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1.
Seismic hazard and site-specific ground motion for typical ports of Gujarat   总被引：3，自引：3，他引：0  
Economic importance of major ports is well known, and if ports are located in seismically active regions, then site-specific seismic hazard studies are essential to mitigate the seismic risk of the ports. Seismic design of port sites and related structures can be accomplished in three steps that include assessment of regional seismicity, geotechnical hazards, and soil structure interaction analysis. In the present study, site-specific probabilistic seismic hazard analysis is performed to identify the seismic hazard associated with four typical port sites of Gujarat state (bounded by 20°–25.5°N and 68°–75°E) of India viz. Kandla, Mundra, Hazira, and Dahej ports. The primary aim of the study is to develop consistent seismic ground motion for the structures within the four port sites for different three levels of ground shaking, i.e., operating level earthquake (72 years return period), contingency level earthquake (CLE) (475 year return period), and maximum considered earthquake (2,475 year return period). The geotechnical characterization for each port site is carried out using available geotechnical data. Shear wave velocities of the soil profile are estimated from SPT blow counts using various empirical formulae. Seismicity of the Gujarat region is modeled through delineating the 40 fault sources based on the seismotectonic setting. The Gujarat state is divided into three regions, i.e., Kachchh, Saurashtra, and Mainland Gujarat, and regional recurrence relations are assigned in the form of Gutenberg-Richter parameters in order to calculate seismic hazard associated with each port site. The horizontal component of ground acceleration for three levels of ground shaking is estimated by using different ground motion attenuation relations (GMAR) including one country-specific GMAR for Peninsular India. Uncertainty in seismic hazard computations is handled by using logic tree approach to develop uniform hazard spectra for 5% damping which are consistent with the specified three levels of ground shaking. Using recorded acceleration time history of Bhuj 2001 earthquake as the input time motion, synthetic time histories are generated to match the developed designed response spectra to study site-specific responses of port sites during different levels of ground shaking. It is observed that the Mundra and Kandla port sites are most vulnerable sites for seismic hazard as estimated CLE ground motion is in order of 0.79 and 0.48 g for Mundra and Kandla port sites, respectively. Hazira and Dahej port sites have comparatively less hazard with estimated CLE ground motion of 0.17 and 0.11 g, respectively. The ground amplification factor is observed at all sites which ranges from 1.3 to 2.0 for the frequency range of 1.0–2.7 Hz. The obtained spectral accelerations for the three levels of ground motions and obtained transfer functions for each port sites are compared with provisions made in Indian seismic code IS:1893-Part 1 (2002). The outcome of present study is recommended for further performance-based design to evaluate the seismic response of the port structures with respect to various performance levels.  相似文献   

2.
In view of the major advancement made in understanding the seismicity and seismotectonics of the Indian region in recent times, an updated probabilistic seismic hazard map of India covering 6–38°N and 68–98°E is prepared. This paper presents the results of probabilistic seismic hazard analysis of India done using regional seismic source zones and four well recognized attenuation relations considering varied tectonic provinces in the region. The study area was divided into small grids of size 0.1° × 0.1°. Peak Horizontal Acceleration (PHA) and spectral accelerations for periods 0.1 s and 1 s have been estimated and contour maps showing the spatial variation of the same are presented in the paper. The present study shows that the seismic hazard is moderate in peninsular shield, but the hazard in most parts of North and Northeast India is high.  相似文献   

3.
Seismic hazard assessment is the key tool for rational planning, safety and design of infrastructures in seismically vulnerable regions. Gujarat is the only state in peninsular India with the maximum seismic hazard of large shallow earthquakes originating from intra-plate seismicity. Probabilistic seismic hazard assessment (PSHA) of Gujarat is carried out in this paper. Three seismogenic sources, namely Kutch, Saurashtra and Mainland Gujarat, are considered, and seismicity parameters are estimated separately for each region taking into account the completeness of the available earthquake data. Peak ground acceleration (PGA) of the horizontal component and spectral acceleration at specific periods are considered as the intensity measures. Ground motion predictive equation chosen was reported to be based on simulated ground motions and verified against the strong motion records in the study region. Results are reported for the 17 major cities at the bedrock and also for the soil sites. Apart from hazard curves, 2475 and 475 years of return periods are considered for the PGA and uniform hazard spectra (UHS). The results are compared with the present recommendations of Indian Standards. Key observations include (1) Indian Standards underpredict PGA in the entire Gujarat when the soil sites are considered and in a few cities even at the bedrock; (2) amplification of PGA (or short period hazard) on account of soil sites should be included in the Indian Standard, which is currently absent; (3) shape of the UHS indicates that a separate amplification is required at the hyperbolic portion; and (4) ratio of 2475–475 years of PGA, which is considered 2.0 in Indian Standard, should be reduced to 1.5. Time-dependent recurrence model is also included in this paper and compared with conventional PSHA. General observations include that (1) hazard may increase significantly on account of time dependency; (2) this also influences the disaggregation and in turn the selection of ground motions; and (3) time since last earthquake significantly influences the extent of the effect of time dependency.  相似文献   

4.
Soil liquefaction studies at Mumbai city   总被引：1，自引：0，他引：1  
Mumbai city is the economical capital of India and is situated about midway on the western coast of stable continental region of Peninsular India. Major part of the city being of reclaimed land, the soil type is of alluvium, sand, and recent conglomerate. There are some bigger water bodies within the city range. In this study, an attempt has been made to study the susceptibility of soil liquefaction using simplified empirical procedure based on number of blow counts (N values) of the soil layers from standard penetration test. The liquefaction susceptibility is quantified in terms of factor of safety along the borehole depths at available borehole locations using earthquake-induced cyclic stress on the soil and the cyclic resistance of the soil to withstand the load. The factor of safety against liquefaction is evaluated at different sites for two peak ground acceleration (PGA) levels pertaining to 10 and 2?% probability of exceedance in 50?years corresponding to uniform hazard response spectra for Mumbai city with 475- and 2,475-year return period, respectively. Contour maps are prepared that display the factor of safety at different depths for earthquake magnitude of M w 6.5. These contour maps show the liquefaction vulnerability at different sites in the city.  相似文献   

5.
A probabilistic seismic hazard analysis for the states of Tripura and Mizoram in North East India is presented in this paper to evaluate the ground motion at bedrock level. Analyses were performed considering the available earthquake catalogs collected from different sources since 1731–2010 within a distance of 500 km from the political boundaries of the states. Earthquake data were declustered to remove the foreshocks and aftershocks in time and space window and then statistical analysis was carried out for data completeness. Based on seismicity, tectonic features and fault rupture mechanism, this region was divided into six major seismogenic zones and subsequently seismicity parameters (a and b) were calculated using Gutenberg–Richter (G–R) relationship. Faults data were extracted from SEISAT (Seismotectonic atlas of India, Geological Survey of India, New Delhi, 2000) published by Geological Survey of India and also from satellite images. The study area was divided into small grids of size 0.05° × 0.05° (approximately 5 km × 5 km), and the hazard parameters (rock level peak horizontal acceleration and spectral accelerations) were calculated at the center of each of these grid cells considering all the seismic sources within a radius of 500 km. Probabilistic seismic hazard analyses were carried out for Tripura and Mizoram states using the predictive ground motion equations given by Atkinson and Boore (Bull Seismol Soc Am 93:1703–1729, 2003) and Gupta (Soil Dyn Earthq Eng 30:368–377, 2010) for subduction belt. Attenuation relations were validated with the observed PGA values. Results are presented in the form of hazard curve, peak ground acceleration (PGA) and uniform hazard spectra for Agartala and Aizawl city (respective capital cities of Tripura and Mizoram states). Spatial variation of PGA at bedrock level with 2 and 10 % probability of exceedance in 50 years has been presented in the paper.  相似文献   

6.
A seismic hazard map of Kanpur city has been developed considering the region-specific seismotectonic parameters within a 500-km radius by deterministic and probabilistic approaches. The maximum probable earthquake magnitude (M max) for each seismic source has been estimated by considering the regional rupture characteristics method and has been compared with the maximum magnitude observed \(\left ({M_{\max }^{\text {obs}}}\right )\), \(M_{\max }^{\text {obs}} +0.5\) and Kijko method. The best suitable ground motion prediction equations (GMPE) were selected from 27 applicable GMPEs based on the ‘efficacy test’. Furthermore, different weight factors were assigned to different M max values and the selected GMPE to calculate the final hazard value. Peak ground acceleration and spectral acceleration at 0.2 and 1 s were estimated and mapped for worst-case scenario and 2 and 10% probability of exceedance for 50 years. Peak ground acceleration (PGA) showed a variation from 0.04 to 0.36 g for DSHA, from 0.02 to 0.32 g and 0.092 to 0.1525 g for 2 and 10% probability in 50 years, respectively. A normalised site-specific design spectrum has been developed considering three vulnerable sources based on deaggregation at the city center and the results are compared with the recent 2011 Sikkim and 2015 Nepal earthquakes, and the Indian seismic code IS 1893.  相似文献   

7.
The Himalayas are one of very active seismic regions in the world where devastating earthquakes of 1803 Bihar–Nepal, 1897 Shillong, 1905 Kangra, 1934 Bihar–Nepal, 1950 Assam and 2011 Sikkim were reported. Several researchers highlighted central seismic gap based on the stress accumulation in central part of Himalaya and the non-occurrence of earthquake between 1905 Kangra and 1934 Bihar–Nepal. The region has potential of producing great seismic event in the near future. As a result of this seismic gap, all regions which fall adjacent to the active Himalayan region are under high possible seismic hazard due to future earthquakes in the Himalayan region. In this study, the study area of the Lucknow urban centre which lies within 350 km from the central seismic gap has been considered for detailed assessment of seismic hazard. The city of Lucknow also lies close to Lucknow–Faizabad fault having a seismic gap of 350 years. Considering the possible seismic gap in the Himalayan region and also the seismic gap in Lucknow–Faizabad fault, the seismic hazard of Lucknow has been studied based on deterministic and the probabilistic seismic hazard analysis. Results obtained show that the northern and western parts of Lucknow are found to have a peak ground acceleration of 0.11–0.13 g, which is 1.6- to 2.0-fold higher than the seismic hazard compared to the other parts of Lucknow.  相似文献   

8.
Indian peninsular shield, which was once considered to be seismically stable, is experiencing many earthquakes recently. As part of the national level microzonation programme, Department of Science and Technology, Govt. of India has initiated microzonation of greater Bangalore region. The seismic hazard analysis of Bangalore region is carried out as part of this project. The paper presents the determination of maximum credible earthquake (MCE) and generation of synthetic acceleration time history plot for the Bangalore region. MCE has been determined by considering the regional seismotectonic activity in about 350 km radius around Bangalore city. The seismotectonic map has been prepared by considering the faults, lineaments, shear zones in the area and historic earthquake events of more than 150 events. Shortest distance from the Bangalore to the different sources is measured and then peak ground acceleration (PGA) is calculated for the different source and moment magnitude. Maximum credible earthquake found in terms of moment magnitude is 5.1 with PGA value of 0.146 g at city centre with assuming the hypo central distance of 15.88 km from the focal point. Also, correlations for the fault length with historic earthquake in terms of moment magnitude, yields (taking the rupture fault length as 5% of the total fault length) a PGA value of 0.159 g. Acceleration time history (ground motion) and a response acceleration spectrum for the corresponding magnitude has been generated using synthetic earthquake model considering the regional seismotectonic parameters. The maximum spectral acceleration obtained is 0.332 g for predominant period of 0.06 s. The PGA value and synthetic earthquake ground motion data from the identified vulnerable source using seismotectonic map will be useful for the PGA mapping and microzonation of the area.  相似文献   

9.
A broad overview of how GPS can be used to identify the active fault plane along which earthquakes occur in the seismic prone Western Maharashtra Peninsular shield of India is given. Indian Institute of Technology, Bombay in collaboration with Indian Institute of Geomagnetism, Mumbai was actively working in the field of crustal deformation monitoring along Western Maharashtra from year 2004–2006. A regional GPS network had been established for this purpose, periodically observed between May 2004 to May 2006, and analysed. To understand the pattern of seismicity along Western Maharashtra region, the GPS-estimated coordinates and displacements were used as an indicator to estimate and identify regions of high strain rates, the reliability of which was confirmed with real seismic data collected. These strain rates were used as a means to identify the fault plane along which the earthquakes occurred during the period of observation.  相似文献   

10.
Seismic hazard studies were conducted for Gaziantep city in the South Anatolia of Turkey. For this purpose, a new attenuation relationship was developed using the data of Zaré and Bard and accelerations were predicted employing this new equation. Deterministic approach, total probability theorem and GIS methodology were all together utilized for the seismic assessments. Seismic hazard maps with 0.25° grid intervals considering the site conditions were produced by the GIS technique. The results indicated that the acceleration values by the GIS hazard modelings were matched with the ones from the deterministic approach, however, they were underestimated comparing with the total probability theorem. In addition, the GIS based seismic hazard maps showed that the current seismic map of Turkey fairly yields conservative acceleration values for the Gaziantep region. Therefore, the constructed GIS hazard models are offered as a base map for a further modification of the current seismic hazard map.  相似文献   

11.
This paper examines the variability of seismic activity observed in the case of different geological zones of peninsular India (10°N–26°N; 68°E–90°E) based on earthquake catalog between the period 1842 and 2002 and estimates earthquake hazard for the region. With compilation of earthquake catalog in terms of moment magnitude and establishing broad completeness criteria, we derive the seismicity parameters for each geologic zone of peninsular India using maximum likelihood procedure. The estimated parameters provide the basis for understanding the historical seismicity associated with different geological zones of peninsular India and also provide important inputs for future seismic hazard estimation studies in the region. Based on present investigation, it is clear that earthquake recurrence activity in various geologic zones of peninsular India is distinct and varies considerably between its cratonic and rifting zones. The study identifies the likely hazards due to the possibility of moderate to large earthquakes in peninsular India and also presents the influence of spatial rate variation in the seismic activity of this region. This paper presents the influence of source zone characterization and recurrence rate variation pattern on the maximum earthquake magnitude estimation. The results presented in the paper provide a useful basis for probabilistic seismic hazard studies and microzonation studies in peninsular India.  相似文献   

12.
In this work, an attempt has been made to evaluate the spatial variation of peak horizontal acceleration (PHA) and spectral acceleration (SA) values at rock level for south India based on the probabilistic seismic hazard analysis (PSHA). These values were estimated by considering the uncertainties involved in magnitude, hypocentral distance and attenuation of seismic waves. Different models were used for the hazard evaluation, and they were combined together using a logic tree approach. For evaluating the seismic hazard, the study area was divided into small grids of size 0.1° × 0.1°, and the hazard parameters were calculated at the centre of each of these grid cells by considering all the seismic sources within a radius of 300 km. Rock level PHA values and SA at 1 s corresponding to 10% probability of exceedance in 50 years were evaluated for all the grid points. Maps showing the spatial variation of rock level PHA values and SA at 1 s for the entire south India are presented in this paper. To compare the seismic hazard for some of the important cities, the seismic hazard curves and the uniform hazard response spectrum (UHRS) at rock level with 10% probability of exceedance in 50 years are also presented in this work.  相似文献   

13.
Chennai city suffered moderate tremors during the 2001 Bhuj and Pondicherry earthquakes and the 2004 Sumatra earthquake. After the Bhuj earthquake, Indian Standard IS: 1893 was revised and Chennai city was upgraded from zone II to zone III which leads to a substantial increase of the design ground motion parameters. Therefore, a comprehensive study is carried out to assess the seismic hazard of Chennai city based on a deterministic approach. The seismicity and seismotectonic details within a 100 km radius of the study area have been considered. The one-dimensional ground response analysis was carried out for 38 representative sites by the equivalent linear method using the SHAKE91 program to estimate the ground motion parameters considering the local site effects. The shear wave velocity profile was inferred from the corrected blow counts and it was verified with the Multichannel Analysis of Surface Wave (MASW) test performed for a representative site. The seismic hazard is represented in terms of characteristic site period and Spectral Acceleration Ratio (SAR) contours for the entire city. It is found that structures with low natural period undergo significant amplification mostly in the central and southern parts of Chennai city due to the presence of deep soil sites with clayey or sandy deposits and the remaining parts undergo marginal amplification.  相似文献   

14.
The seismically active Northwest (NW) Himalaya falls within Seismic Zone IV and V of the hazard zonation map of India. The region has suffered several moderate (~25), large-to-great earthquakes (~4) since Assam earthquake of 1897. In view of the major advancement made in understanding the seismicity and seismotectonics of this region during the last two decades, an updated probabilistic seismic hazard map of NW Himalaya and its adjoining areas covering 28–34°N and 74–82°E is prepared. The northwest Himalaya and its adjoining area is divided into nineteen different seismogenic source zones; and two different region-specific attenuation relationships have been used for seismic hazard assessment. The peak ground acceleration (PGA) estimated for 10% probability of exceedance in 50 and 10 years at locations defined in the grid of 0.25 × 0.25°. The computed seismic hazard map reveals longitudinal variation in hazard level along the NW Himalayan arc. The high hazard potential zones are centred around Kashmir region (0.70 g/0.35 g), Kangra region (0.50 g/0.020 g), Kaurik-Spitti region (0.45 g/0.20 g), Garhwal region (0.50 g/0.20 g) and Darchula region (0.50 g/0.20 g) with intervening low hazard area of the order of 0.25 g/0.02 g for 10% probability in 50 and 10 years in each region respectively.  相似文献   

15.
Cyclic mobility is a mechanism of ground failure due to lateral spreading of soils during an earthquake that usually occurs in soft or medium stiff saturated soils. The simplified procedures developed by the researchers give a factor of safety for judging the cyclic mobility potential. However, the simplified procedures do not take into account the uncertainty in the parameters required to estimate the cyclic stresses in the soil. In this study, a reliability framework based on the simplified procedure, considering the parameter uncertainty, has been proposed for computing the probability of cyclic mobility of clay deposits for a metro city of India, i.e., Mumbai city (latitudes 18°53′N–19°19′N and longitudes 72°47′E–72°58′E). Extensive geotechnical borehole data from 1028 boreholes across 50 locations in the city area of 390 km2 and laboratory test data are collected and analyzed thoroughly. A correlation between undrained shear strength (Su) and other parameters such as natural water content (w), SPT N value, liquid limit (LL) and plasticity index (PI) has been established for Mumbai city and has been used in the proposed approach. The sensitivity analysis of the proposed approach predicts that Su has significant influence in the evaluation of the cyclic mobility. Cyclic mobility hazard maps are prepared using the geo-statistical analysis tool in GIS, and it shows that the clayey soils at few locations have a 60–90 % probability of cyclic mobility for a moment magnitude (M w) of an earthquake of 7.5. These hazard maps can be used by the geotechnical engineers for the cyclic mobility hazard assessment of Mumbai city.  相似文献   

16.
A comprehensive analytical as well as numerical treatment of seismological, geological, geomorphological and geotechnical concepts has been implemented through microzonation projects in the northeast Indian provinces of Sikkim Himalaya and Guwahati city, representing cases of contrasting geological backgrounds — a hilly terrain and a predominantly alluvial basin respectively. The estimated maximum earthquakes in the underlying seismic source zones, demarcated in the broad northeast Indian region, implicates scenario earthquakes of M W 8.3 and 8.7 to the respective study regions for deterministic seismic hazard assessments. The microzonation approach as undertaken in the present analyses involves multi-criteria seismic hazard evaluation through thematic integration of contributing factors. The geomorphological themes for Sikkim Himalaya include surface geology, soil cover, slope, rock outcrop and landslide integrated to achieve geological hazard distribution. Seismological themes, namely surface consistent peak ground acceleration and predominant frequency were, thereafter, overlaid on and added with the geological hazard distribution to obtain the seismic hazard microzonation map of the Sikkim Himalaya. On the other hand, the microzonation study of Guwahati city accounts for eight themes — geological and geomorphological, basement or bedrock, landuse, landslide, factor of safety for soil stability, shear wave velocity, predominant frequency, and surface consistent peak ground acceleration. The five broad qualitative hazard classifications — ‘low’, ‘moderate’, ‘high’, ‘moderate high’ and ‘very high’ could be applied in both the cases, albeit with different implications to peak ground acceleration variations. These developed hazard maps offer better representation of the local specific seismic hazard variation in the terrain.  相似文献   

17.
The Indian subcontinent is characterized by various tectonic units viz., Himalayan collision zone in North, Indo-Burmese arc in north-east, failed rift zones in its interior in Peninsular Indian shield and Andaman Sumatra trench in south-east Indian Territory. During the last about 100 years, the country has witnessed four great and several major earthquakes. Soon after the occurrence of the first great earthquake, the Shillong earthquake (M w: 8.1) in 1897, efforts were started to assess the seismic hazard in the country. The first such attempt was made by Geological Survey of India in 1898 and since then considerable progress has been made. The current seismic zonation map prepared and published by Bureau of Indian Standards, broadly places seismic risk in different parts of the country in four major zones. However, this map is not sufficient for the assessment of area-specific seismic risks, necessitating detailed seismic zoning, that is, microzonation for earthquake disaster mitigation and management. Recently, seismic microzonation studies are being introduced in India, and the first level seismic microzonation has already been completed for selected urban centres including, Jabalpur, Guwahati, Delhi, Bangalore, Ahmadabad, Dehradun, etc. The maps prepared for these cities are being further refined on larger scales as per the requirements, and a plan has also been firmed up for taking up microzonation of 30 selected cities, which lie in seismic zones V and IV and have a population density of half a million. The paper highlights the efforts made in India so far towards seismic hazard assessment as well as the future road map for such studies.  相似文献   

18.
The planned Yunnan–Tibet railway goes through the northwest of Yunnan Province and the southeast of the Tibet Autonomous Region. Because of its location near the collision belt of the Eurasian and Indian plates, complex engineering geological conditions and difficult engineering geological problems are encountered. The study is aimed at making the zoning assessment of crustal stability along the railway line so as to provide a better base for its construction, especially its line selection. For this purpose, the following seven influencing factors of crustal stability were selected and quantified by grading and scoring: active fault, seismic activity, geo-stress field, geo-strain field, geothermal field, geo-hazard, and lithologic character. Of these factors, the active fault, seismic activity and geo-hazard are the three most prominent factors influencing the railway construction. Along the railway line there are 1731703 calculation units to be divided. The zoning assessment calculation was completed by ArcGIS-based information fusion method. The assessment results aid railway line selection and show that there are 10 stable sectors, 28 relatively stable sectors, 23 relatively unstable sectors, and 20 unstable sectors along the Yunnan–Tibet railway line.  相似文献   

19.
The aim of this study is to assess the seismic hazard in the eastern Mediterranean and Sinai region using a probabilistic approach. An updated earthquake catalogue for the period 1 to 1993 AD that covers the area between latitude 27°–37°N and longitude 32°–39°E, has been used. Using the new seismic-tectonic map for the area, 10 line-sources are delineated. These lines or fault zones are thought to represent the main sources for the seismic potential in the area. The results are demonstrated as iso-contour lines of the peak-ground acceleration. The iso-acceleration contours represent 90% probability that these peak values will not be exceeded over periods of 50, 100 and 200 years, respectively. This study concludes that the seismic hazard severity is highest along the Jordan Dead Sea transform fault system, namely from south of the Gulf of Aqaba, Dead Sea-Jordan River, Tiberia Lake, Rachaya, Ed Damur, Yammuneh Fault, and Ghab Fault in the north. For the 50 year iso-contour map, the major cities of Amman, Damascus, and Beirut lay around the 2 m s−2 contour line, while Jerusalem lies along the 3 m s−2 line. Antakia in Turkey has the highest seismic potential severity (around 5 m s−2) while in Cyprus the maximum hazard is expected to reach 4 m s−2 for the coming 50 years.  相似文献   

20.
This study presents the future seismic hazard map of Coimbatore city, India, by considering rupture phenomenon. Seismotectonic map for Coimbatore has been generated using past earthquakes and seismic sources within 300 km radius around the city. The region experienced a largest earthquake of moment magnitude 6.3 in 1900. Available earthquakes are divided into two categories: one includes events having moment magnitude of 5.0 and above, i.e., damaging earthquakes in the region and the other includes the remaining, i.e., minor earthquakes. Subsurface rupture character of the region has been established by considering the damaging earthquakes and total length of seismic source. Magnitudes of each source are estimated by assuming the subsurface rupture length in terms of percentage of total length of sources and matched with reported earthquake. Estimated magnitudes match well with the reported earthquakes for a RLD of 5.2% of the total length of source. Zone of influence circles is also marked in the seismotectonic map by considering subsurface rupture length of fault associated with these earthquakes. As earthquakes relive strain energy that builds up on faults, it is assumed that all the earthquakes close to damaging earthquake have released the entire strain energy and it would take some time for the rebuilding of strain energy to cause a similar earthquake in the same location/fault. Area free from influence circles has potential for future earthquake, if there is seismogenic source and minor earthquake in the last 20 years. Based on this rupture phenomenon, eight probable locations have been identified and these locations might have the potential for the future earthquakes. Characteristic earthquake moment magnitude (M w ) of 6.4 is estimated for the seismic study area considering seismic sources close to probable zones and 15% increased regional rupture character. The city is divided into several grid points at spacing of 0.01° and the peak ground acceleration (PGA) due to each probable earthquake is calculated at every grid point in city by using the regional attenuation model. The maximum of all these eight PGAs is taken for each grid point and the final PGA map is arrived. This map is compared to the PGA map developed based on the conventional deterministic seismic hazard analysis (DSHA) approach. The probable future rupture earthquakes gave less PGA than that of DSHA approach. The occurrence of any earthquake may be expected in near future in these eight zones, as these eight places have been experiencing minor earthquakes and are located in well-defined seismogenic sources.  相似文献   

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