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1.
A probabilistic assessment of the seismic hazard in Turkey 总被引：1，自引：0，他引：1
2.
Shafiq Ur Rehman Muhammad Khalid Asif Ali Abd El-aziz Khairy Abd El-Aal 《Arabian Journal of Geosciences》2013,6(9):3481-3492
Gwadar City is located at the coastline of Pakistan. The city is currently in a phase of development, which is expected to become a future economic hub for Pakistan. This has led us to choose Gwadar for seismic hazard evaluation. Seismic hazard analysis for Gwadar is carried out using deterministic and probabilistic seismic hazard analysis techniques. The present study will help in sustainable development of a future large city and economic hub for Pakistan on ways of coping from a major threat of earthquake hazard. In deterministic seismic hazard analysis, line sources were identified close to Gwadar. Based on the analysis of maximum magnitude and closest distance (worse conditions), Makran subduction zone was identified out of all the line sources with earthquake potential of 8.2 at a distance of 30 km. This yielded a peak ground acceleration value of 0.38 g for Gwadar City. In second phase, probabilistic seismic hazard analysis technique with the area source modeling was adopted to acquire results at different return periods. For this purpose, seismic data were collected from the Pakistan Meteorological Department and International Seismological Center (2010) databases for development of a comprehensive data catalog. The a and b values were obtained using regression analysis for each source zone, and probabilistic analysis yielded the results of 0.34 g for a return period of 500 years. As per building codes of Pakistan, areas or cities with ground acceleration greater than 0.32 g are considered in seismic zone 4, and both deterministic and probabilistic hazard analysis place the city in seismic zone 4. These values correspond to rock site with shear wave velocity of 760 m/s. 相似文献
3.
A probabilistic procedure was applied to assess seismic hazard for the sites of five Greek cities (Athens, Heraklion, Patras, Thessaloniki and Volos) using peak ground acceleration as the hazard parameter. The methodology allows the use of either historical or instrumental data, or a combination of both. It has been developed specifically for the estimation of seismic hazard at a given site and does not require any specification of seismic sources or/and seismic zones. A new relation for the attenuation of peak ground acceleration was employed for the shallow seismicity in Greece. The computations involved the area- and site-specific parts. When assessing magnitude recurrence for the areas surrounding the five cities, the maximum magnitude, mmax, was estimated using a recently derived equation. The site-specific results were expressed as probabilities that a given peak ground acceleration value will be exceeded at least once during a time interval of 1, 50 and 100 years at the sites of the cities. They were based on the maximum peak ground acceleration values computed by assuming the occurrence of the strongest possible earthquake (of magnitude mmax) at a very short distance from the site and using the mean value obtained with the help of the attenuation law. This gave 0.24 g for Athens, 0.53 g for Heraklion (shallow) and 0.39 g Heraklion (intermediate-depth seismicity), 0.30 g for Patras, 0.35 g for Thessaloniki and 0.30 g for Volos. In addition, the probabilities of exceedance of the estimated maximum peak ground acceleration values were calculated for the sites. The standard deviation of the new Greek attenuation law demonstrates the uncertainty and large variation of predicted peak ground acceleration values. 相似文献
4.
Seismic Hazard for Selected Sites in Greece: A Bayesian Estimate of Seismic Peak Ground Acceleration 总被引：1，自引：1，他引：1
A procedure for estimating maximum values of seismic peak ground accelerationat the examined site and quantiles of its probabilistic distribution in a future timeinterval of a given length is considered. The input information for the method areseismic catalog and regression relation between peak seismic acceleration at a givenpoint and magnitude and distance from the site to epicenter (seismic attenuation law).The method is based on Bayesian approach, which simply accounts for influenceof uncertainties of seismic acceleration values. The main assumptions for the method are Poissonian character of seismic events flow and distribution law of Gutenberg-Richter's type. The method is applied to seismic hazard estimation in six selected sitesin Greece. 相似文献
5.
Probabilistic seismic hazard maps for the sultanate of Oman 总被引：2，自引：0，他引：2
I. El-Hussain A. Deif K. Al-Jabri N. Toksoz S. El-Hady S. Al-Hashmi K. Al-Toubi Y. Al-Shijbi M. Al-Saifi S. Kuleli 《Natural Hazards》2012,64(1):173-210
This study presents the results of the first probabilistic seismic hazard assessment (PSHA) in the framework of logic tree for Oman. The earthquake catalogue was homogenized, declustered, and used to define seismotectonic source model that characterizes the seismicity of Oman. Two seismic source models were used in the current study; the first consists of 26 seismic source zones, while the second is expressing the alternative view that seismicity is uniform along the entire Makran and Zagros zones. The recurrence parameters for all the seismogenic zones were determined using the doubly bounded exponential distribution except the zones of Makran, which were modelled using the characteristic distribution. Maximum earthquakes were determined and the horizontal ground accelerations in terms of geometric mean were calculated using ground-motion prediction relationships developed based upon seismic data obtained from active tectonic environments similar to those surrounding Oman. The alternative seismotectonic source models, maximum magnitude, and ground-motion prediction relationships were weighted and used to account for the epistemic uncertainty. Hazard maps at rock sites were produced for 5?% damped spectral acceleration (SA) values at 0.1, 0.2, 0.3, 1.0 and 2.0?s spectral periods as well as peak ground acceleration (PGA) for return periods of 475 and 2,475?years. The highest hazard is found in Khasab City with maximum SA at 0.2?s spectral period reaching 243 and 397?cm/s2 for return periods 475 and 2,475 years, respectively. The sensitivity analysis reveals that the choice of seismic source model and the ground-motion prediction equation influences the results most. 相似文献
6.
Intermediate-depth earthquakes in the Vrancea region occur in response to stress generation due to descending lithosphere
beneath the southeastern Carpathians. In this article, tectonic stress and seismicity are analyzed in the region on the basis
of a vast body of observations. We show a correlation between the location of intermediate-depth earthquakes and the predicted
localization of maximum shear stress in the lithosphere. A probabilistic seismic hazard assessment (PSHA) for the region is
presented in terms of various ground motion parameters on the utilization of Fourier amplitude spectra used in engineering
practice and risk assessment (peak ground acceleration, response spectra amplitude, and seismic intensity). We review the
PSHA carried out in the region, and present new PSHA results for the eastern and southern parts of Romania. Our seismic hazard
assessment is based on the information about the features of earthquake ground motion excitation, seismic wave propagation
(attenuation), and site effect in the region. Spectral models and characteristics of site-response on earthquake ground motions
are obtained from the regional ground motion data including several hundred records of small and large earthquakes. Results
of the probabilistic seismic hazard assessment are consistent with the features of observed earthquake effects in the southeastern
Carpathians and show that geological factors play an important part in the distribution of the earthquake ground motion parameters. 相似文献
7.
Mahmoud Hamlaoui K. Vanneste K. Baddari L. Louail B. Vleminckx A. Demdoum 《Arabian Journal of Geosciences》2017,10(11):238
This work involves updating the evaluation of seismic hazard in Northeast Algeria by a probabilistic approach. This reassessment attempts to resolve inconsistencies between seismic zoning in regional building codes and is further motivated by the need to refine the input data that are used to evaluate seismic hazard scenarios. We adopted a seismotectonic model that accounts for differences in interpretations of regional seismicity. We then performed a probabilistic assessment of regional seismic hazard in Northeast Algeria. Based on a homogeneous earthquake catalog and geological and seismotectonic data gathered in the first part of the study, a seismotectonic zoning map was created and seven risk areas were identified. For each area, peak ground acceleration hazard maps were produced. Details of the calculations are provided, including hazard curves at periods of 0.1, 0.2, 0.33, 0.5, 1.0, and 2.0 s and uniform hazard spectra at urban locations in the area, including Sétif, Constantine, Kherrata, Bejaia, and Jijel. 相似文献
8.
Attenuation relationships are commonly used for engineering studies to estimate the peak ground acceleration values. This
paper presents the role of attenuation relationship in defining the seismic hazard in an area. It is seen that the seismic
hazard in an area, which is calculated using attenuation relationships, is mostly controlled by the type of attenuation relationship
used in the study. The present work aims to study the effect of attenuation relationship on seismic hazard study. In the present
work, seismic hazard maps have been prepared in the seismically very active northeast Himalaya using the approach given by
Joshi and Patel (Tectonophysics 283:289–310, 1997). The attenuation relationships of Jain et al. (2000), Sharma (2000), Joyner and Boore (Bull Seism Soc Am 71:2011–2038, 1981) and Abrahamson and Litehiser (Bull Seism Soc Am 79:549–580, 1989) have been considered in the present study. Among all considered attenuation relationships, the Abrahamson and Litehiser
(Bull Seism Soc Am 79:549–580, 1989) attenuation relationship gives the least root mean square error between the recorded and calculated peak ground acceleration
values. Therefore, the same has been used to define attenuation characteristic of the region. The mean and standard deviation
of peak ground acceleration values at all the observation points due to above-mentioned attenuation relationships in the NE
Himalayas are calculated. The study shows that the Zone III covers an area of 81,000 km2 and Zone II of 96,000 km2 in the map prepared using the mean peak ground acceleration values, whereas the area of Zone IV increases by 40,000 km2 when the map is prepared by adding the standard deviation values in the mean peak ground acceleration values, and only Zone
II is left with 183,000 km2 when the standard deviation values are subtracted from the mean. This high standard deviation is due to the difference in
the peak ground acceleration values obtained from different events. This study shows that a rigorous test needs to be done
for selecting attenuation relationship for any hazard study in a given area. 相似文献
9.
Recent developments in the neotectonic framework of Turkey introduced new tectonic elements necessitating the reconstruction of Turkey's seismic hazard map. In this regard, 14 seismic source zones were delineated. Maximum earthquake magnitudes for each seismic zones were determined using the fault rupture length approximation. Regression coefficients of the earthquake magnitude–frequency relationships for the seismic zones were compiled mostly from earlier works. Along with these data, a strong ground motion attenuation relationship developed by Joyner and Boore [Joyner, W.B., Boore, D.M., 1988. Measurement, characterization, and prediction of strong ground motion. Earthquake Engineering and Soil Dynamics, 2. Recent Advances Ground Motion Evaluation, pp. 43–102.] was utilized to model the seismic hazard for Turkey using the probabilistic approach. For the modeling, the “earthquake location uncertainty” concept was employed. A grid of 5106 points with 0.2° intervals was constituted for the area encompassed by the 25–46°E longitudes and 35–43°N latitudes. For the return periods of 100 and 475 years, the peak horizontal ground acceleration (pga) in bedrock was computed for each grid point. Isoacceleration maps for the return periods of 100 and 475 years were constructed by contouring the pga values at each node. 相似文献
10.
Djillali Benouar 《Natural Hazards》1996,13(2):119-131
This paper presents the evaluation of seismic hazard at the site of Algiers (capital of Algeria). In order to implement earthquake-resistant design codes, it is usually necessary to know the maximum dynamic load which a particular structure might experience during its economic life, or alternatively, the most probable return period of a specified design load. The evaluation of the seismic hazard at the site, based on peak ground motion acceleration and using Cornell's method and Benouar's earthquake Maghreb catalogue, in terms of return period, probability of exceedance of PGA, design ground motion and a response spectrum, is carried out for the City of Algiers and its surroundings. The response spectrum for Algiers presented in this paper is the first one realized in Algeria using revised Algerian data. 相似文献
11.
A seismic hazard map of India and adjacent areas 总被引：1，自引：0，他引：1
We have produced a probabilistic seismic hazard map showing peak ground accelerations in rock for India and neighboring areas having a 10% probability of being exceeded in 50 years. Seismogenic zones were identified on the basis of historical seismicity, seismotectonics and geology of the region. Procedures for reducing the incompleteness of earthquake catalogs were followed before estimating recurrence parameters. An eastern United States acceleration attenuation relationship was employed after it was found that intensity attenuation for the Indian region and the eastern United States was similar. The largest probabilistic accelerations are obtained in the seismotectonic belts of Kirthar, Hindukush, Himalaya, Arakan-Yoma, and the Shillong massif where values of over 70% g have been calculated. 相似文献
12.
China is prone to highly frequent earthquakes due to specific geographical location, which could cause significant losses to society and economy. The task of seismic hazard analysis is to estimate the potential level of ground motion parameters that would be produced by future earthquakes. In this paper, a novel method based on fuzzy logic techniques and probabilistic approach is proposed for seismic hazard analysis (FPSHA). In FPSHA, we employ fuzzy sets for quantification of earthquake magnitude and source-to-site distance, and fuzzy inference rules for ground motion attenuation relationships. The membership functions for earthquake magnitude and source-to-site distance are provided based on expert judgments, and the construction of fuzzy rules for peak ground acceleration relationships is also based on expert judgment. This methodology enables to include aleatory and epistemic uncertainty in the process of seismic hazard analysis. The advantage of the proposed method is in its efficiency, reliability, practicability, and precision. A case study is investigated for seismic hazard analysis of Kunming city in Yunnan Province, People’s Republic of China. The results of the proposed fuzzy logic-based model are compared to other models, which confirms the accuracy in predicting the probability of exceeding a certain level of the peak ground acceleration. Further, the results can provide a sound basis for decision making of disaster reduction and prevention in Yunnan province. 相似文献
13.
香港地区地震风险评价和设防区划 总被引：3，自引：0，他引：3
香港地区隶属于中国板内地震区中的东南沿海块缘地震带。港-九块体为晚中生代至早第三纪以来以持续稳定上升为主的块体, 块体活动性明显地低于其周边相对下沉的中新生代盆地。为此, 赋予港-九块体为最大可信震级M=5.5级潜在震源区, 而其周边中新生代断陷盆地则为最大可信震级M6.0潜在震源。从大陆地震构造成因的环境、潜在震源可信震级范围M=5.0～7.5和近源地震动饱和等三个方面的可比性, 结合中国大陆地震震源破裂尺度和地震烈度影响场, 所建立的反映中国地震构造和震源破裂及地震烈度影响场特点的PGA和反应谱地震动衰减预测关系式可用于香港地区。以50%概率时的中值对中国强震记录的对比, 本研究所提供的经验期望预测关系式, 能包络实际的资料。因此, 用此地震动衰减预测模式对香港地区地震危险性进行评估, 将会得到相对保守地震动预测值。通过香港地区基岩地震动危险性分析和计算, 参照中国大陆地震设防标准, 进行了基岩设计参数确定和区划。以年概率P=0.02、P=0.002、P=0.0004三个概率标准, 对应的地震动重复周期大约分别约为50a, 500a, 2500a的基岩PGA和反应谱, 作为香港地区基岩上构筑物和建筑物可选的基 相似文献
14.
《Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards》2013,7(3-4):173-185
The most important seismic hazard parameters required to demarcate seismic zones are the peak horizontal acceleration (PHA) and spectral acceleration (SA). The two approaches for evaluation of seismic hazard are the probabilistic seismic hazard analysis and the deterministic seismic hazard analysis (DSHA). The present study evaluates the seismic hazard of the South Indian Peninsular region based on the DSHA methodology. In order to consider the epistemic uncertainties in a better manner, a logic tree approach was adopted in the evaluation of seismic hazard. Two types of seismic sources and three different attenuation relations were used in the analysis. The spatial variation of PHA (mean and 84th percentile values) and SA values for 1 Hz and 10 Hz at bedrock level (84th percentile values) for the entire study area were evaluated and the results are presented here. The surface level peak ground acceleration (PGA) values will be different from that of the bedrock level values due to the local site conditions. The PGA values at ground surface level were evaluated for four different National Earthquake Hazard Reduction Program site classes by considering the non-linear site response of different soil types. The response spectra for important cities in South India were also prepared using the deterministic approach and the results are presented in this paper. 相似文献
15.
16.
In the present study, the seismic hazard in northern Algeria is estimated using both physical strain energy release and Gumbel's extreme values approaches. For six of the most industrial and populated cities in Algeria, seismic hazard is assessed and examined in greater detail. Gumbel's extreme values approach has been used to estimate seismic hazard in terms of magnitude and P.G.A at each point of an equispaced grid all over the north of Algeria. An average attenuation relationship for PGA has been provided using known relations which have been established in regions with similar attenuation characteristics.The results are presented mainly in the form of graphs and contour maps of magnitudes (respectively PGA) with a 60% probability of not being exceeded in the next 100 and 200 years. Globally, they give main features of northern Algeria in terms of zoning (as well as in terms of magnitude and in terms of PGA). They corroborate the ones obtained through other works, especially in the basin areas (Mitidja, Cheliff, Soumam and Constantine Basin). 相似文献
17.
Probabilistic seismic hazard analysis for Sumatra, Indonesia and across the Southern Malaysian Peninsula 总被引：1，自引：0，他引：1
Mark D. Petersen James Dewey Stephan Hartzell Charles Mueller Stephan Harmsen ArthurD. Frankel Ken Rukstales 《Tectonophysics》2004,390(1-4):141-158
The ground motion hazard for Sumatra and the Malaysian peninsula is calculated in a probabilistic framework, using procedures developed for the US National Seismic Hazard Maps. We constructed regional earthquake source models and used standard published and modified attenuation equations to calculate peak ground acceleration at 2% and 10% probability of exceedance in 50 years for rock site conditions. We developed or modified earthquake catalogs and declustered these catalogs to include only independent earthquakes. The resulting catalogs were used to define four source zones that characterize earthquakes in four tectonic environments: subduction zone interface earthquakes, subduction zone deep intraslab earthquakes, strike-slip transform earthquakes, and intraplate earthquakes. The recurrence rates and sizes of historical earthquakes on known faults and across zones were also determined from this modified catalog. In addition to the source zones, our seismic source model considers two major faults that are known historically to generate large earthquakes: the Sumatran subduction zone and the Sumatran transform fault. Several published studies were used to describe earthquakes along these faults during historical and pre-historical time, as well as to identify segmentation models of faults. Peak horizontal ground accelerations were calculated using ground motion prediction relations that were developed from seismic data obtained from the crustal interplate environment, crustal intraplate environment, along the subduction zone interface, and from deep intraslab earthquakes. Most of these relations, however, have not been developed for large distances that are needed for calculating the hazard across the Malaysian peninsula, and none were developed for earthquake ground motions generated in an interplate tectonic environment that are propagated into an intraplate tectonic environment. For the interplate and intraplate crustal earthquakes, we have applied ground-motion prediction relations that are consistent with California (interplate) and India (intraplate) strong motion data that we collected for distances beyond 200 km. For the subduction zone equations, we recognized that the published relationships at large distances were not consistent with global earthquake data that we collected and modified the relations to be compatible with the global subduction zone ground motions. In this analysis, we have used alternative source and attenuation models and weighted them to account for our uncertainty in which model is most appropriate for Sumatra or for the Malaysian peninsula. The resulting peak horizontal ground accelerations for 2% probability of exceedance in 50 years range from over 100% g to about 10% g across Sumatra and generally less than 20% g across most of the Malaysian peninsula. The ground motions at 10% probability of exceedance in 50 years are typically about 60% of the ground motions derived for a hazard level at 2% probability of exceedance in 50 years. The largest contributors to hazard are from the Sumatran faults. 相似文献
18.
作为地震灾害评估的理论基础,地震动力学主要研究与地震活动有关的断裂机制、破裂过程、震源辐射和由此而引起的地震波的传播及地面运动规律。对地震力学、震源辐射和能量释放等经典理论问题进行了系统研究。在此基础上,应用最新的定量地震学研究方法,以逻辑树的形式综合地震、地质和大地测量资料,提供了不同构造环境和断裂机制条件下地震灾害评估的概率分析和确定性分析实例。用于震源分析的典型构造类型包括板内地壳震源层、地壳活动断层及其速率、板块俯冲界面和俯冲板片。由于输入模型中不确定因素的存在,如输入参数的随机性和科学分析方法本身的不确定性,对分析结果的不确定性需审慎对待。通常对不同的模型或参量,包括地面衰减模型,进行加权平均可较为合理地减小结果的偏差：概率分析和确定性分析方法的结合亦为可取之有效途径。 相似文献
19.
The performance-based liquefaction potential analysis was carried out in the present study to estimate the liquefaction return
period for Bangalore, India, through a probabilistic approach. In this approach, the entire range of peak ground acceleration
(PGA) and earthquake magnitudes was used in the evaluation of liquefaction return period. The seismic hazard analysis for
the study area was done using probabilistic approach to evaluate the peak horizontal acceleration at bed rock level. Based
on the results of the multichannel analysis of surface wave, it was found that the study area belonged to site class D. The
PGA values for the study area were evaluated for site class D by considering the local site effects. The soil resistance for
the study area was characterized using the standard penetration test (SPT) values obtained from 450 boreholes. These SPT data
along with the PGA values obtained from the probabilistic seismic hazard analysis were used to evaluate the liquefaction return
period for the study area. The contour plot showing the spatial variation of factor of safety against liquefaction and the
corrected SPT values required for preventing liquefaction for a return period of 475 years at depths of 3 and 6 m are presented
in this paper. The entire process of liquefaction potential evaluation, starting from collection of earthquake data, identifying
the seismic sources, evaluation of seismic hazard and the assessment of liquefaction return period were carried out, and the
entire analysis was done based on the probabilistic approach. 相似文献
20.
A first generation of probabilistic seismic hazard maps of the Italian country are presented. They are based on seismogenic zoning deriving from a kinematic model of the structural tectonic units and on an earthquake catalogue with the foreshock and aftershock events filtered out. The following ground motion parameters have been investigated and mapped using attenuation equations based on strong-motion recordings of Italian earthquakes: peak ground acceleration and velocity; Arias intensity; strong motion duration; and the pseudovelocity and pseudoacceleration spectral values at 14 fixed frequencies both for the vertical and the largest horizontal component. A Poissonian model of earthquake occurrence is assumed as a default and the hazard maps are presented in terms of ground motion values expected to be exceeded at a 10% probability level in 50 years (return period 475 years) according to the requirement of Eurocode 8 for the seismic classification of national territories, as well as in terms of exceedance probabilities of selected ground motion values. Finally, as a tentative study, the use of hybrid methods (implementing both seismogenic zones and structures), renewal processes (including earthquake forecasting) and the influence of site effects (as the basis for the planning of earthquake scenarios) were explored. 相似文献