scholarly journals RE-EVALUATION OF SEISMIC HAZARD IN TASIKMALAYA CITY USING PROBABILISTIC APPROACH

2019 ◽  
Vol 17 (63) ◽  
Author(s):  
Bambang Sunardi
Keyword(s):  
Seismic Hazard ◽  
Probabilistic Approach

scholarly journals Comparison between seismic and domestic risk in moderate seismic hazard prone region: the Grenoble City (France) test site

2012 ◽  
Vol 12 (2) ◽  
pp. 511-526 ◽  
Author(s):  
F. Dunand ◽  
P. Gueguen
Keyword(s):  
Seismic Hazard ◽  
Seismic Risk ◽  
Probabilistic Approach ◽  
Test Site ◽  
Local Policy ◽  
Seismic Risk Analysis ◽  
Public Authorities ◽  
Policy Makers ◽  
Risk Acceptability ◽  
Social Importance

Abstract. France has a moderate level of seismic activity, characterized by diffuse seismicity, sometimes experiencing earthquakes of a magnitude of more than 5 in the most active zones. In this seismicity context, Grenoble is a city of major economic and social importance. However, earthquakes being rare, public authorities and the decision makers are only vaguely committed to reducing seismic risk: return periods are long and local policy makers do not have much information available. Over the past 25 yr, a large number of studies have been conducted to improve our knowledge of seismic hazard in this region. One of the decision-making concerns of Grenoble's public authorities, as managers of a large number of public buildings, is to know not only the seismic-prone regions, the variability of seismic hazard due to site effects and the city's overall vulnerability, but also the level of seismic risk and exposure for the entire city, also compared to other natural or/and domestic hazards. Our seismic risk analysis uses a probabilistic approach for regional and local hazards and the vulnerability assessment of buildings. Its applicability to Grenoble offers the advantage of being based on knowledge acquired by previous projects conducted over the years. This paper aims to compare the level of seismic risk with that of other risks and to introduce the notion of risk acceptability in order to offer guidance in the management of seismic risk. This notion of acceptability, which is now part of seismic risk consideration for existing buildings in Switzerland, is relevant in moderately seismic-prone countries like France.

scholarly journals Updating seismic hazard models for Kuwait

2021 ◽  
Author(s):  
Abd el-aziz Khairy Abd el-aal ◽  
Shaimaa Ismail Mostafa ◽  
Abdullah Al-Enezi ◽  
Farah Al-Jeri ◽  
Ammar Al-Sayegh
Keyword(s):  
Seismic Hazard ◽  
Seismic Risk ◽  
Epistemic Uncertainty ◽  
Probabilistic Approach ◽  
Tall Buildings ◽  
Seismic Source ◽  
Hazard Maps ◽  
Seismicity Pattern ◽  
Uniform Hazard Spectrum ◽  
The State Of Kuwait

Abstract The valuable results from this research are the first and essential step for assessing seismic risk in Kuwait. The increase in the urban development and construction of tall buildings and skyscrapers in Kuwait necessitated an estimate of the seismic risk for creating a unified seismic code for Kuwait. This research comes to make the necessarily step by assessing the seismic hazard and deaggregation in the State of Kuwait. For this purpose, the historical and instrumental seismic catalogs of Kuwait and the active Zagros Seismic Belt were primarily compiled, unifying the magnitudes, removing unnecessary earthquakes (seismicity declustering) and considering the completeness of the catalogs. Multi-seismotectonic models for Kuwait region incorporate earthquake focal mechanisms, seismicity pattern, and structural geological situation have been created to reduce epistemic uncertainty. The recurrence parameters as well as the maximum expected earthquake from each seismic source were fundamentally estimated. Appropriate ground motion attenuation relation within a logic tree formulation was mainly used in creating hazard maps. A state-of-the-art probabilistic approach is used herein to produce hazard maps at return periods of 75, 475, 975 and 2475 years (equivalent to 50%, 10%, 5% and 2%, respectively, probability of exceedance in 50 years) at periods of PGA, 0.1, 1 and 4 seconds. The computations of hazard maps were constructed using spacing grid of 0.2° × 0.2° all over the Kuwait area. Uniform hazard spectrum and deaggregation charts have been adopted for all six governorates of Kuwait. These results with vulnerability index are the main components for estimating the seismic risk of Kuwait.

scholarly journals Hazard-Consistent Earthquake Scenario Selection for Seismic Slope Stability Assessment

2020 ◽  
Vol 12 (12) ◽  
pp. 4977
Author(s):  
Alexey Konovalov ◽  
Yuriy Gensiorovskiy ◽  
Andrey Stepnov
Keyword(s):  
Slope Stability ◽  
Seismic Hazard ◽  
Ground Motion ◽  
Slope Failure ◽  
Probabilistic Approach ◽  
Seismic Loading ◽  
Time Interval ◽  
Total Probability ◽  
Ground Shaking ◽  
Earthquake Scenario

Design ground shaking intensity, based on probabilistic seismic hazard analysis (PSHA) maps, is most commonly used as a triggering condition to analyze slope stability under seismic loading. Uncertainties that are associated with expected ground motion levels are often ignored. This study considers an improved, fully probabilistic approach for earthquake scenario selection. The given method suggests the determination of the occurrence probability of various ground motion levels and the probability of landsliding for these ground motion parameters, giving the total probability of slope failure under seismic loading in a certain time interval. The occurrence hazard deaggregation technique is proposed for the selection of the ground shaking level, as well as the magnitude and source-to-site distance of a design earthquake, as these factors most probably trigger slope failure within the time interval of interest. An example application of the approach is provided for a slope near the highway in the south of Sakhalin Island (Russia). The total probability of earthquake-induced slope failure in the next 50 years was computed to be in the order of 16%. The scenario peak ground acceleration value estimated from the disaggregated earthquake-induced landslide hazard is 0.15g, while the 475-year seismic hazard curve predicts 0.3g. The case study highlights the significant difference between ground shaking scenario levels in terms of the 475-year seismic hazard map and the considered fully probabilistic approach.

scholarly journals A probabilistic approach for earthquake hazard assessment of the Province of Eskişehir, Turkey

2007 ◽  
Vol 7 (5) ◽  
pp. 607-614 ◽  
Author(s):  
A. Orhan ◽  
E. Seyrek ◽  
H. Tosun
Keyword(s):  
Seismic Hazard ◽  
Probabilistic Approach ◽  
Earthquake Hazard ◽  
Hazard Maps ◽  
City Center ◽  
Ground Acceleration ◽  
Western Turkey ◽  
Seismic Hazard Maps ◽  
Earthquake Hazard Assessment ◽  
The City

Abstract. The city of Eskişehir in inner-western Turkey has experienced a destructive earthquake with Ms=6.4 in 1956 in addition to many events with magnitudes greater than 5. It is located in a wide basin having young sedimentary units and thick alluvium soils which also include liquefiable sand materials. There is also an active fault passing beneath the city center and the groundwater level is very close to the ground surface. Approximately 600 thousand people are living in the province of Eskişehir. Therefore, the city and its vicinity have a high risk, when earthquake hazard is considered. This paper summarizes the probabilistic seismic hazard analysis (PSHA) which was performed for the province of Eskişehir and introduces seismic hazard maps produced by considering earthquakes with magnitude Ms≥4.0 occurred during the last 100-years and a seismic model composed of four seismic sources. The results of PSHA show that the average peak ground acceleration (PGA) for the city center is 0.40 g for 10 percent probability of exceedance in 50 years, for rock site. The seismic hazard maps were obtained by means of a program of Geographic Information System.

scholarly journals Seismicity and Seismotectonics of the Western Lake Ontario Region

2007 ◽  
Vol 47 (3) ◽  
pp. 353-362 ◽  
Author(s):  
Arsalan A. Mohajer
Keyword(s):  
Seismic Hazard ◽  
Probabilistic Approach ◽  
Lake Ontario ◽  
Historical Earthquakes ◽  
Depth Range ◽  
Seismic Zone ◽  
Considerable Uncertainty ◽  
Local Earthquakes ◽  
Western Lake ◽  
Hazard Assessments

ABSTRACTThe western Lake Ontario region, a traditionally perceived area of low seismic risk, is densely populated and is home to, among other critical facilities, the nuclear reactors of Pickering and Darlington. These and other characteristics of the region call for improved estimates of seismic hazard. Due to a lack of understanding of the causative geological sources and recurrence characteristics of the reported seismic activity, there is considerable uncertainty regarding estimated ground motion parameters, a fundamental component of seismic hazard assessments. To attempt to improve the definition of the seismic source zones and, consequently, seismic hazard assessments, the hypocentres of about 30 local earthquakes were recomputed. A new data compilation, based on the revised locations or those with the least travel-time residuals, shows that local microearthquakes (ML"3.5) generally occur along, or at the intersection of, prominent aeromagnetic or gravity anomalies. A notable seismicity trend extends in a northeast-southwest direction between Toronto and Hamilton, and is bounded by magnetic lineaments. A major geological structure, the Central Metasedimentary Belt Boundary Zone (CMBBZ), coincides with a strong aeromagnetic anomaly which extends to the northeast into the Western Québec Seismic Zone. This magnetic lineament also extends to the south, across Lake Ontario, to join the Akron (Ohio) magnetic boundary that was associated with several historical earthquakes and with a mb=4.9 earthquake in 1986. Most of the seismic events recorded instrumentally in the 20th century have occurred within a depth range of 5 to 20 km. This observation supports the correlation of local earthquakes with deep geophysical and geological features, suggesting contemporary reactivation of basement structures. This may imply that a more conservative deterministic hazard estimate is needed to verify the probabilistic approach currently used to assess seismic hazard in southern Ontario.

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