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

2021 ◽  
Author(s):  
Sarah Azar ◽  
Mayssa Dabaghi
Keyword(s):  
Monte Carlo ◽  
Seismic Hazard ◽  
Ground Motion ◽  
Seismic Hazard Assessment ◽  
Computational Time ◽  
Earthquake Catalog ◽  
Earthquake Catalogs ◽  
Earthquake Scenarios ◽  
Simulation Based ◽  
Hazard Curves

ABSTRACT The 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

2021 ◽  
Author(s):  
Sarah Azar ◽  
Mayssa Dabaghi
Keyword(s):  
Monte Carlo ◽  
Seismic Hazard ◽  
Ground Motion ◽  
Seismic Hazard Assessment ◽  
Computational Time ◽  
Earthquake Catalog ◽  
Earthquake Catalogs ◽  
Earthquake Scenarios ◽  
Simulation Based ◽  
Hazard Curves

ABSTRACT The 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.

A Monte Carlo approach to seismic hazard analysis

1999 ◽  
Vol 89 (4) ◽  
pp. 854-866 ◽  
Author(s):  
John E. Ebel ◽  
Alan L. Kafka
Keyword(s):  
Monte Carlo ◽  
Seismic Hazard ◽  
Ground Motion ◽  
Epicentral Distance ◽  
Ground Motions ◽  
Source Parameters ◽  
Parametric Models ◽  
Earthquake Catalog ◽  
Attenuation Relations ◽  
Ground Motion Attenuation

Abstract We have developed a Monte Carlo methodology for the estimation of seismic hazard at a site or across an area. This method uses a multitudinous resampling of an earthquake catalog, perhaps supplemented by parametric models, to construct synthetic earthquake catalogs and then to find earthquake ground motions from which the hazard values are found. Large earthquakes extrapolated from a Gutenberg-Richter recurrence relation and characteristic earthquakes can be included in the analysis. For the ground motion attenuation with distance, the method can use either a set of observed ground motion observations from which estimates are randomly selected, a table of ground motion values as a function of epicentral distance and magnitude, or a parametric ground motion attenuation relation. The method has been tested for sites in New England using an earthquake catalog for the northeastern United States and southeastern Canada, and it yields reasonable ground motions at standard seismic hazard values. This is true both when published ground motion attenuation relations and when a dataset of observed peak acceleration observations are used to compute the ground motion attenuation with distance. The hazard values depend to some extent on the duration of the synthetic catalog and the specific ground motion attenuation used, and the uncertainty in the ground motions increases with decreasing hazard probability. The program gives peak accelerations that are comparable to those of the 1996 U.S. national seismic hazard maps. The method can be adapted to compute seismic hazard for cases where there are temporal or spatial variations in earthquake occurrence rates or source parameters.

scholarly journals Neo-deterministic seismic hazard assessment of Corsica-Sardinia block

2021 ◽  
Author(s):  
Enrico Brandmayr ◽  
Franco Vaccari ◽  
Giuliano Francesco Panza
Keyword(s):  
Seismic Hazard ◽  
Ground Motion ◽  
Hazard Assessment ◽  
Seismic Hazard Assessment ◽  
Earthquake Ground Motion ◽  
Earthquake Catalog ◽  
Hazard Maps ◽  
Source Information ◽  
Deterministic Seismic Hazard ◽  
Seismogenic Nodes

AbstractThe Corsica-Sardinia lithospheric block is commonly considered as a region of very low seismicity and the scarce reported seismicity for the area has till now precluded the reliable assessment of its seismic hazard. The time-honored assumption has been recently questioned and the historical seismicity of Sardinia has been reevaluated. Even more, several seismogenic nodes capable of M5 + have been recognized in the Corsica-Sardinia block exploiting the morphostructural zonation technique, calibrated to earlier results obtained for the Iberian peninsula, which has structural lithospheric affinities with the Corsica-Sardinia block. All this allows now for the computation of reliable earthquake hazard maps at bedrock conditions exploiting the power of Neo Deterministic Seismic Hazard Assessment (NDSHA) evaluation. NDSHA relies upon the fundamental physics of wave generation and propagation in complex geologic structures and generates realistic time series from which several earthquake ground motion parameters can be readily extracted. NDSHA exploits in an optimized way all the available knowledge about lithospheric mechanical parameters, seismic history, seismogenic zones and nodes. In accordance with continuum mechanics, the tensor nature of earthquake ground motion is preserved computing realistic signals using structural models obtained by tomographic inversion and earthquake source information readily available in literature. The way to this approach has been open by studies focused on continental Italy and Sicily, where the agreement between hazard maps obtained using seismogenic zones, informed by earthquake catalog data, and the maps obtained using only seismogenic nodes are very good.

scholarly journals SEISMIC HAZARD ASSESSMENT IN THE BROADER AEGEAN AREA USING TIME-INDEPENDENT SEISMICITY MODELS BASED ON SYNTHETIC EARTHQUAKE CATALOGS

2017 ◽  
Vol 50 (3) ◽  
pp. 1463
Author(s):  
D.A. Vamvakaris ◽  
C.B. Papazachos ◽  
Ch.A. Papaioannou ◽  
E.M. Scordilis ◽  
G.F. Karakaisis
Keyword(s):  
Seismic Hazard ◽  
Ground Motion ◽  
Hazard Assessment ◽  
Seismic Hazard Assessment ◽  
Aegean Area ◽  
Ground Motion Parameters ◽  
Earthquake Catalogs ◽  
Seismic Zones ◽  
Motion Parameters ◽  
Synthetic Catalogs

In order to evaluate the seismic hazard for the broader Aegean area, a modified timeindependent seismicity model is used. A Monte-Carlo procedure has been employed to create synthetic earthquake catalogs with specific characteristics regarding their time, space and magnitude distributions. Moreover, particular geometrical characteristics, such as subducting and oblique seismic zones are also taken into account in the synthetic catalogs generation. A significantly revised earthquake catalog, all available fault plane solutions and information on the seismotectonics of the broader Aegean area were considered in order to propose a new updated model of seismic zones for this area. Seismicity parameters for the new seismic zones were calculated and the corresponding synthetic earthquake catalogs were generated using the proposed procedure. The distribution of the expected values for ground motion parameters (e.g. PGA, PGV) was estimated using synthetic catalogs for several sites of interest, by performing computations directly on all earthquakes of each catalog. Computations were performed for a dense grid of sites and seismic hazard estimates were determined both directly from the peak ground motion distribution, as well as from fitted extreme values Gumbel distribution. Ground motion parameters were also calculated using classic seismic hazard assessment algorithms (EqRISK), in order to evaluate the compatibility of the proposed method with conventional approaches.

scholarly journals Monte Carlo Based Seismic Hazard Model for Southern Ghana

2018 ◽  
Vol 4 (7) ◽  
pp. 1510 ◽  
Author(s):  
Jack Banahene Osei ◽  
Mark Adom-Asamoah ◽  
Ahmed Ali Awadallah Ahmed ◽  
Eugene Boasiako Antwi
Keyword(s):  
Monte Carlo ◽  
Seismic Hazard ◽  
Ground Motion ◽  
Hazard Assessment ◽  
Peak Ground Acceleration ◽  
Seismic Hazard Assessment ◽  
Hazard Model ◽  
Ground Acceleration ◽  
Probability Of Exceedance ◽  
Southern Ghana

Seismic hazard assessment involves quantifying the likely ground motion intensities to be expected at a particular site or region. It is a crucial aspect of any seismic hazard mitigation program. The conventional probabilistic seismic hazard assessment is highly reliant on the past seismic activities in a particular region. However, for regions with lower rates of seismicity, where seismological data is scanty, it would seem desirable to use a stochastic modelling (Monte Carlo based) approach. This study presents a Monte Carlo simulation hazard model for Southern Ghana. Six sites are selected in order to determine their expected ground motion intensities (peak ground acceleration and spectral acceleration). Results revealed that Accra and Tema as the highly seismic cities in Southern Ghana, with Ho and Cape Coast having relatively lower seismicities. The expected peak ground acceleration corresponding to a 10% probability of exceedance in 50 years for the proposed seismic hazard model was as high as 0.06 g for the cities considered. However, at the rather extreme 2% probability of exceedance in 50 years, a PGA of 0.5 g can be anticipated. Evidently, the 2% in 50 years uniform hazard spectrum for the highly seismic cities recorded high spectral accelerations, at a natural vibrational period within the ranges of about 0.1-0.3 sec. This indicates that low-rise structures in these cities may be exposed to high seismic risk.

The 2018 national seismic hazard assessment of Australia: Quantifying hazard changes and model uncertainties

2020 ◽  
Vol 36 (1_suppl) ◽  
pp. 5-43 ◽  
Author(s):  
Trevor I Allen ◽  
Jonathan D Griffin ◽  
Mark Leonard ◽  
Dan J Clark ◽  
Hadi Ghasemi
Keyword(s):  
Seismic Hazard ◽  
Ground Motion ◽  
Hazard Assessment ◽  
Seismic Hazard Assessment ◽  
Earthquake Catalog ◽  
Motion Models ◽  
Ground Motion Attenuation ◽  
Attenuation Models ◽  
Instrumental Period ◽  
Ground Motion Models

Seismic hazard assessments in stable continental regions such as Australia face considerable challenges compared with active tectonic regions. Long earthquake recurrence intervals relative to historical records make forecasting the magnitude, rates, and locations of future earthquakes difficult. Similarly, there are few recordings of strong ground motions from moderate-to-large earthquakes to inform development and selection of appropriate ground-motion models (GMMs). Through thorough treatment of these epistemic uncertainties, combined with major improvements to the earthquake catalog, a 2018 National Seismic Hazard Assessment (NSHA18) of Australia has been undertaken. The resulting hazard levels at the 10% in 50-year probability of exceedance level are in general significantly lower than previous assessments, including hazard factors used in the Australian earthquake loading standard ( AS 1170.4–2007 (R2018)), demonstrating our evolving understanding of seismic hazard in Australia. The key reasons for the decrease in seismic hazard factors are adjustments to catalog magnitudes for earthquakes in the early instrumental period, and the use of modern ground-motion attenuation models. This article summarizes the development of the NSHA18 explores uncertainties associated with the hazard model, and identifies the dominant factors driving the resulting changes in hazard compared with previous assessments.

scholarly journals Seismic Hazard Assessment for the Tianshui Urban Area, Gansu Province, China

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Zhenming Wang ◽  
David T. Butler ◽  
Edward W. Woolery ◽  
Lanmin Wang
Keyword(s):  
Seismic Hazard ◽  
Ground Motion ◽  
Seismic Design ◽  
Hazard Analysis ◽  
Seismic Hazard Assessment ◽  
Gansu Province ◽  
Mitigation Measures ◽  
Peak Ground Velocity ◽  
Ground Acceleration ◽  
Acceleration Time Histories

A scenario seismic hazard analysis was performed for the city of Tianshui. The scenario hazard analysis utilized the best available geologic and seismological information as well as composite source model (i.e., ground motion simulation) to derive ground motion hazards in terms of acceleration time histories, peak values (e.g., peak ground acceleration and peak ground velocity), and response spectra. This study confirms that Tianshui is facing significant seismic hazard, and certain mitigation measures, such as better seismic design for buildings and other structures, should be developed and implemented. This study shows that PGA of 0.3 g (equivalent to Chinese intensity VIII) should be considered for seismic design of general building and PGA of 0.4 g (equivalent to Chinese intensity IX) for seismic design of critical facility in Tianshui.

scholarly journals The use of Monte Carlo simulations for seismic hazard assessment in the U.K.

2000 ◽  
Vol 43 (1) ◽  
Author(s):  
R. M. W. Musson
Keyword(s):  
Monte Carlo ◽  
Seismic Hazard ◽  
Hazard Assessment ◽  
Seismic Hazard Assessment ◽  
Probabilistic Seismic Hazard Assessment ◽  
Logic Tree ◽  
The United Kingdom ◽  
The Monte Carlo Method ◽  
Moderate Seismicity ◽  
Seismicity Model

The input required for a seismic hazard study using conventional Probabilistic Seismic Hazard assessment (PSHA) methods can also be used for probabilistic analysis of hazard using Monte Carlo simulation methods. This technique is very flexible, and seems to be under-represented in the literature. It is very easy to modify the form of the seismicity model used, for example, to introduce non-Poissonian behaviour, without extensive reprogramming. Uncertainty in input parameters can also be modelled very flexibly - for example, by the use of a standard deviation rather than by the discrete branches of a logic tree. In addition (and this advantage is perhaps not as trivial as it may sound) the simplicity of the method means that its principles can be grasped by the layman, which is useful when results have to be explained to people outside the seismological/engineering communities, such as planners and politicians. In this paper, some examples of the Monte Carlo method in action are shown in the context of a low to moderate seismicity area: the United Kingdom.

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