Probabilistic Seismic Hazard Assessment of Sudan and Its Vicinity

2001 ◽  
Vol 17 (3) ◽  
pp. 399-415 ◽  
Author(s):  
Jamal A. Abdalla ◽  
Yahia E-A. Mohamedzein ◽  
A. Abdel Wahab
Keyword(s):  
Seismic Hazard ◽  
Hazard Assessment ◽  
Seismic Activity ◽  
Probabilistic Approach ◽  
Seismic Hazard Assessment ◽  
Seismic Source ◽  
Probabilistic Seismic Hazard Assessment ◽  
Seismic Zone ◽  
Ground Acceleration ◽  
Grid Points

This paper presents seismic hazard assessment and seismic zoning of Sudan and its vicinity based on probabilistic approach. The area studied lies between 22° E- 45° E and 0° - 24° N. Tectonics of Sudan and its vicinity is first reviewed. An updated NOAA catalogue, containing both historical and instrumental events and covering the period from 700 A.D. to 1993 is then used. Seismic source regions are modeled and relationships between earthquake magnitude and earthquake frequency are established. A modified attenuation relation is used. Seismic hazard assessment is then carried out for 60 km interval grid points. Seismic hazard maps of the studied area based on peak ground acceleration (PGA) for 10% probability of exceedance for time-spans of 50, 100, 200 and 250 years are presented. The results showed that the PGA ranges from 0.02g for low seismic activity regions to around 0.62g for high seismic activity regions. A seismic zone map is also shown for 475 years return period.

Probabilistic Seismic Hazard Assessment of the Kermanshah-Sanandaj Region of Western Iran

2007 ◽  
Vol 23 (1) ◽  
pp. 175-197 ◽  
Author(s):  
Elham Shabani ◽  
Noorbakhsh Mirzaei
Keyword(s):  
Seismic Hazard ◽  
Hazard Assessment ◽  
Eleventh Century ◽  
Probabilistic Approach ◽  
Seismic Hazard Assessment ◽  
Earthquake Hazard ◽  
Probabilistic Seismic Hazard Assessment ◽  
Return Periods ◽  
Ground Acceleration ◽  
Western Iran

Seismic hazard assessment and zoning of the Kermanshah-Sanandaj region in western Iran is conducted using probabilistic approach. Two maps have been prepared to indicate the earthquake hazard of the region in the form of iso-acceleration contour lines. They display a probabilistic estimate of peak ground acceleration (PGA) over bedrock for the return periods of 475 and 50 years. A uniform catalog of earthquakes containing historical and instrumental events covering the period from the eleventh century A.D. to 2003 is used. Twelve potential seismic sources are modeled as area sources in the region. Seismicity parameters are evaluated using the method in which magnitude uncertainty and incompleteness of earthquake data are considered. Seismic hazard assessment is carried out for a grid of 357 points with 0.1° intervals using the SEISRISKIII computer program for the study area encompassed by the 46–48° E longitudes and 34–36° N latitudes. This region includes the most active segments of the Zagros Main Recent Fault; among them, the Sahneh and Nahavand faults have a well-known history of intense seismic activity. PGA values for this region are estimated to be 0.35 g and 0.20 g for 475- and 50-years return periods, respectively.

scholarly journals Real-time probabilistic seismic hazard assessment based on seismicity anomaly

2020 ◽  
Vol 20 (3) ◽  
pp. 743-753
Author(s):  
Yu-Sheng Sun ◽  
Hsien-Chi Li ◽  
Ling-Yun Chang ◽  
Zheng-Kai Ye ◽  
Chien-Chih Chen
Keyword(s):  
Seismic Hazard ◽  
Real Time ◽  
Hazard Assessment ◽  
Seismic Hazard Assessment ◽  
Seismic Source ◽  
Seismic Intensity ◽  
Time Dependent ◽  
Occurrence Rate ◽  
Probabilistic Seismic Hazard Assessment ◽  
Probabilistic Seismic Hazard

Abstract. Real-time probabilistic seismic hazard assessment (PSHA) was developed in this study in consideration of its practicability for daily life and the rate of seismic activity with time. Real-time PSHA follows the traditional PSHA framework, but the statistic occurrence rate is substituted by time-dependent seismic source probability. Over the last decade, the pattern informatics (PI) method has been developed as a time-dependent probability model of seismic source. We employed this method as a function of time-dependent seismic source probability, and we selected two major earthquakes in Taiwan as examples to explore real-time PSHA. These are the Meinong earthquake (ML 6.6) of 5 February 2016 and the Hualien earthquake (ML 6.2) of 6 February 2018. The seismic intensity maps produced by the real-time PSHA method facilitated the forecast of the maximum expected seismic intensity for the following 90 d. Compared with real ground motion data from the P-alert network, our seismic intensity forecasting maps showed considerable effectiveness. This result indicated that real-time PSHA is practicable and provides useful information that could be employed in the prevention of earthquake disasters.

scholarly journals Planar Seismic Source Characterization Models Developed for Probabilistic Seismic Hazard Assessment of Istanbul

2017 ◽  
Author(s):  
Zeynep Gülerce ◽  
Kadir Buğra Soyman ◽  
Barış Güner ◽  
Nuretdin Kaymakci
Keyword(s):  
Seismic Hazard ◽  
Hazard Assessment ◽  
Seismic Hazard Assessment ◽  
Seismic Source ◽  
Probabilistic Seismic Hazard Assessment ◽  
Model Parameters ◽  
Probabilistic Seismic Hazard ◽  
Maximum Magnitude ◽  
Source Characterization ◽  
Seismicity Rates

Abstract. This contribution provides an updated planar seismic source characterization (SSC) model to be used in the probabilistic seismic hazard assessment (PSHA) for Istanbul. It defines planar rupture systems for the four main segments of North Anatolian Fault Zone (NAFZ) that are critical for the PSHA of Istanbul: segments covering the rupture zones of 1999 Kocaeli and Düzce earthquakes, Central Marmara, and Ganos/Saros segments. In each rupture system, the source geometry is defined in terms of fault length, fault width, fault plane attitude, and segmentation points. Activity rates and the magnitude recurrence models for each rupture system are established by considering geological and geodetic constraints and are tested based on the observed seismicity that associated with the rupture system. Uncertainty in the SSC model parameters (e.g. b-value, maximum magnitude, weights of the rupture scenarios) is considered in the logic tree. To acknowledge the effect of earthquakes that are not associated with the defined rupture systems on the hazard, a background zone is introduced and the seismicity rates in the background zone are calculated using smoothed-seismicity approach. The state-of-the-art SSC model presented here is the first fully-documented and ready-to-use fault-based SSC model developed for the PSHA of Istanbul.

scholarly journals Planar seismic source characterization models developed for probabilistic seismic hazard assessment of Istanbul

2017 ◽  
Vol 17 (12) ◽  
pp. 2365-2381 ◽  
Author(s):  
Zeynep Gülerce ◽  
Kadir Buğra Soyman ◽  
Barış Güner ◽  
Nuretdin Kaymakci
Keyword(s):  
Seismic Hazard ◽  
Hazard Assessment ◽  
Seismic Hazard Assessment ◽  
Seismic Source ◽  
Probabilistic Seismic Hazard Assessment ◽  
Model Parameters ◽  
Probabilistic Seismic Hazard ◽  
Maximum Magnitude ◽  
Source Characterization ◽  
Seismicity Rates

Abstract. This contribution provides an updated planar seismic source characterization (SSC) model to be used in the probabilistic seismic hazard assessment (PSHA) for Istanbul. It defines planar rupture systems for the four main segments of the North Anatolian fault zone (NAFZ) that are critical for the PSHA of Istanbul: segments covering the rupture zones of the 1999 Kocaeli and Düzce earthquakes, central Marmara, and Ganos/Saros segments. In each rupture system, the source geometry is defined in terms of fault length, fault width, fault plane attitude, and segmentation points. Activity rates and the magnitude recurrence models for each rupture system are established by considering geological and geodetic constraints and are tested based on the observed seismicity that is associated with the rupture system. Uncertainty in the SSC model parameters (e.g., b value, maximum magnitude, slip rate, weights of the rupture scenarios) is considered, whereas the uncertainty in the fault geometry is not included in the logic tree. To acknowledge the effect of earthquakes that are not associated with the defined rupture systems on the hazard, a background zone is introduced and the seismicity rates in the background zone are calculated using smoothed-seismicity approach. The state-of-the-art SSC model presented here is the first fully documented and ready-to-use fault-based SSC model developed for the PSHA of Istanbul.

scholarly journals Probabilistic seismic hazard assessment in Greece – Part 1: Engineering ground motion parameters

2010 ◽  
Vol 10 (1) ◽  
pp. 25-39 ◽  
Author(s):  
G-A. Tselentis ◽  
L. Danciu
Keyword(s):  
Seismic Hazard ◽  
Hazard Assessment ◽  
Peak Ground Acceleration ◽  
Seismic Hazard Assessment ◽  
Peak Ground Velocity ◽  
Probabilistic Seismic Hazard Assessment ◽  
Probabilistic Seismic Hazard ◽  
Arias Intensity ◽  
Ground Acceleration ◽  
Cumulative Absolute Velocity

Abstract. Seismic hazard assessment represents a basic tool for rational planning and designing in seismic prone areas. In the present study, a probabilistic seismic hazard assessment in terms of peak ground acceleration, peak ground velocity, Arias intensity and cumulative absolute velocity computed with a 0.05 g acceleration threshold, has been carried out for Greece. The output of the hazard computation produced probabilistic hazard maps for all the above parameters estimated for a fixed return period of 475 years. From these maps the estimated values are reported for 52 Greek municipalities. Additionally, we have obtained a set of probabilistic maps of engineering significance: a probabilistic macroseismic intensity map, depicting the Modified Mercalli Intensity scale obtained from the estimated peak ground velocity and a probabilistic seismic-landslide map based on a simplified conversion of the estimated Arias intensity and peak ground acceleration into Newmark's displacement.

scholarly journals Probabilistic seismic hazard assessment of Bishkek, Kyrgyzstan, considering empirically estimated site effects

2015 ◽  
Vol 58 (1) ◽  
Author(s):  
Shahid Ullah ◽  
Dino Bindi ◽  
Marco Pilz ◽  
Stefano Parolai
Keyword(s):  
Seismic Hazard ◽  
Ground Motion ◽  
Hazard Assessment ◽  
Site Effects ◽  
Response Spectrum ◽  
Seismic Hazard Assessment ◽  
Geological Structure ◽  
Probabilistic Seismic Hazard Assessment ◽  
Site Classification ◽  
Ground Acceleration

<p>It is well known that variability in the surface geology potentially leads to the modification of earthquake-induced ground motion over short distances. Although this effect is of major importance when seismic hazard is assessed at the urban level, it is very often not appropriately accounted for. In this paper, we present a first attempt at taking into account the influence of the shallow geological structure on the seismic hazard assessment for Bishkek, Kyrgyzstan, using a proxy (Vs30) that has been estimated from in situ seismic noise array analyses, and considering response spectral ratios calculated by analyzing a series of earthquake recordings of a temporary seismic network. To highlight the spatial variability of the observed ground motion, the obtained results are compared with those estimated assuming a homogeneous Vs30 value over the whole urban area. The seismic hazard is evaluated in terms of peak ground acceleration (PGA) and spectral acceleration (SA) at different periods (frequencies). The presented results consider the values obtained for a 10% probability of exceedance in 50 years. The largest SA estimated considering a rock site classification of the area (0.43 g) is observed for a period of 0.1 s (10 Hz), while the maximum PGA reaches 0.21 g. When site effects are included through the Vs30 proxy in the seismic hazard calculation, the largest SA, 0.67 g, is obtained for a period of 0.3 s (about 3.3 Hz). In terms of PGA, in this case the largest estimated value reaches 0.31 g in the northern part of the town. When the variability of ground motion is accounted for through response spectrum ratios, the largest SA reaches a value as high as 1.39 g at a period of 0.5 s. In general, considering site effects in the seismic hazard assessment of Bishkek leads to an increase of seismic hazard in the north of the city, which is thus identified as the most hazardous part within the study area and which is more far away from the faults.</p>

scholarly journals Probabilistic Seismic Hazard Assessment (PSHA) for Lesvos Island Using the Logic Tree Approach

2019 ◽  
Vol 55 (1) ◽  
pp. 109 ◽  
Author(s):  
Nikolaos Vavlas ◽  
Anastasia Kiratzi ◽  
Basil Margaris ◽  
George Karakaisis
Keyword(s):  
Seismic Hazard ◽  
Hazard Assessment ◽  
High Efficiency ◽  
Seismic Hazard Assessment ◽  
Aegean Sea ◽  
Peak Ground Velocity ◽  
Probabilistic Seismic Hazard Assessment ◽  
Probabilistic Seismic Hazard ◽  
Building Stock ◽  
Ground Acceleration

We carry out a probabilistic seismic hazard assessment (PSHA) for Lesvos Island, in the northeastern Aegean Sea. Being the most populated island in the northern Aegean Sea and hosting the capital of the prefecture, its seismic potential has significant social-economic meaning. For the seismic hazard estimation, the newest version of the R-CRISIS module, which has high efficiency and flexibility in model selection, is used. We incorporate into the calculations eight (8) ground motion prediction equations (GMPEs). The measures used are peak ground acceleration, (PGA), peak ground velocity, (PGV), and spectral acceleration, (SA), at T=0.2 sec representative of the building stock. We calculate hazard curves for selected sites on the island, sampling the southern and northern parts: Mytilene, the capital, the village of Vrisa, Mithymna and Sigri. Hazard maps are also presented in terms of all three intensity measures, for a mean return period of 475 years (or 10% probability of exceedance in 50 years), assuming a Poisson process. Our results are comparable to the predictions of on-going EU hazard models, but higher than the provisions of the Greek Seismic Code. Finally, we perform disaggregation of hazard to depict the relative contribution of different earthquake sources and magnitudes to the results.

Probabilistic Seismic Hazard Assessment in Countries With Low Seismicity

2014 ◽  
Author(s):  
Katerina Demjancukova ◽  
Dana Prochazkova
Keyword(s):  
Seismic Hazard ◽  
Ground Motion ◽  
Hazard Assessment ◽  
Seismic Activity ◽  
Power Plants ◽  
Seismic Hazard Assessment ◽  
Seismic Hazards ◽  
Probabilistic Seismic Hazard Assessment ◽  
Geological Unit ◽  
Fault Displacement

The region of the Czech Republic is mostly composed of the Bohemian Massif which is considered as a geological unit with low seismic activity. Nevertheless, all critical objects as the nuclear power plants, big dams etc. are built as aseismic structures. The nuclear installations have to satisfy the IAEA safety standards and requirements. One of important phenomena that have to be involved in the PSHA process is the diffuse seismicity. In 2010 International Atomic Energy Agency issued a specific safety guide SSG-9 Seismic Hazards in Site Evaluation for Nuclear Installations. The key chapters are focused on general recommendations, necessary information and investigations (database), construction of a regional seismotectonic model, evaluation of the ground motion hazard, probabilistic seismic hazards analysis (PSHA), deterministic seismic hazards analysis, potential for fault displacement at the site, design basis ground motion, fault displacement and other hazards, evaluation of seismic hazards for nuclear installations other than NPPs. In the paper a numerical example of seismic hazard assessment will be presented with emphasis on problems and particularities related to PSHA in countries with low seismic activity.

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