinforcement is necessary to enhance the building's resistance to larger earthquakes. Based on these findings, this study provides recommendations for structural improvements to ensure the hospital's earthquake resilience for the next 50 years, thus preventing significant structural damage.</em></p>

Mitigation and Optimization of Induced Seismicity Using Physics‐Based Forecasting

AbstractFluid injection can induce seismicity by altering stresses on pre‐existing faults. Here, we investigate minimizing induced earthquake potential by optimizing injection operations in a physics‐based forecasting framework. We built a 3D finite element model of the poroelastic crust for the Raton Basin, Central US, and used it to estimate time dependent Coulomb stress changes due to 25 years of wastewater injection in the region. Our finite element model is complemented by a statistical analysis of the seismogenic index (SI), a proxy for critically stressed faults affected by variations in the pore pressure. Forecasts of seismicity rate from our hybrid physics‐based statistical model suggest that induced seismicity in the Raton Basin, from 2001 to 2022, is still driven by wastewater injection despite declining injection rates since 2011. Our model suggests that pore pressure diffusion is the dominant cause of Coulomb stress changes at seismogenic depth, with poroelastic stress changes contributing about 5% to the driving force. Linear programming optimization for the Raton Basin reveals that it is feasible to reduce earthquake potential for a given amount of injected fluid (safety objective) or maximize fluid injection for a prescribed earthquake potential (economic objective). The optimization tends to spread out high‐rate injectors and shift them to regions of lower SI. The framework has practical importance as a tool to manage injection rate per unit field area to reduce induced earthquake potential. Our optimization framework is both flexible and adaptable to mitigate induced earthquake potential in other regions and for other types of subsurface fluid injection.

Mitigation strategies and policies recommendation for the economic impact of the Sunda Strait Megathrust: Seismic risk probability assessment and cost loss estimates

This study investigates seismic risk and potential impacts of future earthquakes in the Sunda Strait region, known for its susceptibility to significant seismic events due to the subduction of the Indo-Australian Plate beneath the Eurasian Plate. The aim is to assess the likelihood of major earthquakes, estimate their impact, and propose strategies to mitigate associated risks. The research uses historical seismic data and probabilistic models to forecast earthquakes with magnitudes ranging from 6.0 to 8.2 Mw. The Gutenberg-Richter model helps project potential earthquake occurrences and their impacts. The findings suggest that the probability of a major earthquake could occur as early as 2026–2027, with a more significant event estimated to likely occur around 2031. Economic estimates for a 7.8–8.2 Mw earthquake suggest potential damage of up to USD 1.255 billion with significant loss of life. The study identifies key vulnerabilities, such as inadequate building foundations and ineffective disaster management infrastructure, which could worsen the impact of future seismic events. In conclusion, the research highlights the urgent need for comprehensive seismic risk mitigation strategies. Recommendations include reinforcing infrastructure to comply with seismic standards, implementing advanced early warning systems, and enhancing public education on earthquake preparedness. Additionally, government policies must address these issues by increasing funding for disaster management, enforcing building regulations, and incorporating traditional knowledge into construction practices. These measures are essential to reducing future earthquake impacts and improving community resilience.

Experimental study on seismically isolated systems using a novel roller-type bearing with energy dissipation capacity

The roller-type isolation bearing is highly effective in limiting the transmission of lateral seismic forces to the superstructure. This paper introduces a novel roller-type bearing with energy dissipation capacity (RB-EDC), which includes flat bearing seats, rollers, limit plates with energy dissipation capability, and limit rings. The RB-EDC is characterized by its excellent energy dissipation capacity, simple manufacturing process, low cost, vertical tensile bearing capacity and stable performance in extremely cold regions due to its specific configuration and materials. The design procedure for the RB-EDC is detailed herein. Subsequently, pseudo-dynamic comparison tests were conducted on both a seismic isolation system specimen and a RC column specimen under frequent and rare earthquake conditions to validate the damping performance of the RB-EDC. The seismic isolation system consists of the RB-EDC and an RC column identical to the RC column specimen. The results indicate that, compared to the RC column specimen, the column in the seismic isolation system specimen significantly reduces crack distribution ranges, rebar strain, concrete strain, and displacement at the column top under seismic actions. The RB-EDC exhibits significant energy dissipation capacity even during frequent earthquakes, demonstrating effective damping performance. However, the residual displacement of the RB-EDC increases with seismic intensity, which may impact the damping performance of the bearing in future potential earthquakes, indicating the need for further redesign to incorporate self-centering capacity.

Crustal stress near the Yakutat microplate collision from probabilistic earthquake focal mechanisms

Earthquake source characteristics provide a valuable constraint on crustal stress and regional plate tectonics. Earthquake source studies in Yukon and northern British Columbia have been limited by sparse seismic network coverage. In this work, we leverage recent seismic network improvements to estimate focal mechanisms for small- and moderate-magnitude ( M > 2.0) earthquakes from P-wave first-motion polarity data. We invert these data within a probabilistic framework to rigorously quantify mechanism uncertainties. Subsequently, probabilistic earthquake focal mechanisms are used as input for inversions for the orientation of principal stress axes, and stress shape ratio, for spatial windows throughout the region. We implement a novel, data-driven approach to propagate focal mechanism uncertainty in stress inversion. Our results improve the spatial coverage of existing earthquake focal mechanisms and enable an orogenic-scale study of crustal stress near the Yakutat–North America collision. Overall, the region is characterized by a transpressive stress regime. Maximum horizontal compressive stress orientations exhibit a pattern orthogonal to the Yakutat collision syntaxis. Stress inversion results also reveal an abrupt change in orientation east-to-west, which we interpret as a change in stress regime across the Fairweather–Connector–Totschunda fault system that is likely related to coupling between the subducting Yakutat slab and North America. This work improves our understanding of potential earthquake hazards in southwestern Yukon and the surrounding region.

Identification of Potential Earthquake Source Zones in Areas of Recent Tectogenesis Based on Geological and Geomorphological Factors and Tools of Fuzzy Logic: The Greater Caucasus

Identification of Potential Earthquake Source Zones in Areas of Recent Tectogenesis Based on Geological and Geomorphological Factors and Tools of Fuzzy Logic: The Greater Caucasus

Large‐Scale Extensional Strain in Southern Tibet From Sentinel‐1 InSAR and GNSS Data

AbstractIn this study, we utilize C‐band Sentinel‐1 radar images from 2015 to 2022, combined with interseismic horizontal GNSS velocities, to construct large‐scale, high‐resolution, 3‐D velocity and strain rate maps over a vast region of southern Tibet. We show the distribution of prevailing dilatational strain accumulation along the seven major rift zones. Using 2‐D elastic dislocations invoking a two‐fault model in a Bayesian framework, we quantified the decadal extension rates across the seven rift zones, and we suggest a total extension rate of 18.4 ± 1.7 mm/yr, consistent with geological and geodetic estimates. The resulting strain rate maps, combined with the earthquake catalog, help us identify areas with high earthquake potential. Our study enhances our understanding of the present‐day tectonics and kinematics in southern Tibet and provides important constraints for seismic hazard assessment in this region.

Earthquake Risk in Bangladesh: Lesson Learned from Turkiye-Morocco Earthquake

Turkey, Morocco, and Bangladesh are all located in active seismic zones of the Earth’s surface. Recent studies have predicted catastrophic earthquakes in Bangladesh in the near future. Since disasters can act as catalysts for learning by exposing the shortcomings and vulnerabilities of communities or governments, it is believed that Bangladesh has much to learn from the 2023 mega-disasters in Turkey and Morocco. Therefore, this study aims to understand the causes of the catastrophic earthquakes in Turkey and Morocco. The main objective is to analyze the strengths and weaknesses of the disaster management stages during the 2023 earthquakes in Turkey and Morocco, and to compare these with the situation in Bangladesh to better understand potential earthquake risks there. Moreover, the study seeks to develop a framework for Disaster Learning. It follows a qualitative research methodology, with most of the necessary data gathered from existing literature and Key Informant Interviews. The findings suggest that infrastructural vulnerabilities and noncompliance with land use regulations were significant causes of the catastrophic damage in Turkey and Morocco, which are also relevant to the earthquake risks in Bangladesh. Key strengths identified in Turkey include the availability of open spaces for emergency services, wide roads, modern equipment, skilled manpower, military-civilian coordination, and a robust humanitarian response—all areas where Bangladesh has significant deficiencies. Lessons from this study reveal that climatic conditions and debris management could pose major challenges for Bangladesh in the event of a significant earthquake.

National risk assessment of Italian school buildings: The MARS project experience

Strategic buildings, such as schools, play a crucial role in civil society. They are essential not only for the well-being of communities but also for their significance during the emergency and recovery phases following an earthquake. Reliable risk assessment is a powerful tool for implementing effective mitigation strategies. While considerable work has been already done in the literature to develop fragility curves and risk studies for residential buildings, there remains a noticeable gap in addressing risk assessment for school portfolios. As part of the 2019–2021 MARS (Seismic Risk MAps) project, funded by the Italian Civil Protection Department and involving the ReLUIS consortium along with the EUCENTRE foundation, a specific task was dedicated to evaluating seismic risk for the Italian school buildings. In this context, eight research units combined their expertise to develop a consensus-based vulnerability model, known as the “School-MARS model”. This model integrates fragility curves based on various approaches (i.e. empirical, mechanical-analytical, mechanical-numerical and hybrid) and is tailored to archetypes representative of the Italian school buildings. The main goal of the paper is outlining the methodology used to define the “School-MARS vulnerability model”. Moreover, the paper demonstrates the application of the latter for performing intensity-based and time-based risk analyses. Specifically, the results are presented in terms of damage distribution and usability ratings expected for the entire stock of Italian school building. Notably, these results indicate that approximately 26 % of Reinforced Concrete (RC) buildings and 31 % of Unreinforced Masonry (URM) structures may become unusable due to potential earthquakes expected in the next 50 years.

Analisis Deformasi di Lampung dan Selat Sunda berdasarkan Data GNSS tahun 2018 hingga 2021

The Lampung Province and Sunda Strait have a seismic gap zone with the potential for major earthquakes in the future. This study analyzes the deformation occurring in this region using continuous Global Navigation Satellite System (GNSS) station data from Indonesia Continuously Operating Reference Station (InaCORS) and Sumatran GPS Array (SuGAr) from 2018 to 2021.5. The GNSS data was processed using the Bernese 5.2 scientific software, applying least squares for velocity changes and statistical tests to analyze significance. The data processing was carried out in two schemes: the first scheme covering 2018-2020, and the second covering 2019-2021. The results of the deformation analysis from 2018 to 2021, using two continuous GNSS data processing schemes, showed velocity changes relative to the Sundaland Plate ranging from ~2 mm/year to ~20 mm/year. In the eastern region of the Sumatra fault, the velocity changes were smaller, around ~5 mm/year, due to the minimal influence of tectonic activity. However, in the Sunda Strait region, the deformation was influenced by volcanic activity. The deformation occurring in Lampung Province and the Sunda Strait, based on GNSS velocity changes, significantly contributes to tectonic and volcanic activities.