Pseudo-spectral Acceleration Research Articles

Spatial Correlation of Peak Ground Motions and Pseudo Spectral Acceleration Based on the Iranian Multievent Datasets

ABSTRACT Spatial correlations of peak ground and pseudo spectral acceleration are estimated as a function of intersite separation distance and natural vibration periods. More than 2286 three-component records from 461 Iranian earthquakes are employed to evaluate the intra-event residual correlation based on multiple earthquakes, considering both local and regional ground motion prediction equations (GMPEs). A correlation analysis is carried out through semivariogram as a powerful geostatistical tool. The results show the overall trend of correlation range increases as a function of structural period that appear consistent with previous researches. The average decay of correlation in Iran is slightly more rapid than that of California.

Ground-Motion Intensity Measure Correlations on Interface and Intraslab Subduction Zone Earthquakes Using the NGA-Sub Database

ABSTRACTThe NGA-Sub (subduction zone earthquake) database developed by the Pacific Earthquake Engineering Research center is used to derive new correlation coefficients for a number of ground-motion intensity measure (IM) parameters from ground motions in subduction zone earthquakes, considering both interface and intraslab tectonic settings. The IMs include peak ground acceleration, pseudospectral accelerations with periods from 0.01 to 10 s, Arias intensity, cumulative absolute velocity, peak ground velocity, and significant duration. Comparisons of the estimated correlation coefficients for ground motions from the interface and intraslab tectonic settings generally show a good agreement. Our estimations are also in good agreement with correlation coefficients estimated in previous studies that used ground motions from shallow crustal earthquakes, supporting the concept that any variation in correlation coefficients comes from spectral shape (i.e., the distribution of peaks and troughs) rather than tectonic region. This study also explores the influence of parameters such as magnitude, distance, and site conditions on the estimated correlation coefficients. We did not find apparent trends of the correlation coefficients with respect to these parameters. Finally, we propose analytical models to estimate correlation coefficients between the IMs explored in this study, considering both subduction interface and intraslab tectonic settings.

Conditional Ground-Motion Models for Horizontal Peak Ground Displacement for Active Crustal Regions

ABSTRACTGround-motion models (GMMs) are developed for peak ground displacement (PGD) and for bandlimited PGD based on strong-motion data that has been filtered as part of standard processing and the total PGD that includes the tectonic deformation as well as the vibratory ground motion. For the bandlimited PGD, we develop conditional ground-motion models (CGMMs) using subsets of the Pacific Earthquake Engineering Research Center Next Generation Attenuation-West2 Project (NGA-W2) database and the National Center for Research on Earthquake Engineering Taiwan Senior Seismic Hazard Analysis Committee level 3 project database. The CGMM approach includes the observed pseudospectral acceleration (PSA(T)) as an input parameter in addition to magnitude and distance. The period of the PSA(T) is used as an input parameter; it is magnitude dependent and is based on the period for which there is the highest correlation between the ln(PGD) and ln(PSA(T)). Two CGMMs are developed: a global model based on the NGA-W2 data and a region-specific model for Taiwan. The conditional PGD models are combined with traditional GMMs for PSA(T) values to develop GMMs for both the median and standard deviation of PGD without the dependence on PSA. A second set of PGD GMMs are developed to correct for two factors: the effect of the high-pass filtering from standard record processing and the stronger large magnitude (M>6.5) scaling due to tectonic deformation. For magnitudes greater than 7, the PGD values from the total PGD GMMs are 2–5 times larger than the bandlimited PGD values based on the strong-motion data sets, but the increase is at very long periods. The appropriate PGD model to use, bandlimited PGD or total PGD, depends on the period range of interest for the specific engineering application.

Effects of 2-D random velocity perturbations on 2-DSHshort-period ground motion simulations in the basin of Nice, France

SUMMARYSome geological configurations, like sedimentary basins, are prone to site effects. Basins are often composed of different geological layers whose properties are generally considered as spatially homogeneous or smoothly varying. In this study, we address the influence of small-scale velocity fluctuations on seismic response. For this purpose, we use the spectral element method to model the 2-D SH wave propagation on a basin of 1.1 km long and ≈ 60 m deep, representing a 2-D profile in the city of Nice, France. The velocity fluctuations are modelled statistically as a random process characterized by a Von Karman autocorrelation function and are superimposed to the deterministic model. We assess the influence of the amplitude and correlation length of the random velocities on the surface ground motion. We vary the autocorrelation function’s parameters and compute seismic wavefields in 10 random realizations of the stochastic models. The analyses of our results focus on the envelope and phase differences between the waveforms computed in the random and deterministic models; on the variability of ground motion intensity measures, such as the peak ground velocity, the pseudo-spectral acceleration response; and the 2-D basin response (transfer function). We find that the amplitude of fluctuations has a greater effect on the ground motion variability than the correlation length. Depending on the random medium realization, the ground motion in one stochastic model can be locally amplified or deamplified with respect to the reference model due to the presence of high or low velocity contrasts, respectively. When computing the mean amplification of different random realizations, the results may be smaller than those of the reference media due to the smoothing effect of the average. This study highlights the importance of knowing the site properties at different scales, particularly at small scales, for proper seismic hazard assessment.

Simulation-Based Seismic Hazard Assessment Using Monte-Carlo Earthquake Catalogs: Application to CyberShake

ABSTRACTThe use of numerical simulations in probabilistic seismic hazard analysis (PSHA) has achieved a promising level of reliability in recent years. One example is the CyberShake project, which incorporates physics-based 3D ground-motion simulations within seismic hazard calculations. Nonetheless, considerable computational time and resources are required due to the significant processing requirements imposed by source-based models on one hand, and the large number of seismic sources and possible rupture variations on the other. This article proposes to use a less computationally demanding simulation-based PSHA framework for CyberShake. The framework can accurately represent the seismic hazard at a site, by only considering a subset of all the possible earthquake scenarios, based on a Monte-Carlo simulation procedure that generates earthquake catalogs having a specified duration. In this case, ground motions need only be simulated for the scenarios selected in the earthquake catalog, and hazard calculations are limited to this subset of scenarios. To validate the method and evaluate its accuracy in the CyberShake platform, the proposed framework is applied to three sites in southern California, and hazard calculations are performed for earthquake catalogs with different lengths. The resulting hazard curves are then benchmarked against those obtained by considering the entire set of earthquake scenarios and simulations, as done in CyberShake. Both approaches yield similar estimates of the hazard curves for elastic pseudospectral accelerations and inelastic demands, with errors that depend on the length of the Monte-Carlo catalog. With 200,000 yr catalogs, the errors are consistently smaller than 5% at the 2% probability of exceedance in 50 yr hazard level, using only ∼3% of the entire set of simulations. Both approaches also produce similar disaggregation patterns. The results demonstrate the potential of the proposed approach in a simulation-based PSHA platform like CyberShake and as a ground-motion selection tool for seismic demand analyses.

Simulation-Based Seismic Hazard Assessment Using Monte-Carlo Earthquake Catalogs: Application to CyberShake

ABSTRACTThe use of numerical simulations in probabilistic seismic hazard analysis (PSHA) has achieved a promising level of reliability in recent years. One example is the CyberShake project, which incorporates physics-based 3D ground-motion simulations within seismic hazard calculations. Nonetheless, considerable computational time and resources are required due to the significant processing requirements imposed by source-based models on one hand, and the large number of seismic sources and possible rupture variations on the other. This article proposes to use a less computationally demanding simulation-based PSHA framework for CyberShake. The framework can accurately represent the seismic hazard at a site, by only considering a subset of all the possible earthquake scenarios, based on a Monte-Carlo simulation procedure that generates earthquake catalogs having a specified duration. In this case, ground motions need only be simulated for the scenarios selected in the earthquake catalog, and hazard calculations are limited to this subset of scenarios. To validate the method and evaluate its accuracy in the CyberShake platform, the proposed framework is applied to three sites in southern California, and hazard calculations are performed for earthquake catalogs with different lengths. The resulting hazard curves are then benchmarked against those obtained by considering the entire set of earthquake scenarios and simulations, as done in CyberShake. Both approaches yield similar estimates of the hazard curves for elastic pseudospectral accelerations and inelastic demands, with errors that depend on the length of the Monte-Carlo catalog. With 200,000 yr catalogs, the errors are consistently smaller than 5% at the 2% probability of exceedance in 50 yr hazard level, using only ∼3% of the entire set of simulations. Both approaches also produce similar disaggregation patterns. The results demonstrate the potential of the proposed approach in a simulation-based PSHA platform like CyberShake and as a ground-motion selection tool for seismic demand analyses.

Site effect and microzonation of the Jizan coastal area, southwestern Saudi Arabia, for earthquake hazard assessment based on the geotechnical borehole data

Ninety-one geotechnical boreholes were drilled throughout Jizan City and the subsoil profiles were modeled. The SPT-N values were corrected to the N60 parameter. Then, the calculated shear wave velocity for 30 m depth (Vs30) varies between 196.086 and 589.931 m/s. Moreover, the site soil was classified into two of soil classes detected. Thereafter, the site response with SMSIM software is assigned at all borehole locations using Vs30, predominant frequency, and corresponding amplitude amplification factor. The estimated amplification factor varied between 1.6 and 18.2, reflecting the significant difference in the thicknesses of soil. The values of high amplification extend in a north–south strip to the west indicating very soft/loose sediments with a considerable thickness. Higher fundamental frequency values extend due north along the coast until the Ash-Shati and Ar-Rawabi districts verifying the compacted sediments. The peak ground acceleration (PGA) has been estimated for 91 borehole sites at bedrock level in the Jizan area using Mw 6.25 earthquake magnitude. This PGA was used to generate an ArcGIS contour map. The values of the PGA for the bedrock vary between 4.8 and 10.7 cm/s2. Moreover, PGA is computed at the ground surface level, where it varies between 7.7 and 32.0 cm/s2. Finally, the ground motion response spectra were also estimated with 5% critical damping for the locations of all of the boreholes. The pseudo-spectral acceleration (PSA) and its corresponding frequency/period were calculated for the 91 borehole locations. The values of the maximum PSA ranged between 17 and 103 cm/s2, covering the western zone of the Jizan study area. Furthermore, the PSAs were computed for 1.5, 3, 5, 8, and 10 Hz at 91 locations, and then contoured using the ArcGIS package. This frequency range from 1.5 to 10 Hz represents the range in the natural frequencies for tall to low-rise buildings.

A Response Spectral Ratio Model to Account for Amplification and Attenuation Effects in the Atlantic and Gulf Coastal Plain

ABSTRACT We used our previously published Lg-wave spectral ratio model to develop a model of pseudospectral acceleration (PSA) response ratios at sites in the Atlantic and Gulf Coastal Plain, relative to a reference site condition defined as the mean response for site locations outside the Coastal Plain. The model is strongly dependent on sediment thickness. The results of this study can be used to predict PSA response, for linear behavior, at sites in the Atlantic or Gulf Coastal Plain with a known thickness of Coastal Plain sediment, given a ground-motion model for reference site conditions outside the Coastal Plain region of the central and eastern United States.

Seismic hazard assessment for the proposed site of electric power plant: Comprehensive approach

Al-Sokhna area has been selected for installation one of the electric power plants along the Cairo-Suez Road. Unfortunately, this area lies within small-moderate seismicity area where some destructive earthquakes (>5), great number of earthquakes with magnitudes of less than 5 have been recorded. Through this work, earthquake events within a circle of 300 km radius around the selected site have been gathered, refined, and the affecting earthquake prone zones were recognized as; southern Gulf of Suez, Dahshour and Gulf of Aqaba source, Beni Suef and Sohag-Assuit zones however Dahshour zone is the nearest to the proposed site. The values of Peak Ground Acceleration have been assessed using deterministic and stochastic hazard approaches as 37.63 and 38.4 cm/sec2 respectively. Moreover, the pseudospectral acceleration (PSA) reaches 142, 96 and 74 cm/sec2 at damping values of 2%, 5% and 10% of the critical damping where the predominant period about 0.1 s at the selected site. These results have to be considered by policy and decision-makers to design more earthquake resistant structures at the selected site.

Seismic attenuation model for data gap regions using recorded and simulated ground motions

In this study, seismic attenuation model is derived using recorded and simulated ground motions covering the data gap region of the Indo-Gangetic Plains (IGP), employing artificial neural networks (ANN) methodology. Four independent variables moment magnitude (Mw), focal depth, epicentral distance (Repi), and average shear wave velocity up to 30 m depth (Vs30) are selected to predict peak ground acceleration (PGA) and pseudo-spectral acceleration (PSA) (5% damping) between periods 0.01 to 4 s (twenty-five periods in total), utilizing 926 recordings (PESMOS, CIGN and synthetic database). A feed-forward ANN with Levenberg–Marquardt training algorithm is employed for training the network of input and output dataset. The optimal network architecture obtained in this study consists of 4–9–26 input, hidden and target nodes, respectively. In spite of the absence of presumed functional dependencies in ANN methodology, our model captured a number of sound physical features of earthquake ground motion: magnitude scaling, attenuation with distance and radiation damping. Further, the performance of the model is measured by the standard deviation of the error, σ(e), and compared with the four widely used conventional GMPEs applicable for IGP region of India. The standard deviations for our model varied between 0.208 and 0.263 which is less than the classical GMPEs at all twenty-six periods of PSA. Finally, the ANN model performance is compared with recorded ground motions at four stations and conventional GMPEs, and the results affirm that this model is competent to predict the response spectrum with good accuracy for IGP region.

Seismic Analysis of Single Unit Tunnel Form Building Subjected to In-Plane Lateral Cyclic Loading Using Ruaumoko 2D Programme

Seismic effect to the tunnel form building (TFB) will vary depending on the location of the epicentre, magnitude and frequency of the seismic event. This effect can be mitigated by implementing a seismic analysis using the Ruaumoko 2D programme. The seismic analysis was conducted to examine the safety level of the TFB when it was subjected to 10 previous seismic events. The analysis emphasized the in-plane direction of lateral cyclic loading. The 10 selected seismic excitations were Pacoima Dam, El Centro North-South and East-West, Mexico City, Ranau, Lahad Datu, Kunak, Batu Niah, Manjung and Bukit Tinggi. The analysis results of tunnel form building (TFB) in terms of spectral displacements, earthquake excitations, pseudo-spectral acceleration and deformed shape of single unit tunnel form building obtained in this study. Based on these analyses, tunnel form building (TFB) can only withstand low seismic loading with far-field earthquakes. When subjected to a seismic load greater than 5 Richter Scale and near field excitation, tunnel form building will not safe to be occupied.

A Time–Frequency Representation Model for Seismic Ground Motions

ABSTRACTA probabilistic model of the time–frequency power spectral density (TFPSD) is presented. The model is developed, based on the time–frequency representation of records from strike-slip earthquakes, in which the time–frequency representation is obtained by applying the S-transform (ST). The model for the TFPSD implicitly considers the amplitude modulation and frequency modulation for the nonstationary ground motions; this differs from the commonly used evolutionary PSD model. Predicting models for the model parameters, based on seismic source and site characteristics, are developed. The use of the model to simulate ground motions for scenario seismic events is illustrated, in which the simulation is carried out using a recently developed model that is based on the discrete orthonormal ST and ST. The illustrative example highlights the simplicity of using the proposed model and the physical meaning of some of the model parameters. A model validation analysis is carried out by comparing the statistics of the pseudospectral acceleration obtained from the simulated records to those obtained using a few ground-motion models available in the literature and considered actual records. The comparison indicates the adequacy of the proposed model.

A note on spectral velocity approximation at shorter intermediate periods

It is common to use the design pseudo spectral acceleration (PSA) spectrum together with a modal combination rule to estimate the peak linear seismic response of a structural system. Some of the modal combination rules proposed so far require an accurate estimation of spectral velocity (SV) spectrum consistent with the given design PSA spectrum in order to account for modal correlations in a simple manner. The traditional pseudo spectral velocity (PSV) approximation of SV ordinates is reliable only for the velocity-sensitive region of the spectrum. More reliable approximations have therefore been developed in the recent years for the acceleration-sensitive and displacement-sensitive regions. In this work, the approximation developed for the acceleration-sensitive region is proposed to be applied on a greater range of periods, involving the shorter periods of the velocity-sensitive region, for a more accurate estimation of the SV spectrum. Regression equations are developed to predict the limiting period of the extended range by using the information available from the given PSA spectrum. A correction factor is also proposed to be applied to the SV estimates in order for those to have a smooth transition near the limiting period.

Bayesian inference of a physical seismological model for earthquake strong-motion in south Iceland

Earthquake ground motion prediction in Iceland where strong-motion data is scarce poses a challenge as empirical ground motion models (GMM) developed from data in other regions systematically fail to capture the consistently large near-fault peak amplitudes and their rapid attenuation with distance from the earthquake source. Therefore, regional GMMs must be constructed but due to the limited data, and none above Mw6.5, earthquake source scaling is unconstrained at larger magnitudes. Instead, physics-based GMMs should be applied based on realistic earthquake source modeling. For that purpose, a seismological model constructed around the specific barrier model (SBM) has been calibrated in the context of the stochastic method using random vibration theory, to earthquake high-frequency strong-motions in the South Iceland Seismic Zone. The SBM is used as it provides a physically consistent and efficient description of the heterogeneous faulting processes that are responsible for the generation of high-frequency waves. On the basis of the concise point-source representation of radiated spectra from N subevents of the SBM the pseudo-spectral accelerations were modeled and compared with that of data in the spectral domain. Backwards model selection was then carried out using Bayesian inference with Monte Carlo simulations and Markov Chains. The number of parameters in the model inference was reduced to obtain stable Markov chains and posterior probability density functions for each parameter, eliminating parametric cross-correlations to the extent possible. The seismological model has been shown to be unbiased with respect to strong-motions in the SISZ, with a total standard deviation of 0.216 (common logarithm), with only a minor contribution from inter-event variability, suggesting a relatively uniform character of SISZ earthquake strong-motions. We showcase the application of the SBM extended into a finite-fault and model the three Mw6.3-6.5 earthquakes in the dataset, allowing subevents of varying sizes to populate the fault plane and provide a more realistic earthquake source and acceleration ground motion time history modeling. The time domain results are shown to capture the essential characteristics of the ground motions of the three largest earthquakes in the dataset. We present therefore the SBM as a physically consistent source model of SISZ earthquakes for the generation of synthetic strong-motion time histories or peak parameters, with potential applications in scenario simulations and probabilistic or deterministic seismic hazard assessment.

Efficiency of ground motion intensity measures with earthquake-induced earth dam deformations

In a seismic hazard analysis (SHA), the earthquake loading level should be predicted for one or more ground motion intensity measures (IMs) that are expected to relate well with the engineering demand parameters (EDPs) of the site. In this study, the goal was to determine the IMs that best relate to embankment dam deformations based on nonlinear deformation analysis (NDA) results of two embankment dams with a large suite of recorded ground motions. The measure utilized to determine the “best” IM was standard deviation in the engineering demand parameter (e.g., deformation) for a given IM, also termed “efficiency.” Results of the study demonstrated that for the NDA model used, Arias intensity (AI) was found to be the most efficient predictor of embankment dam deformations. In terms of pseudo-spectral acceleration (PSA)-based IMs, the PSA at short periods and then in the general range of the natural period of the dams was seen to be the most efficient IM, but was in almost all cases not as efficient as AI.

Spatial Correlation of Peak Ground Motions and Pseudo-Spectral Acceleration Based on the Sarpol-e-Zahab Mw 7.3, 2017 Earthquake Data

Ground motion intensity measures and structural responses are correlated in nearby sites. The value of this correlation relies on some parameters such as the local geology and distance between the two sites and the natural period of structures, particularly, when lifeline systems or distributed structures are of concern, the issue becomes more important. In this study, the spatial correlation of peak ground acceleration and Spectral Acceleration are evaluated as a function of inter-site separation distance for the Mw7.3 Sarpol-e-Zahab earthquake. On 12 November 2017 a large earthquake occurred near the western border of Iran. The epicenter of the earthquake was reported at 34.77 N and 45.76 E. Here, 192 pairs of horizontal components from the above-mentioned event and 35 of its larger aftershocks with magnitude ranging from Mw 4.0 to 7.3 are employed to evaluate the intra-event residual correlation by considering two Ground Motion Prediction Equations (GMPEs) proposed by Akkar and Bommer [2010] and Zafarani et al. [2017]. A correlation analysis is carried out through semivariogram as a powerful geostatistical tool. As a skeleton for correlation modeling, a kind of exponential model is used. According to the proposed model, the results show that the overall trend of correlation Range depends on spectral period. The results demonstrate that there is strong spatial correlation in the proposed model obtained from the Sarpol-e- Zahab ground motions. The model provided in this study could be employed in earthquake engineering implements such as Shakemaps [Wald et al., 1999] whenever spatial correlation models are required.

Spatial Correlation of Peak Ground Motions and Pseudo-Spectral Acceleration Based on the Sarpol-e-Zahab Mw 7.3, 2017 Earthquake Data

Spatial Correlation of Peak Ground Motions and Pseudo-Spectral Acceleration Based on the Sarpol-e-Zahab Mw 7.3, 2017 Earthquake Data

Site-specific probabilistic seismic hazard assessment for proposed smart city, Warangal

In the present work, a probabilistic seismic hazard analysis has been performed for the newly formed Warangal Urban District, Telangana, India. The standard Cornell–McGuire method has been adopted considering different seismic zones. The area of influence chosen is having a radius of 500 km with NIT Warangal as the centre. An earthquake catalogue for the period 1800–2016 AD has been compiled and homogenized using global empirical relationships. Alternative models have been considered for seismic zoning scenario, completeness analysis of earthquake catalogue, maximum magnitude and ground-motion prediction equations (GMPEs) in the logic tree approach by assigning normalized weighs to each model, thereby reducing the epistemic uncertainty. Seismic hazard has been presented as the peak ground acceleration (PGA) and pseudo-spectral acceleration (PSA) maps at 5% damping for spectral periods T = 0.05, 0.1, 0.5 and 1 s at 2% and 10% probability of exceedance in 50 yrs period. The results obtained were compared with IS: 1893-1 (2016) (Criteria for earthquake resistance design of structures, Part-I. Bureau of Indian Standard, New Delhi, 2016) and NDMA (2011) (Development of probabilistic seismic hazard map of India, Technical Report of the Working Committee of Experts (WCE), National Disaster Management Authority (NDMA). Govt. of India, New Delhi, 2011) and they were found to be in excellent agreement. The profile of shear wave velocity (VS) was obtained by using the multichannel analysis of surface wave (MASW) method. The site was characterized as per NEHRP manual based on VS. The obtained shear wave velocity values are used in performing the 1-D ground response. A higher PGA has been observed at surface level when compared with the PGA values obtained at rock level suggesting seismic wave amplification due to subsoil condition.

Ground motion prediction equation for crustal earthquakes in Taiwan

We develop a ground motion prediction equation (GMPE) for estimating horizontal ground motion amplitudes caused by crustal earthquakes, based on an integrated data set that includes strong motion recordings mainly from Taiwan earthquakes and only from large magnitude earthquakes in the NGA-West2 database. This GMPE is developed for probabilistic seismic hazard analysis study, which is introduced as a part of Taiwan Senior Seismic Hazard Analysis Committee Level 3 projects. The functional form developed by Chiou and Youngs was carefully studied to determine the key modeling parameters needed to regress against ground motion in the target region. Using this functional form, the GMPE achieves considerable improvement over previously developed Taiwan GMPEs. In particular, the use of a high-order function in magnitude scaling enables representation of the saturation effects of large earthquakes. Moreover, consideration of focal mechanisms, depth effects, and dip effects are used to correct the magnitude scaling; consideration of nonlinear site amplification is conditioned on VS30 and reference ground motion on rock; and consideration of basin depth effect is a function of Z1.0 in correlation with VS30. In addition, ground motion data used in this study are not only expanded by more than three times as many earthquakes and records compared with a previous Taiwan model but also provide the metadata of these records that were not available or were previously incomplete. In this study, we compare the proposed model with the NGA-West2 models and discuss the regional difference in ground motion in terms of spectral shape, magnitude scaling, distance scaling, depth scaling, style of faulting, and site effects. We provide median and single standard deviations of peak ground acceleration and 5% damped pseudospectral acceleration response ordinates of the orientation-independent average horizontal component of ground motion (RotD50) for the spectral period of 0.01–10 s.

Probabilistic seismic hazard assessment for some parts of the Indo-Gangetic plains, India

Indo-Gangetic plains are seismically most vulnerable due to the proximity of adjacent great Himalayan earthquakes and thick alluvium deposits of the Ganga River system. As the urbanization on this plain is increasing, there is a need to quantify seismic hazard in the Indo-Gangetic plains (IGPs). IGP also includes major cities with high population density. A probabilistic seismic hazard analysis (PSHA) plays an essential role in ensuring the safety of buildings, bridges and nuclear power stations. A seismic hazard analysis (SHA) was performed deterministically for most of the atomic power stations in India. An attempt has been made to perform PSHA of the part of Indo-Gangetic plains around Narora nuclear power plant (NNPP), accounting for a wide variety of uncertainties associated with SHA. Geological and tectonic features, as well as seismicity distribution around NNPP, are studied in detail, and four source zones are identified according to the geology, seismotectonics and diffuse seismicity. Mmax values for all the source zones based on 300-km distance around NNPP are 7.61 ± 0.54 for Himalaya zone (Zone 1), 6.12 ± 0.54 for Indo-Gangetic Peninsular India (IGPI) East zone (Zone 2), 6.29 ± 0.54 for IGPI Central zone (Zone 3) and 6.38 ± 0.64 for IGPI West zone (Zone 4). The b-value and return period of earthquakes in these zones are also estimated using Kijko–Sellevoll–Bayes model. The hazard curve for peak ground acceleration (PGA) and pseudo-spectral acceleration (PSA) at 0.2 s for the study region is obtained. Hazard map shows a PGA value of 0.0294 g for 100-year return period, 0.0616 g for 475-year return period design-based earthquakes, 0.1033 g for 2475-year return period maximum considered earthquakes, 0.1508 g for 10K-year return period and 0.2598 g for 100K-year return period level at PGA considering all source zones. Similarly, the hazard curve and maps for PSA at 0.2 s are also plotted. According to seismic zonation map of India, most of the study area lies in Zone 4, and the PGA values reported in seismic zonation map and Global Seismic Hazard Analysis Program for the study area range from 0.3 to 0.4 g. The obtained PGA values denote the maximum expected PGA at bedrock level in the study area.