Previous Earthquakes Research Articles

Analysis And Improvement of Poor Bearing Capacity Soils in Düzce Province by Jet grouting Method

Turkey is situated in an earthquake-prone zone, and due to its geographic location, Düzce is among the most hazardous regions in the country and the world. The seismic risk in Düzce province is significantly influenced by the North Anatolian Fault (NAF), which is characterized by an active tectonic structure. This area has experienced earthquakes of varying magnitudes both before and after the instrumental recording period. Especially, two significant earthquakes occurred in 1999: on August 17, an earthquake with a moment magnitude of Mw = 7.4 struck the Adapazarı-İzmit region. Shortly after, on November 12, 1999, another earthquake with a moment magnitude of Mw=7.1 hit Düzce area at approximately 18:57, lasting for about 30 seconds. During the August 17 earthquake, the eastern section of the Düzce fault, measuring 43 km, was activated. The November 12 earthquake is considered to have been triggered by the previously unbroken eastern section of the Düzce fault as a result of the initial faulting. In the city center, the soil composition mainly consists of fine gravel and sandy gravel in certain areas. Previous earthquakes have resulted in structural damages primarily due to bearing capacity issues, and liquefaction phenomena have also been observed in some locations. In this study, the soil beneath a planned three-story building in Düzce, an area identified having a liquefaction risk, was improved using the jet grout method.

Spatial and Temporal Analysis of Earthquake Events in Kahramanmaraş on 6 February 2023

Earthquakes are one of the most destructive natural disasters that occur as a result of the energy resulting from the movements of the earth's crust spreading and shaking the earth's surface. Since it is not possible to predict when and where earthquakes will occur, it has become possible to make various inferences and take necessary precautions by analyzing previous earthquakes. Spatial and temporal analysis of natural disasters such as earthquakes with geographic information systems provides useful information to local and global decision-makers in measures to be taken and mitigation studies. The objective of this study is to demonstrate that the general orientation of stress accumulation on fault lines can be monitored by weighted average centre points with the use of Geographic Information Systems (GIS). Spatio-temporal analyses of two earthquakes with a magnitude of 7.7 Mw and 7.6 Mw in Kahramanmaraş and aftershocks were performed. Ten-week spatial distributions of the aftershocks were examined with the weighted average center method and it was determined that the earthquake intensity and average centers shifted towards the north. When the spatial distribution of the earthquake centers is examined with the help of standard deviation ellipses weekly, it has been determined that they show orientation along the Eastern Anatolian Fault System.

Role of Intraplate Strike-Slip Earthquakes in Accommodating Convergence Across the Eastern Himalayan Plate Boundary System

Abstract North-East India, at the eastern extremity of the Himalaya, is one of the most rapidly deforming intraplate regions. The tectonics of this region is shaped by oblique convergence between two nearly perpendicular plate boundaries of the Eastern Himalaya and the Indo-Burman convergence zone. This region of distributed deformation is associated with intraplate strike-slip and oblique-slip earthquakes. We model the source mechanisms of six recent moderate-to-strong intraplate earthquakes (5.0≤ Mw ≤6.7) using teleseismic P- and SH-waveform inversion and use source directivity and rupture back-projection, for the largest event, to isolate the fault plane. We combine these mechanisms with previous earthquake source studies, GPS-geodetic-velocity vectors, and GPS-derived strain-rate field, to build a kinematic model. Majority of the earthquakes have strike-slip to oblique-slip (thrust) motion and originate in the middle-to-lower crust. These reveal that the entire NE-Indian crust is seismogenic. The oblique-thrust earthquakes occur due to high in-plane compressive stresses in the flexed Indian Plate. The region north of the Dawki Fault, in the vicinity of the Kopili and Dhubri-Chungthang Fault Zones, deforms through dextral strike-slip faulting and anticlockwise rotation of blocks along NW-SE trending transverse structures. The transitional crust of the Bengal Basin has several NE-SW trending paleo-rifts which are reactivated as sinistral strike-slip faults and the intervening blocks undergo clockwise rotation. The oblique convergence between the Indian and Eurasian Plates is partitioned into dextral and sinistral strike-slip motions across NE-India. The GPS velocity vectors and the strain-rate field indicate that the region north of the Dawki Fault has strong coupling between the surface deformation and the earthquake faulting. However, in the region south of the Dawki Fault, the coupling is weaker. The strike-slip earthquakes beneath Indo-Burma probably occur due to a complex interplay between the trench-normal slab-pull forces and lateral-shear forces set up by the strike-parallel components of the interplate-coupling resistance and the mantle-drag forces.

Component‐level seismic fragility database of suspended piping systems in buildings

AbstractNonstructural components (NSCs) contribute about 80%–90% of the construction investment in a modern public building. The post‐earthquake safety and normal operation of NSCs are necessary to achieve performance‐based design and resilient buildings. The piping system is one of the most essential nonstructural systems to preserve the post‐earthquake functionality of public buildings. To accurately evaluate the seismic performance and vulnerability of piping systems in buildings, a component‐level seismic fragility database is urgently to be developed. System composition, failure modes of piping systems, and induced consequences during previous earthquakes are introduced first in this article. Then a concise description of component‐level fragility methodology suggested by the Applied Technology Council is presented. Seismic fragility database of piping components including pipes, piping joints, and seismic braces through quasi‐static tests are developed based on the fragility analysis method. Experimental results from available literature are summarized and presented in the form of seismic fragility curves. Specific hysteretic curves of these components are also presented, which are used for the calibration of numerical models. In addition, the future research directions on the seismic fragility of piping components are summarized and prospected. The developed component‐level seismic fragility database can be used to help understand the seismic performance and post‐earthquake damage states of the piping system. Seismic performance assessment and seismic fragility analysis of modern piping systems can be conducted using the developed database and numerical simulation method.

Influence of retrofitting in the seismic behaviour of precast reinforced concrete industrial buildings

Previous destructive earthquakes caused large economic losses as well as human losses. Seismic risk studies are of paramount importance to predict the impact of future earthquakes and support seismic risk mitigation policies. The present study presents a seismic risk assessment based on the cost and direct loss assessment of precast industrial buildings with different retrofitting levels in terms of horizontal strength. In this evaluation, a comparative analysis between the configurations of retrofitted buildings and the original building is performed. The effects of retrofitting solution strategies are first investigated in a single building. Then a study is carried out to assess which retrofit solutions level are most appropriate depending on the exposure and seismic risk. The results showed the use of bracing in the PRC building can improve seismic behaviour, with significant increases in horizontal strength. The cost of intervention is reduced, with a slight increase of less than 1% to almost 2% of the cost of the structure. From the derivation of seismic fragility functions for different retrofitting solutions level, the seismic risk analysis with dozens of existing PRC industrial buildings in Portugal points to a large reduction in economic losses as from retrofitted buildings, like an improvement of the seismic capacity of the buildings attributed to the retrofit systems considered. In general, among the different types of retrofit studied, there is an increase in the reduction of total economic losses, namely 49% when retrofitted with a 50% increase in horizontal strength, 58% when retrofitted with a 75% increase in horizontal strength and 64% for retrofitted with 100%.

Patients with crush syndrome and kidney disease: lessons learned from the earthquake in Kahramanmaraş, Türkiye

This study investigated in-hospital outcomes and related factors in patients diagnosed with postearthquake crush syndrome after the earthquakes in Kahramanmaraş, Türkiye. One thousand twenty-four adult patients diagnosed with crush syndrome were analyzed. Data on demographic characteristics, clinical presentation, laboratory values, treatments, and outcomes were collected. A total of 9.8% of patients died during their hospital stay. Nonsurvivors were generally older, more likely to have preexisting chronic kidney disease, and faced more severe injuries and complications, including hypotension-shock, arrhythmias, elevated markers of renal dysfunction, and higher rates of acute kidney injury (AKI) and compartment syndrome. In addition, intensive care unit needs were higher. Multivariate analysis confirmed that age, injury severity, shock, high potassium, uric acid, and lactate levels on admission, development of AKI, compartment syndrome, and intensive care unit admission were significant predictors of mortality. Better disaster preparedness and improved health care infrastructure could be potential explanations for improved in-hospital mortality in the current era, as compared to previous earthquakes.

Seismic mitigation of porcelain cylindrical electrical equipment using synergistic concept with base isolation and tuned mass damper

Porcelain cylindrical electrical equipment (PCEEs), such as potential and current transformers, are critical components of electrical substations and essential to power supply networks. Nevertheless, previous strong earthquakes have rendered high vulnerability and poor performance of PCEE during seismic occurrences. To improve seismic performance of PCEE and alleviate adverse seismic impacts, an innovative synergistic mitigation method based on base isolation (BI) and tuned mass damper (TMD) was proposed and subsequently employed to PCEE. Combining BI with TMD allows for a greater utilization of each technology’s capabilities while also circumventing some of the limits of each. While TMD effectiveness is sensitive to input ground motion frequencies, BI could act as a filter to tune input frequency and help TMD fulfill better damping effectiveness. TMD could in return help BI achieve better stability under long-period dominant or pulse-like ground motions. The BI-TMD effectiveness and robustness were investigated using finite element modeling and nonlinear time history analysis. A comprehensive parametric study that considers variable PCEE frequencies, BI periods, TMD mass ratios, and TMD control frequencies was conducted. Results show that the proposed BI-TMD method can significantly enhance the effectiveness and robustness beyond BI single control in mitigating seismic responses of PCEE.

Structural and non-structural fragility curves for low-rise mainshock-damaged buildings subjected to aftershocks

The seismic response of mainshock-damaged buildings under aftershocks is an important topic in terms of the lateral response of damaged structures. The majority of current seismic design standards just consider a single earthquake (mainshock/design earthquake) and they don’t take into account the influence of aftershocks on the seismic design process. The aftershocks could have significant effects on the seismic response of mainshock-damaged structures. This situation was reported in some of the previous earthquake events in which the aftershocks caused additional damage to the structures. In this study, the fragility curves for structural and non-structural Drift-Sensitive Components (DSCs) and Acceleration-Sensitive Components (ASCs) of two low-rise mainshock-damaged moment resisting steel and reinforcement concrete buildings under the effect of aftershocks with different intensities were presented. The intensity of the mainshocks was adjusted until the intact buildings experienced three levels of damage states including slight, moderate and extensive damage states. After that, the fragility curve of the structural and non-structural components of the mainshock-damaged buildings under the effect of aftershocks was evaluated by the Incremental Dynamic Analysis (IDA). The results show that the effect of aftershocks on the probability of damage to structural and non-structural components of mainshock-damaged structures is related to the level of the initial damage. For slightly and moderately mainshock-damaged buildings, the probability of exceedance of the damage under aftershocks is relatively similar to the intact buildings, however, the aftershocks significantly increase the probability of damage to the extensively mainshock-damaged buildings. Although extensive initial damage causes a significant increase in the probability of damage to non-structural DSCs, the damage probability of non-structural ASCs remains relatively as similar to intact buildings. Regarding the HAZUS manual, the results show that the probability of damage exceedance of the structural components is higher than non-structural ASCs, however, the opposite observation was reported from the previous earthquakes. Therefore, in this study, four levels of damage threshold for non-structural ASCs are proposed.

Research on column overdesign factor of reinforced concrete frame structures in the 2022 Ms 6.8 Luding earthquake

The strong column-weak beam failure mode of reinforced concrete (RC) frame structures is one of the most important targets of structural seismic design and is primarily realized by a reasonable column overdesign factor (COF). However, most RC frame structures in previous earthquakes were often subjected to strong beam-weak column failure modes. To address this issue, the RC frame with a strong column-weak beam failure mode and a typical strong beam-weak column RC frame in the 2022 Ms 6.8 Luding earthquake were intensively studied in this study. The differences between the two failure modes of the RC frame structure were comparatively analyzed at both the overall structure and member levels. A numerical simulation was conducted to obtain the structural response under actual ground motion. Finally, a probabilistic analysis method was adopted to process the COF data of the RC frame joints. The results indicate that the structural safety redundancy of the RC frame with the undesired failure mode cannot be fully utilized, whereas the RC frame with the strong column-weak beam failure mode allows more structural members to participate in the energy dissipation through a complex redistribution mechanism of internal forces. Damage to the infill wall further mitigates the degree of damage to the main structure and reduces the risk of soft-story failure. The COF of the actual RC frame structure shows a non-uniform distribution, and it is recommended that the COF be higher than 1.5 for the seismic design of the structure following the Chinese code.

Premonitory Earthquakes Clustering Process in an Equivalent Dimensions Space before the 2017 Mw 8.2 Tehuantepec, Mexico, Mainshock

Abstract The transformation to equivalent dimensions, an innovative methodology to investigate earthquake clustering, is engaged in tracking the preparatory process of the 2017 Mw 8.4 Tehuantepec, Mexico, mainshock. The studied seismic series comprises earthquakes from 1999 to May 2020 in an area extended three times more than the main rupture length. We parameterized each earthquake by its magnitude, the waiting time for its occurrence, that is, the time since the previous earthquake after which this earthquake occurred, and the epicentral offset from the previous earthquake, that is, the distance of the epicenter of this earthquake from the epicenter of the previous earthquake. After transformation to equivalent dimensions, these three parameters became mutually comparable. The average distance between earthquakes in the space of these three transformed parameters was used to determine the degree of event clustering. We calculated this distance in data windows moving in time, each consisting of 100 events. The average distance exhibited a consistent upward trend from ten to two years before the mainshock. Then, it declined until the mainshock. This precursory up–down signal was highly significant statistically. We showed that the detected time changes of the average distance resulted from the evolution of the earthquake clustering in the space of their parameters.

Probabilistic prediction of post-earthquake rubble distribution range for masonry structures

In previous earthquakes, masonry structures have experienced large-scale localized or total collapse, and the rubble distribution formed after the collapse has had a significant impact on the post-earthquake transportation system. This paper analyses the rubble distribution characteristics of masonry structures on different floors (3, 5, and 7 floors) under 22 FEMA-recommended far-field ground motion records. A range model for debris distribution for masonry structures considering peak ground accelerations and building height is first proposed. Then, the risk range model for masonry structure rubble distribution was developed by considering the fragility of building collapse and the uncertainty of rubble distribution. Based on the model, it is able to predict the range of rubble distribution and the risk range of rubble distribution for buildings of different heights under different peak ground accelerations, and calculate the acceptable rubble distribution distance according to the exceeding probability of rubble appearing within a certain distance. It can provide data support for government decision makers to formulate emergency plans for post-earthquake transportation systems before the earthquake.

The Largest Geodetic Coseismic Assessment of the 2020 Mw = 6.4 Petrinja Earthquake

On 28 December 2020, the area of the city of Petrinja was hit by two strong earthquakes of magnitudes 5.0 and 4.7 on the Richter scale, and the following day, 29 December 2020, the same area was hit by an even stronger earthquake of magnitude 6.2. It was one of the two strongest instrumentally recorded earthquakes that hit the territory of the Republic of Croatia in the last hundred years, and the strongest earthquake in the Banovina area after the great earthquake in 1909. Increased seismic activity in this area is caused by two vertical strike–slip faults, Pokupski and Petrinjski. This article aims to determine the displacements of the Earth’s crust caused by seismic activity in this area using GNSS measurements and InSAR techniques and comparing their results. Our study showed that horizontal coseismic displacements of 20 cm and more were limited to a radius of 20 km from the epicenter, with a maximum displacement of around half a meter. Considering the original plate tectonic movements of the region and the time elapsed since the previous earthquake of similar magnitude, the geodynamic movements of the Dinarides area are in substantial part sudden displacements associated with earthquakes.

Finding Earthquake Patterns with Time Series and Regression Models

Due to their unpredictability, earthquakes are certainly the most dangerous natural disasters. Scientists have long struggled to understand the movement of tectonic plates, as they occur at depths that cannot be directly seen and occur extremely slowly, at a rate that results in possibly one every thousand years between two adjacent plates. What if we could take a different approach, however? What if we could leverage the recent advances in machine learning to close this gap? That is exactly what we aimed to do in our research, with the question of whether various factors related to earthquakes, such as their magnitude and time of occurrence, could be determined through the analysis of years of historical data. This was conducted through the analysis of a dataset which contained records of all major earthquakes (magnitude 5.5 or higher) from 1900-2023. The library scikit-learn was used for various regression models, such as linear regression, random forest regression, and lasso regression, and the library FB prophet was used for time series forecasting, a method used to analyze patterns in previous earthquakes to predict new ones. Our conclusions were that, with some degree of error, the magnitude of an earthquake can be determined based on location/time and the time of occurrence can be pinpointed to specific days of the week as well as months.

Directionality characteristics of horizontal response spectra from the 2022 Mw 6.9 Chihshang, Taiwan earthquake

Horizontal earthquake ground motion intensity, and specifically response spectral ordinates, vary with orientation. This phenomenon is usually referred to as ground motion directionality and can be separated into two aspects: the orientation where the maximum spectral response occurs and the variation of response spectral ordinates as the orientation moves away from the orientation of maximum spectral response. This work studies both aspects using the recent 2022 Mw 6.9 Chihshang, Taiwan earthquake, which was recorded by a dense network of strong motion stations with various geological and topographical settings. The mean variation of response spectral ordinates with orientation is found to be slightly more significant than that of previous shallow crustal earthquakes in active tectonic regimes. Moreover, the orientation of maximum spectral response is found to be close to the transverse orientation, which is perpendicular to the orientation at a given site that points to the earthquake epicenter, confirming prior observations made for strike-slip earthquakes. These results suggest that the location of a site relative to the seismic source could be used to modify the outputs of ground motion models to estimate spectral responses at specific horizontal orientations.

Earthquake-induced paleo-landslides in the Tehran Region and its role in assessing the seismic hazard, Iran

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.

Importance of building inspection on the seismic response of a severely damaged RC structure during the February 6, 2023 Kahramanmaraş earthquake sequence

Large magnitude February 6, 2023 earthquakes in Türkiye created a devastating effect on the building stock on a vast region. For earthquakes of this magnitude, severe damage and collapses are indispensable to the old building stock with deficiencies certified in previous earthquakes. But unexpectedly, the newly constructed buildings that were designed by recent version of Turkish Building Seismic Code (TBEC 2018) also experienced severe damage. After conducting site investigations on one of the recently constructed and severely damaged RC building, a detailed numerical study was performed to identify the reasons for the observed seismic damage. This study pinpoints the main cause of such damage due to lack of thorough building inspections during construction to ensure the implementation of the seismic reinforcement detailing specified in blueprints for providing required ductility, as revealed by field investigations. Additionally, it identifies potential issues stemming from a lack of full comprehension of the seismic design philosophy within the code. The existing design pushes the limits on the axial load level on slender column elements and fall short in capturing the soft story irregularity. Although there is a soft base story in the investigated building, using structural walls only in one direction with moderately confined boundary zones increased its vulnerability. This example shows that in Türkiye, where seismic activity is very high and quite lethal, seismic design codes should set stricter limits and measures, and building inspection system must be strictly enforced.

Development of seismic fragility curves for hospital buildings using empirical damage observations

Fragility curves are widely recognized as an essential tool for assessing and projecting asset damage, vulnerability, and seismic risk. The technical literature provides different fragility curves for residential buildings that exhibit unique characteristics for different categories of buildings, however, comparatively fewer curves are available for hospital buildings. The specific design criteria for hospital buildings necessitate specialized fragility curves for them. In the current study, a set of empirical fragility curves for hospitals have been developed utilizing the data of 341 damaged hospital buildings in previous earthquakes. The peak ground acceleration of the occurred earthquake events in the location of the considered hospitals is utilized as earthquake intensity measure. Fragility curves are developed for the three categories of low-rise concrete moment frame, medium-rise concrete moment frame, and masonry hospital buildings. Due to the lack of appropriate available data, the fragility curves of masonry hospitals are developed by merging the collected data with the fragility curves acquired from the existing literature. The creation of fragility curves for non-structural components of hospitals is another contribution of this study. Finally, a comparison of the fragility curves derived in the current study with those documented in existing research papers is provided.

In-situ rock shattering and strain localization along a seismogenic fault in dolostones (Monte Marine fault, Italian Central Apennines)

In-situ shattered rocks are often associated with seismogenic fault zones, but their mechanism of formation is still matter of debate, partly because of the limited number of field studies. Here we describe the characteristics of in-situ shattered rocks distribution along the NW-SE-striking seismogenic Monte Marine Fault (MMF) in the Italian Central Apennines. In the studied area, the MMF cuts through Mesozoic carbonates, is exhumed from <3 km depth and consists of two >5 km-long major hard-linked segments with normal kinematics. The linkage between the two fault segments occurs along a ∼2 km-long step-over zone with E-W trending faults and oblique-slip kinematics. To the northwest, fault-related shear deformation is localized in a ∼5 m-thick cataclastic fault core and off-fault deformation is dominated by in-situ shattered rocks up to ∼40 m-thick. Instead, in the step-over zone to the southeast, the in-situ shattered rocks are up to ∼500 m thick, particularly where MMF crosscuts older low-angle thrust faults.We integrated detailed field structural surveys with microstructural and grain size distribution analyses of the fault rocks to assess the mechanism of (1) formation of in-situ shattered rocks and, (2) progressive localization of shear deformation along the MMF. The obtained results, after the viability of several formation mechanisms (mechanical models) have been reviewed, support the hypothesis that the formation of in-situ shattered rocks was associated with the propagation of (multiple) seismic ruptures (mainshocks and aftershock sequences) within a mechanically heterogeneous fault zone. Heterogeneity is due to the occurrence of preexisting damage related to previous earthquakes, but also inherited from the older low-angle thrust faults. Therefore, we suggest that the origin of these shattered rocks is more compatible with seismic related processes than only with quasi-static fault growth models. On the other hand, the cataclastic fault core derived from the progressive accommodation of shear deformation within the in-situ shattered rock volumes during several seismic cycles. We conclude that the large volumes of in-situ shattered rocks are the result of seismic-related dissipative processes in a geometrically and mechanically heterogeneous fault zone. In this scenario, large volumes of in-situ shattered rocks are compliant low velocity zones which can influence the propagation of earthquake ruptures.

The relationship between kinematics and fault geometry for surface coseismic ruptures on across-strike faults: New observations of slip vectors and displacements along the Pisia and Skinos faults from the 1981 Eastern Gulf of Corinth, Greece earthquakes

The relationships between kinematics and fault geometry for the coseismic ruptures from the 24th and February 25, 1981 earthquake sequence in the eastern Gulf of Corinth (Ms 6.7 and 6.4) are analysed. The two earthquakes ruptured faults located across strike rather than along strike as typifies other earthquake sequences. In detail, surface ruptures formed on the sub-parallel Pisia and Skinos Faults, with an 8 km along-strike overlap zone, separated across strike by < 2 km. The largest coseismic offsets occurred in the overlap zone. The 41-year-old ruptures are still well preserved as bedrock fault plane lichen-free stripes and colluvial ruptures, allowing detailed structural mapping at 213 rupture localities. A comparison between our measurements and Jackson et al. (1982) showed no overall consistent signal of post-seismic slip as some of our measurements were greater and some smaller than those recorded in 1981. The ruptures produced a single maximum asymmetric profile (Pisia: maximum throw of 223 cm) and a double maxima profile (Skinos: maximum throw of 109 cm and 130 cm). The shapes of the profiles differed in previous earthquakes on these faults, as evidenced by an older lichen-free stripe, implying non-characteristic earthquakes. Summing the two overlapping throw profiles across-strike reveals a single maximum symmetric bell-like profile. Using the above observations on coseismic offsets, kinematic information, and the geometry of faults, a rupture scenario has been proposed in terms of fault bends and corrugation orientations which suggests that parts of each fault may have ruptured in each earthquake.

Probabilistic forecast of next earthquake event in Makran subduction zone using Weibull distribution

Earthquake is the most lethal type of natural disaster. Researchers have been working to develop precise earthquake prediction methods to save lives. A statistical investigation is an effective earthquake prediction method because they offer more details about the seismic risk or hazard issue. This study utilizes seismic data from the Makran subduction zone from 1934 to 2017. Probability distributions may be employed to assess the risk of seismic events and earthquake occurrence probability. This work estimates the probability of the next major event in the Makran subduction zone through Weibull distribution by considering strong earthquakes with a magnitude (Mw ≥ 6) in the intervals (in years) between two consecutive earthquakes. The probabilities of the forthcoming seismic event have been estimated based on the previous earthquake record, pictorially. The calculated parameters of the Weibull distribution for the Makran subduction zone may help to forecast the probabilities of a strong earthquake and describe the pattern of earthquake average return time. The calculated probability for the Weibull distribution reaches 0.92 after ten years since the last strong earthquake in 2021, indicating that the Weibull distribution within and around the present research area in 2031 will be 92%.