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 Neo-deterministic seismic hazard maps of Kosovo

2021 ◽  
Author(s):  
Enrico Brandmayr ◽  
Vaccari Franco ◽  
Romanelli Fabio ◽  
Vlahovic Gordana ◽  
Panza Giuliano Francesco
Keyword(s):  
Seismic Hazard ◽  
Ground Motion ◽  
Seismic Hazard Assessment ◽  
Active Regions ◽  
Earthquake Hazard ◽  
Earthquake Ground Motion ◽  
Hazard Maps ◽  
Source Information ◽  
Deterministic Seismic Hazard ◽  
Traditional Construction

Kosovo is one of the most seismically active regions in Europe, lying within the Alpine-Mediterranean tectonic belt. Historical records for the region show several catastrophic earthquakes with epicentral intensity IX (MCS). However, due to Kosovo’s high population density, high prevalence of traditional construction, and insufficient enforcement of building codes, Kosovo is vulnerable to earthquake damage. In this study, we present earthquake hazard maps for bedrock conditions in Kosovo based on the well-known Neo-deterministic Seismic Hazard Assessment (NDSHA) method. NDSHA relies upon the fundamental physics of wave generation and propagation in complex geologic structures to generate realistic time series, used as input for the computation of several ground motion parameters, integrating the available knowledge of seismic history, seismogenic zones and morphostructural nodes. In accordance with continuum mechanics, the tensor nature of earthquake ground motion is preserved, producing realistic signals using structural models obtained by tomographic inversion and earthquake source information readily available in literature. Our maps are generally consistent with the observed intensity IX (MCS) and suggest that, in some instances, intensity X could be reached.

Seismic hazard maps based on Neo-deterministic Seismic Hazard Assessment for China Seismic Experimental Site and adjacent areas

2021 ◽  
pp. 106208
Author(s):  
Yan Zhang ◽  
Fabio Romanelli ◽  
Franco Vaccari ◽  
Antonella Peresan ◽  
Changsheng Jiang ◽  
...  
Keyword(s):  
Seismic Hazard ◽  
Hazard Assessment ◽  
Seismic Hazard Assessment ◽  
Hazard Maps ◽  
Experimental Site ◽  
Seismic Hazard Maps ◽  
Deterministic Seismic Hazard

scholarly journals Probabilistic seismic hazard assessment for Hanoi city

2019 ◽  
Vol 41 (4) ◽  
pp. 321-338
Author(s):  
Pham The Truyen ◽  
Nguyen Hong Phuong
Keyword(s):  
Seismic Hazard ◽  
Hazard Assessment ◽  
Seismic Hazard Assessment ◽  
Probabilistic Seismic Hazard Assessment ◽  
Probabilistic Seismic Hazard ◽  
Earthquake Catalog ◽  
Return Periods ◽  
Hazard Maps ◽  
Seismic Hazard Maps ◽  
S Period

In this study, the methodology of probabilistic seismic hazard assessment proposed by Cornell and Esteva in 1968 was applied for Hanoi city, using an earthquake catalog updated until 2018 and a comprehensive seismotectonic model of the territory of Vietnam and adjacent sea areas. Statistical methods were applied for declustering the earthquake catalog, then the maximum likelihood method was used to estimate the parameters of the Gutenberg–Richter Law and the maximum magnitude for each seismic source zone. Two GMPEs proposed by Campbell & Bozorgnia (2008) and Akkar et al., (2014) were selected for use in hazard analysis. Results of PSHA for Hanoi city are presented in the form of probabilistic seismic hazard maps, depicting peak horizontal ground acceleration (PGA) as well as 5-hertz (0.2 sec period) and 1-hertz (1.0 sec. period) spectral accelerations (SA) with 5-percent damping on a uniform firm rock site condition, with 10%, 5%, 2% and 0,5% probability of exceedance in 50 years, corresponding to return times of 475; 975; 2,475 and 9,975 years, respectively. The results of PSHA show that, for the whole territory of Hanoi city, for all four return periods, the predicted PGA values correspond to the intensity of VII to IX degrees according to the MSK-64 scale. As for the SA maps, for all four return periods, the predicted SA values at 1.0 s period correspond to the intensity of VI to VII, while the predicted SA values at 0.2 s period correspond to the intensity of VIII to X according to the MSK-64 scale. This is the last updated version of the probabilistic seismic hazard maps of Hanoi city. The 2019 probabilistic seismic hazard maps of Hanoi city display earthquake ground motions for various probability levels and can be applied in seismic provisions of building codes, insurance rate structures, risk assessments, and other public policy.

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 Selection of the appropriate methodology for the deterministic seismic hazard assessment on the territory of the Republic of Serbia

2006 ◽  
Vol 4 (1) ◽  
pp. 41-50
Author(s):  
Borko Bulajic ◽  
Miodrag Manic
Keyword(s):  
Seismic Hazard ◽  
Ground Motion ◽  
Strong Earthquake ◽  
Hazard Analysis ◽  
Seismic Hazard Assessment ◽  
Earthquake Ground Motion ◽  
Time Histories ◽  
Deterministic Seismic Hazard ◽  
The Republic ◽  
Probabilistic Nature

This paper presents a discussion regarding the most common approaches to the deterministic seismic hazard analysis, as well as their relation with the probabilistic hazard analysis. Different methodologies for estimation of the strong earthquake ground motion at a site of interest on the territory of the Republic of Serbia are also discussed. When generation of the synthetic ground motion time histories on the territory of the Republic of Serbia is concerned, a method developed by Trifunac and his associates is suggested having in mind that this approach uses only those input parameters that can be easily and accurately defined while at the same time being able to model all properties of strong earthquake ground motion that are presently known as well as to consider the probabilistic nature of earthquake occurrence.

Special Issue on Strong Ground Motion Prediction and Seismic Hazard Assessment

2013 ◽  
Vol 8 (5) ◽  
pp. 847-847
Author(s):  
Hiroyuki Fujiwara
Keyword(s):  
Seismic Hazard ◽  
Ground Motion ◽  
Hazard Assessment ◽  
Strong Ground Motion ◽  
Seismic Hazard Assessment ◽  
Hazard Maps ◽  
Special Issue ◽  
Strong Ground Motion Prediction ◽  
Large Earthquakes ◽  
Strong Ground

We have been conducting seismic hazard assessment for Japan under the guidance of the Headquarters for Earthquake Research Promotion of Japan since the 1995 Hyogo-ken Nanbu Earthquake, and have made National Seismic Hazard Maps for Japan for use in estimating strong ground motion caused by future earthquakes. This special issue reviews the results of these efforts. Such work includes the development of seismic hazard assessment methodology for Japan, highly accurate prediction techniques for strong seismic ground motion and modeling underground structures for evaluating strong ground motion. Related research on utilization initiatives and risk assessment based on hazard information has also been conducted. An open Web system – the Japan Seismic Hazard Information Station (J-SHIS) – has even been developed to provide information interactively. The 2011 Mw9.0 Great East Japan Earthquake was the largest such event recorded in the history of Japan. This megathrust earthquake was not considered in National Seismic Hazard Maps for Japan. But efforts toward revising seismic hazard assessment in Japan are progressing based on lessons learned from this earthquake. Hazard assessment is currently being reviewed in relation to the large earthquakes anticipated to occur in the near future based in the Sagami Trough and the Nankai Trough in the waters of offshore Japan. This assessment, which considers earthquakes larger than those assumed to have occurred in the past, is being reviewed as of this writing. In light of these pressing circumstances, studies are now being implemented to evaluate the long-period ground motion accompanying these large earthquakes. The knowledge that has been cultivated in Japan in terms of seismic hazard assessment has reached a high level, and it is important to expand such knowledge both internationally and domestically. This is just one of the reasons that efforts here in Japan are being made to help improve the level of seismic hazard assessment in the Asian region and throughout the entire world. It is expected that this special issue will help contribute to the further development of strong ground motion prediction and seismic hazard assessment now and in the future. Finally, I extend our sincere thanks to all of the contributors and reviewers involved with these articles.

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.

scholarly journals Seismogenic nodes as a viable alternative to seismogenic zones and observed seismicity for the definition of seismic hazard at regional scale

2019 ◽  
Vol 41 (4) ◽  
pp. 289-304 ◽  
Author(s):  
Paolo Rugarli ◽  
Franco Vaccari ◽  
Giuliano Panza
Keyword(s):  
Seismic Hazard ◽  
Safety Factor ◽  
Seismic Moment ◽  
Regional Scale ◽  
Seismic Hazard Assessment ◽  
Hazard Maps ◽  
Earthquake Catalogues ◽  
Definition Of ◽  
Partial Factor ◽  
Seismogenic Nodes

A fixed increment of magnitude is equivalent to multiply the seismic moment by a factor γEM related to the partial factor γq acting on the seismic moment representing the fault. A comparison is made between the hazard maps obtained with the Neo-Deterministic Seismic Hazard Assessment (NDSHA), using two different approaches: one based on the events magnitude, listed in parametric earthquake catalogues compiled for the study areas, with sources located within the seismogenic zones; the other uses the seismogenic nodes identified by means of pattern recognition techniques applied to morphostructural zonation (MSZ), and increases the reference magnitude by a constant amount tuned by the safety factor γEM.Using γEM=2.0, in most of the territory the two approaches produce totally independent, comparable hazard maps, based on the quite long Italian catalogue. This represents a validation of the seismogenic nodes method and a tuning of the safety factor γEM at about 2.

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