Earthquake Damage Research Articles

Impacts of earthquake damage on commercial life: A RS and GIS based case study of Kahramanmaraş earthquakes

Earthquakes have negative impacts on societies, both socially and economically, and can disrupt daily life in the affected region. The economic impact of earthquakes is typically analyzed by economists through material losses. However, considering the role and importance of geospatial information, this study aims to develop a new method to analyze the negative impact of earthquakes on economic life by detecting the physical damage in commercial land uses. Within this context, the study uses Geographic Information Systems (GIS) and remote sensing capabilities to detect damaged commercial units based on Point of Interest (POI) data in the Antakya and Defne districts of Hatay, one of the 11 provinces heavily destroyed in Kahramanmaraş earthquakes in Türkiye that occurred on February 6, 2023, with magnitudes of 7.7 and 7.6 Mw. The study, utilizing Geographic Information Systems (GIS) and remote sensing technologies, has provided valuable information on the extent of earthquake-related economic losses in the Antakya and Defne districts of Hatay. Analysis of the point of interest (POI) data shows that 55 % of commercial locations, particularly those in metropolitan centers, were negatively impacted. This significant number emphasizes the deep susceptibility of commercial infrastructure to seismic events and emphasizes the vital necessity for specific recovery and resilience approaches. Methodological novelties enable quick identification of critical services needed for urgent disaster response and improve the accuracy of damage estimates, which are crucial for optimizing resource allocation procedures and providing decision-makers with comprehensive spatial data for strategic planning. The study highlights the importance of geospatial technologies in fully understanding the economic impacts of earthquakes and the role of commercial disruption on disaster preparedness, response, and recovery.

A study of the response of reinforced concrete frames with and without masonry infill walls to earthquake motions

In developing countries prone to frequent earthquakes, it is common practice to use masonry infill walls as partitions in reinforced concrete frame buildings. Frames with infill have smaller drift demands and smaller drift capacities relative to similar frames without infill. Whether the relative reduction in drift demand offsets the plausible reduction in drift capacity remains open to discussion. This investigation provides experimental evidence on drift demands and drift capacities for both frames with and frames without infill. To make fair comparisons, only experiments where sets of nominally identical reinforced concrete frames, at least one frame with no infill and at least one frame with infill, are considered. Because many static experiments provide evidence for the reduction in drift capacity caused by infill, the objective of the dynamic experiments described in this study is to quantify the reduction in drift demand attributed to infill. Results of dynamic tests show that frames with infill drifted no more than one-third the amount similar frames without infill drifted in simulated base motions of the same intensity. Results of static tests show that the smallest drift capacities of frames with infill were approximately one-half of the drift capacities of similar frames without infill. These two experimental observations indicate that infill reduces drift demand more than it reduces drift capacity suggesting an overall beneficial effect of the infill. Field data were used to test this idea. Based on surveys of low-rise school buildings, RC frames with more full-height infill walls tend to have less earthquake damage than frames with less infill. A convenient method to quantify the amount of infill walls in buildings is computing wall ratios defined as the ratio of cross-sectional area of masonry infill walls on ground floor to total floor area above ground floor. Projections of the field data suggest that infill wall ratios of at least 0.5% in both directions of a building reduce the likelihood of severe structural damage by 300% compared with smaller ratios. The use of infill presents an inexpensive yet effective retrofit technique, even if only for temporary use, for strengthening buildings vulnerable to earthquake damage.

Mite allergen levels and fungal counts in children's bedding in four widely separated towns in Japan

We evaluated the relationships between children's housing, earthquake or tsunami damage affecting children, prevalence of allergic diseases, and levels of mite allergens and fungi on children's bedding after the Great East Japan Earthquake in four municipalities in Japan. We surveyed 464 children in Ishinomaki, 254 in Kami, 614 in Iwanuma, and 300 in Oiso whose parents or guardians had completed the International Study of Asthma and Allergies in Childhood questionnaire. We measured the levels of Dermatophagoides 1 allergens (Der 1) (Dermatophagoidespteronyssinus and Dermatophagoides farinae) on children's mattresses or futons and fungal counts (Aspergillus and yeast) between 2016 and 2018. Earthquake damage was significantly greater in Ishinomaki than in the other three municipalities. There were no differences in the prevalence of allergic disease among the four municipalities. Der 1 levels were significantly higher in Ishinomaki than in Iwanuma, but there were no differences among Oiso, Iwanuma, and Kami. Der 1 levels in children with asthma in Iwanuma and with allergic rhinitis in Kami were significantly higher than in those without these conditions. Total fungal counts and Aspergillus counts were highest in Kami and lowest in Oiso. Der 1 levels were significantly correlated with fungal counts in Kami and Iwanuma, but not in Ishinomaki or Oiso. Both Der 1 levels and total fungal counts in Ishinomaki were greater than those in other three municipalities. Housing and allergen-avoidance strategies varied among the four municipalities. Mite allergen and fungal levels in these Japanese municipalities might have been affected by the earthquake and tsunami, and these changes might have affected the prevalence of allergic diseases in children.

Earthquake scenario-specific framework for spatial accessibility analysis (SAA) of emergency shelters: a case study in Xichang City, Sichuan Province, China

The spatial accessibility of emergency shelters, indicating the difficulty of evacuation and rescue, is crucial for disaster mitigation and emergency management. To analyze accessibility, an effective approach is to evaluate the service capacity of emergency shelters. Multifaceted factors were employed to enhance the quantitative accuracy of accessibility indicators. However, scenario-specific analysis has not been emphasized. Considering the devastating potential of great earthquake disasters, we cannot ignore the impact of these scenarios on emergency shelter accessibility, especially in areas with high seismic risk. In this study, we developed an earthquake scenario-specific framework for spatial accessibility analysis (SAA), which integrates the service capacity of emergency shelters and the impact of strong ground motion and fault rupturing. We applied this framework to the urban area of Xichang City in Sichuan Province, western China. Xichang City, located in the linked area of the Anninghe fault and Zemuhe fault with many extreme historical earthquake disaster records, is prone to high seismic risk. We firstly collected emergency shelter and road network data in Xichang City. We then applied SAA based on the road network, using the network analysis method. After that, we analyzed the impact of strong ground motion on accessibility and generated the setback zone of fault rupturing. We integrated the effect of strong ground motion on accessibility within the setback zone of active faults. Finally, we generated a comprehensive accessibility map, considering both the predicted strong ground motion and potential fault rupturing. Our results show that the accessibility level changed in several towns of urban Xichang City due to strong ground motion and fault rupturing. The accessibility level decreased in Lizhou, Xingsheng, and Anning Towns. For areas with mapped fault lines, the accessibility level is Very-Low. Our results demonstrate the impact of earthquake damage on the accessibility of emergency shelters and the complexity of evacuation in earthquake scenarios. In general, we added earthquake rupturing and ground motion characteristics into the SAA framework. This framework will help us enhance the reliability of SAA and the feasibility of seismic vulnerability evaluation.

Seismic risk model for regional buildings that considers the influence of temperature and intensity measures

Probability-based seismic risk and random ground motion theories are used to develop high-precision seismic risk functions and models of regional building portfolios. Seismic intensity measures and structural demand parameters are critical in developing seismic fragility models for building clusters. Earthquake damage data indicate that ambient temperature may influence structural fragility, but the effect of temperature on seismic risk is commonly ignored. A method for quantifying seismic intensity is proposed in this study and optimized using 450,000 acceleration records detected by 15 stations during the Luding earthquake in Sichuan, China, on September 5, 2022. Considering the influence of different temperature fields, the proposed seismic intensity quantification method was used to evaluate structural damage during two destructive earthquakes in Xinjiang, China (the Aktao earthquake on September 2, 2003 and the Zhaosu earthquake on December 1, 2003). Three structural empirical seismic risk matrices and cloud maps were developed, and a vulnerability membership curve was generated using fuzzy decision-making, a membership algorithm, and nonlinear regression. A structural seismic risk index function was proposed, and vulnerability cloud diagrams and curves based on actual structural seismic vulnerability datasets were generated. Together, these analyses demonstrated the impact of temperature and intensity measures on the seismic risk to regional buildings. A model was established to evaluate the seismic risk to typical structures and was validated using historical earthquake damage data from China. This method improves the accuracy of earthquake risk and vulnerability assessments for typical building clusters given the influence of temperature. The developed seismic risk prediction model enables the evaluation of vulnerability and resilience of typical structures under low and high temperatures.

The Influence of Base Isolator on The Reinforced Concrete Structures at Sapadia Mataram Hotel Earthquake-Induced

Ring of Fire and at the intersection of three tectonic plates. Efforts are needed to minimize earthquake damage, one of which is the use of a base isolator system. This study aims to determine the effect of using High Damping Rubber Bearing (HDRB) with a diameter of 800 mm on the behavior of reinforced concrete structures in tall buildings under seismic loads. The research location is the 7-story Sapadia Hotel building in the city of Mataram. The research is conducted by analyzing a 3D model of the fixed base structure and the base isolator structure using numerical analysis. The results show an increase in the base displacement of the base isolator structure by 59% in the x-direction and 44% in the y-direction, while the inter-story displacement decreases by 36% in the x-direction and 69% in the y-direction. The use of base isolators can reduce the shear force by 35% in the x-direction and 15% in the y-direction. Based on the pushover analysis, the roof displacement values for the fixed base and base isolator structures are 0.159 m and 0.129 m respectively. These values can be used to determine the structural performance level according to ATC-40. The maximum drift value for the fixed base structure is 0.0055 m. For the base isolator structure, the maximum drift value is 0.0044 m, categorized as Immediate Occupancy (IO). This value can be used to determine the performance level of the structure based on ATC-40. The maximum drift value of the fixed base structure is 0.0055m. While in the base isolator structure, the maximum drift value is 0.0044 m which is included in Immediate Occupancy (IO). Thus, the use of base isolators in high-level buildings is able to reduce post-earthquake damage and the building is still safe to continue using.

A clustering-based analysis method for simulating seismic damage of buildings in large cities

Earthquakes are major threats to cities. Refined simulations of urban earthquake damage are significant for disaster prevention planning, including post-earthquake emergency rescue operations. However, this approach is time-consuming and computationally demanding. This study presents a novel machine learning method for simulating seismic damage of large urban building groups, thus minimizing the computational time and resources associated with the simulation process. First, the proposed method clusters building structures based on their seismic damage index (DI) under specific ground motions. Subsequently, one structure is selected from each cluster for seismic analysis. This approach significantly reduces the number of analyzed structures. The efficiency and accuracy of this method are studied based on a parametric study that involved an improved K-means clustering algorithm and a grid-based clustering algorithm. A batch-clustering algorithm is also developed to further improve the speed of clustering and efficiency of regional seismic simulations. A large Chinese city is considered as research application example. The results indicated the following: (1) the method based on the improved K-means clustering algorithm was superior; (2) the batch-clustering algorithm significantly speeded up clustering analysis and enhanced efficiency of the seismic simulation; (3) the clustering-based simulation method demonstrated high efficiency and accuracy, with a significant decrease of 90.5% in the calculation time compared with direct nonlinear time history analysis. In addition, the average relative error of the DI was only 11.0%. Moreover, over 85.0% of the structures were estimated to be in the correct damage state.

Field Reconnaissance and Earthquake Vulnerability of the RC Buildings in Adıyaman during 2023 Türkiye Earthquakes

The 6th February 2023 Pazarcık and Elbistan earthquakes (Mw = 7.7 and Mw = 7.6) caused great destruction in many cities and were the disaster of the century for Türkiye. The greatest destruction was caused in the provinces of Hatay, Kahramanmaraş, and Adıyaman during these earthquakes, which were independent of each other and occurred on the same day. Information about earthquakes and strong ground motion records is given within the scope of this study. Reinforced concrete (RC) structures which constitute a large part of the urban building stock in the earthquake region were exposed to structural damage at different levels. The structural damage in the RC structures in the city center, Gölbaşı, and Kahta districts of the province of Adıyaman was evaluated within the scope of earthquake and civil engineering after field investigations. Insufficient RC, low-strength concrete reinforcement problems, RC frame failure, heavy overhang, short columns, soft story, and pounding effect are the main causes of the earthquake damage. The presence of these factors that reduce the earthquake resistance of RC structures increased the damage level. In addition, the fact that the earthquakes occurred nine hours apart and the continuation of aftershocks during that period negatively affected the damage levels. It has been observed that structures that receive the necessary engineering services during the construction and project phases ensure the safety of life and property, even if the structure is slightly damaged. In this study, we also tried to reveal whether the target displacements were satisfactorily represented by numerical analysis for a sample RC structure.

Developing significant earthquake damage scenarios following the July 2018 earthquake swarm in the Sea of Galilee area near the Dead Sea Fault

Developing significant earthquake damage scenarios following the July 2018 earthquake swarm in the Sea of Galilee area near the Dead Sea Fault

Experimental Investigations on the Residual Performance of Earthquake-Damaged Low-Rise-Reinforced Concrete Shear Walls

This study investigates the seismic residual performance of reinforced concrete (RC) shear walls with different levels of earthquake damage through reversed cyclic loading tests. The test specimens include slightly damaged walls, moderately damaged walls, and repaired specimens after moderately damaged walls. From the test and analysis results, it is evident that the residual strength and deformation capacity of slightly and moderately damaged RC shear walls do not decrease compared with the undamaged wall. However, the residual stiffness and energy dissipation capacity of damaged walls significantly decrease. The test results are also compared with the reduction factors for residual stiffness, strength, deformation capacity, and energy dissipation capacity in the FEMA 306 and JBDPA post-earthquake assessment guidelines to assess their applicability. Additionally, this study proposes a simplified model to describe residual lateral capacity curves of damaged RC walls at different damage levels for nonlinear pushover analysis, allowing engineers to easily convert the capacity curves of undamaged walls to damaged ones.

Progressive collapse behaviour of earthquake-damaged interior precast concrete joints with headed bars and plastic hinge relocation

This study investigated progressive collapse behaviour of earthquake-damaged interior precast concrete (PC) joints with headed bars. The main objective was to quantify the impact of slight and moderate earthquake damage on their residual collapse resistance. The research began with a numerical investigation to understand the interaction between a 2D frame’s global response to seismic loading and its local response during a threat-independent progressive collapse event. Additionally, a separate set of numerical studies examined interior PC joints under cyclic loading to determine maximum drift ratio demands, yielding 2.5% for slightly and 3.5% for moderately damaged joints. Subsequently, an experimental programme under quasi-static loading conditions was conducted on five interior PC joints under cyclic loading, followed by progressive collapse resistance tests. Test results indicated that damaged joints exhibited flexural and catenary action during progressive collapse, but compressive arch action could not be mobilised due to residual cracks from the initial cyclic loading phase. Comparing damaged joints to fully intact ones from a companion study revealed deterioration in stiffness and deformation capacity during a subsequent progressive collapse, with degree of severity proportional to the extent of damage sustained in the cyclic loading phase. Relative to the intact joints without being subjected to cyclic loading, moderately damaged specimens exhibited a degradation of 63% in stiffness and 38% in deformation capacity, compared to slightly damaged specimens, which showed reductions of 38% in stiffness and 28% in deformation capacity. In contrast, strain hardening of steel bars in both slightly and moderately damaged specimens led to slightly greater collapse resistance than the intact joints. Additionally, failure mode shifted from ductile fracture to premature pull-through failure of headed bars in moderately damaged specimens. In this regard, in post-earthquake progressive collapse assessment, it is recommended to use maximum crack width thresholds of 0.2 to 1.0 mm for slight damage and 1.0 to 2.0 mm for moderate damage.

Enhanced Documentation and Evaluation of Grouting Process, through the Fusion of Non-Destructive Testing and Evaluation Information—The Case Study of the Katholikon of the Monastery of Panagia Varnakova

The restoration of historic buildings and structures involves a wide range of scientific and technical fields. The grouting process is among an array of rehabilitation and preservation interventions and aims to homogenize the structure after the implementation of strengthening measures. The process can provide important information regarding the state of preservation of the examined structure and correlate the progress of the process with the pathology of the monument. To achieve this, the analysis of typical raw grouting data is progressively fused with additional information from the diagnostic studies, non-destructive testing, geospatial information, and from the calculation and analysis of grouting indices. The restoration project of the Katholikon of the Monastery of Panagia Varnakova in Fokida, Greece was selected as the case study, due to its large scale and the severe earthquake damage it has sustained, which has necessitated comprehensive strengthening interventions and extensive grouting. The implementation of an integrated methodological approach validated the enhanced level of co-analysis, revealing information that is not readily deduced from a typical approach. Selected sub-areas of the Katholikon are presented, demonstrating how the observed pathology can be correlated with the results of the grouting process, while incorporating 3D data, and findings from structural and non-destructive analyses.

A Cost-Effective Earthquake Disaster Assessment Model for Power Systems Based on Nighttime Light Information

The power system is one of the most important urban lifeline engineering systems. Identifying the damage to the power system is an important task in earthquake disaster assessments. Considering the importance of timeliness and accessibility, a hyperparameter optimization model is proposed to address the assessment of disaster losses in power systems on earthquakes. The power system vulnerability on earthquakes, PSVE, is assessed by the hyperparameter optimization model based on nighttime light information. Through the utilization of the computational resources provided by Google Earth Engine, the accuracy of the baseline model has been significantly improved to 87.9%; meanwhile, the cost-effectiveness in the evaluation process is maintained. The PSVE-based damage evaluation has the potential to aid in assessing earthquake damage to cities’ energy supply, power infrastructure, and lighting. Furthermore, the PSVE-based damage evaluation can provide valuable guidance for prioritizing and efficiently allocating resources for rapid repair and reconstruction efforts.

Integrating post-event very high resolution SAR imagery and machine learning for building-level earthquake damage assessment

AbstractEarthquakes have devastating effects on densely urbanised regions, requiring rapid and extensive damage assessment to guide resource allocation and recovery efforts. Traditional damage assessment is time-consuming, resource-intensive, and faces challenges in covering vast affected areas, often limiting timely decision-making. Space-borne synthetic aperture radars (SAR) have gained attention for their all-weather and day-night imaging capabilities. These advantages, coupled with wide coverage, short revisits and very high resolution (VHR), have created opportunities for using SAR data in disaster response. However, most SAR studies for post-earthquake damage assessment rely on change detection methods using pre-event SAR images, which are often unavailable in operational scenarios. Limited studies using solely post-event SAR data primarily concentrate on city-block-level damage assessment, thus not fully exploiting the VHR SAR potential. This paper presents a novel method integrating solely post-event VHR SAR imagery and machine learning (ML) for regional-scale post-earthquake damage assessment at the individual building-level. We first used supervised learning on case-specific datasets, and then introduced a combined learning approach, incorporating inventories from multiple case studies to assess generalisation. Finally, the ML model was tested on unseen study areas, to evaluate its flexibility in unfamiliar contexts. The method was implemented using datasets collected during the Earthquake Engineering Field Investigation Team (EEFIT) reconnaissance missions following the 2021 Nippes earthquake and the 2023 Kahramanmaraş earthquake sequence. The results demonstrate the method’s ability to classify standing and collapsed buildings, achieving up to 72% overall accuracy on unseen regions. The proposed method has potential for future disaster assessments, thereby contributing to more effective earthquake management strategies.

DEEP LEARNING-BASED SCENE CLASSIFICATION OF VERY HIGH-RESOLUTION SATELLITE IMAGERY FOR POST-EARTHQUAKE DAMAGE ASSESSMENT: A CASE STUDY OF THE 2023 KAHRAMANMARAŞ EARTHQUAKES

Abstract. Following the devastating earthquakes in Kahramanmaraş province, Türkiye, on February 6, 2023, which resulted in the loss of over 50,000 lives and damage to more than 84,000 buildings, the pressing need for efficient damage assessment and response became apparent. Traditional on-site assessments are time-consuming and perilous. Most existing research leans towards segmentation and object detection methods for earthquake damage assessment using remotely sensed data, which demand substantial training data, computational resources, and time. A more practical approach can be classifying image patches to identify earthquake-affected areas with damaged buildings. This scene classification method categorizes image patches based on their content. Remote sensing scene classification assigns labels to such images using deep learning various algorithms. In this work, we developed a fully automated system utilizing Maxar’s very high-resolution post-earthquake satellite imagery to classify and map the scenes (image patches) involving collapsed and non-collapsed buildings in Antakya and Iskenderun city centers. Our approach involved two key scene classifiers: Classifier #1, employing deep learning models like ResNet-101, effectively detected building presence within the image scene with remarkable accuracy (99.17%). This classifier served as the foundation for identifying the scenes involving buildings for entire city in order to filter the non-urban land use. Then, Classifier #2, classified building scenes into collapsed and non-collapsed categories. The DenseNet-121 model excelled, achieving an accuracy of 93.33% in this task. In the end, Classifier #2 categorized 2,429 non-collapsed and 449 collapsed scenes in Antakya and 2,291 non-collapsed and 290 collapsed scenes in Iskenderun.

Study on seismic risk assessment model of water supply systems in mainland China

Abstract. Using the peak ground acceleration (PGA) under four exceedance probabilities calculated via a probabilistic seismic hazard analysis method for China, the probability density function of PGA was obtained by fitting with the Cornell seismic hazard exceedance probability PGA function model. Combined with the seismic fragility function of the water supply system calculated on the basis of the empirical matrix of actual earthquake damage and the exposure of fixed assets, the expected seismic loss and expected loss rate models of the water supply system were established, and the classification standard with the expected seismic loss rate of the water supply system as the index was proposed. The seismic fragility of the water supply system was classified, and the exposure of the water supply system was analyzed. The total fixed assets in the Statistical Yearbook of Urban Water Supply, henceforth called Water Supply Yearbook, were taken as the exposure to earthquake in the region. The accuracy of the fragility model in this paper was verified through the actual earthquake damage losses in Deyang. Taking the water supply system of 720 cities in mainland China as an example, the distribution maps of expected seismic loss and expected loss rate were calculated and drawn. The expected loss rate model was verified by the key earthquake prevention areas in mainland China. The assessment model based on the expected loss and expected loss rate was taken as the seismic risk assessment model of water supply systems in mainland China.

Preliminary Geospatial and In Situ Reconnaissance of the 8 September 2023 Moroccan Atlas Earthquake Damage

This research investigates the post-earthquake performances of structures in four rural villages in the Moroccan Atlas, emphasizing common construction system characteristics and design flaws that render buildings susceptible to seismic events. Village selection was based on a prior multispectral satellite-image study, proving effective for planning high-impact, post-earthquake field campaigns. The significance of this research resides in on-site data collection, facilitating the physical assessment of earthquake-induced damage and identification of inherent vulnerabilities in construction systems. The constructions in the study area exhibited structural design deficiencies, inadequate construction techniques, and urban modifiers, leading to damage extensively documented in the literature, as well as less-documented unique damage. Predominant seismic-design shortcomings in the study area included subpar material quality, insufficient earthquake-resistant design, and unskilled labor. In situ data were complemented by a global geospatial approach using differential synthetic aperture radar interferometry with Copernicus Sentinel 1 data. Once calibrated the proposed methodology with field data, the analysis of remote sensing processing results, allow assessing the damages in other earthquake-affected areas, including those not visited in the field but also impacted by the seismic event.

Rapid Earthquake Damage Assessment System in the Black Sea Basin: Selection/Adoption of Ground Motion Prediction Equations with Emphasis in the Cross-Border Areas

In the present study, an effort to propose and adopt appropriate Ground Motion Prediction Equations (GMPEs) for the Rapid Earthquake Damage Assessment System (REDAS) in the Black Sea basin is attempted. Emphasis of GMPE harmonization in the cross-border areas (CBA) is given. For this reason, two distinct sub-areas are investigated, taking into consideration their seismotectonic regime. One sub-area refers to active shallow crustal earthquakes (Greece-Turkey, CBA) and the other to intermediate-depth and shallow crustal earthquakes (Romania-Moldova, Western Black Sea CBA). Testing and ranking of pre-selected GMPEs has been performed using strong motion data of the broader CBA regions of both sub-areas. The final proposed GMPEs to feed the REDA System may assure the effective estimation of ShakeMaps and—in combination with the appropriate vulnerability curves—reliable near-real-time damage assessment in the cross-border earthquake affected areas.

Definitions, Classification Schemes for Active Faults, and Their Application

Active faults are generally defined as faults that have moved in the past and will continue to be active in the future. They are expected to cause deformation and potential disasters if they are localized close to human activities. The definition and classification of active faults are important bases for evaluating the risk. This paper summarizes and compares the history, status, and progress of their definition and classification schemes used in representative countries and regions, as well as in some relevant standards, in active fault mapping, in the construction of spatial databases, and in some other aspects. It is concluded that the current geodynamic setting, existing technical means, geological operability, application purpose, and social acceptability of active faulting hazard in a specific area comprehensively determine the selection of the definition and classification. The key parameter in defining active faults is the time limit. It usually involves four time scales, i.e., Neotectonic (post-Neogene), Quaternary, Late Quaternary, and Holocene. The definition using a short time scale, such as Late Quaternary and Holocene, is usually suitable for the plate boundary zone, which has a high strain rate, but active faults in the intraplate deformation region and stable continental region should be defined with a long time scale, such as the Quaternary and Neotectonics. In addition, the magnitude standard can determine the activity intensity of active faults, which most generally includes three classes, namely, M ≥ 5.0 damaging earthquakes, M ≥ 6.0 strong earthquakes, and M ≥ 6.5 earthquakes that may produce surface displacement or deformation. The M ≥ 5.0 earthquake is generally applicable to regional earthquake prevention and risk mitigation in many countries or regions, but the M ≥ 6.5 earthquake magnitude benchmark is generally used as the standard in rules or regulations regarding active fault avoidance. The most common classification schemes in many countries or regions are based on fault activity, which is reflected mainly by the fault slip rate and fault recurrence interval (FRI), as well as by the last activation time. However, when determining the specific quantitative parameters of the different activity levels of faults, it is necessary to comprehensively consider the differences in activity and ages of the faults in the study region, as well as the amount and validity of existing data for the purpose of classifying different active levels of faults effectively.

An empirical analysis of hyperparameter tuning impact on ensemble machine learning algorithm for earthquake damage prediction

An empirical analysis of hyperparameter tuning impact on ensemble machine learning algorithm for earthquake damage prediction