Seismic Hazard Analysis For Tamil Nadu State : A Deterministic Approach
Seismic Hazard Analysis for Tamil Nadu State :A Deterministic ApproachG.P. Ganapathy* and S. Rajarathnam**AbstractTamil Nadu State, with an area of 130, OSBsq.km located in the southern most part of the PeninsularIndia Is selected for the present study on seismic hazard assessment. The part of northern andwestern Tamil Nadu State including its capital city Chennai have been categorized under ModerateSeismic Hazard (Zone III) areas, by Bureau of Indian Standard (BIS) In 2001. A catalog ofhistorical/instrumental earthquakes/ earth tremors In the state has been prepared and used inthis paper. The earthquakes having magnitude of greater than 3.0 have been considered for thepresent study. The seismic sources have been Identified using remote sensing images with limitedground truth verification. Seven near potential seismic sources in the region delineated as areasources for seismic hazard assessment based on geological, seismologlcal and geophysicalinformation. Shortest distance from the each seismic source to the major cities of Tamil Nadumeasured and the Peak Ground Acceleration (PGA) at bed rock level Is calculated for the sevensources with their maximum credible earthquake events using available attenuation relationshipformula. The maximum magnitude associated with these potential seismic sources Is in the rangeof 6.0 to 5.0 in Richter scale and the estimated on Peak Ground Acceleration at the source Is0.212 to 0.078g. The PGA values are estimated from the closest potential source for major citiesof Tamil Nadu viz., Chennai, Coimbatore, Salem, Madurai and Trichirappalll cities, which havePGA of 0.107g, 0.133g, 0.012g, 0.077g & 0.113g respectively. The result of the present studyreveals that the seismic hazard In northeastern and western part of the state Is closely matchingwith the Seismic Zonatlon map published by the BIS. However the east southeastern part of thestate shows higher value because of the adequate earthquake data used for the present study forthe years 1800 to 2004. The southern part of state shows comparatively low seismic hazard thanthe other parts of the Tamil Nadu state.Introduction„ . . ,Seismic hazard assessment is essential forcarrying out safe and economic design ofstructures Determimyic seismic hazardassessments seek to i dentify the MaximumCredible Earthquake (MCE) that will alfect asite. The MCE IS the largest earthquake thatappears possible along a recognized lauUunder the presently known or presumedtectonic activity, which will cause the rnostsevere consequences at the site. MCEassessment gives little consideration to theprobability of future fault movements.Tamil Nadu is one of the 13 identifiedseismotectonio zones of Peninsular India,, gtudy of lineaments can ending the seismicity and9 7 73number of studies carried out In India andBrahmam and Negl 1973;Khattari et al, 1988; Peshwa andRamasamy 2000; VIvek Laul,and Khanna,) and have indicated correlation between earthquakesimeaments. Research studies have beenundertaken on the seism icity of thea2 0 0 02 0 0 1'Assistant Professor, Centre for Disaster Mitigation and Management, VIT University, Vellore 632 014,Tamil Nadu, India, (E-mail: seismogans@yahoo.com)**Professor, Centre for Disaster Mitigation and Management, Anna University, Chennai 600 025, TamilNadu, India, (E-mail: dr rajarathnam@yahoo.co.ln)
Peninsular India based on the lineaments/faults with their spatial association of theepicentres of the earthquakes. Chandra(1977) identified several seismic zones belowlatitude 28 N in Peninsular India andcorrelated the epicentres with knowngeological structures and faults andconcluded that in southern India, theepicenters in seismogenic source zone havethe scatter pattern and some of them couldbe correlated with the existing faults. Strongearthquakes from Peninsular India aregenerally confined to zones with activeneotectonic movements (Srivastava 1985).Fault plane solutions of the earthquakes inKoyna, Ongole, Bhadrachalam haveindicated that the faults are of the strike-sliptype with lateral movement and reverse typein the case of Broach and Latur earthquakes(Arora et al 1971; Chandra 1976 and 1977;Rao et al 1975; Langeston 1976; Banghar1972; Rastogi 1992; Seebar et. al 1996).Recent studies carried out in Tamil Nadu andthe rest of India have revealed thatlineaments/faults have a clear spatialassociation with earthquake incidences(Rajarathnam et al 1996; Rajarathnam andGanapathy 2002; Ganesharaj et al 2001,Khanna 2001, Sitharam et.al, 2006).Out of 38 earthquakes recorded in thesouthern part of the Peninsula between 1823and 1968, 19 earthquakes have beenoccurred within 50km of the fault bearing N45 E. Six have occurred on or adjacent toArchaean - Cretaceous boundary fault inTamil Nadu. The region in which the deepmain fault occurs is seismically active at thepresent time (Grady 1971). Earthquakes ofmagnitude 6.0 had been recorded in 1900near Coimbatore. The various fault systemsin Tamil Nadu seems to be active even duringthe present day (Vemban et al 1977).Potentially seismic faults are area of sources,in which the configuration of each sourcezone is controlled mainly by the extent ofactive faults, the mechanism of earthquakefaulting and the seismogenic part of the crust.The goal of potential seismic sourceidentification is to identify and include in theanalysis of all structures (mainly faults) thatare believed to be tectonically active withfaults of even low rates of activity (EERICommittee on Seismic Risk, 1989). Thedelineation of these sources is usually themajor part of any seismic hazard analysis(Reiter, 1990). A total of 235 potential seismicsources in Iran and neighbouring region aredelineated based on available geological,geophysical, tectonic and earthquake datafor the seismic hazard assessment of thecountry (Mirzaei 1999).Tamil Nadu experienced moderateearthquakes in the past earthquake historyofyears is well evident from the publishedliteratures. Twelve earthquakes of M 5.0have occurred in the State for the known2 0 0Table 1: Seismic Potential Sources of Tamil Nadu StateSourceABCDEFGName of the Potential seismic sourcesLineament on the Northern txjundary of Palghat gap (EW) - (No.47)Nllgiris lineament (NE) - (No.44)Basement fault following the western isoundary of Thanjavore Tranquebar depression (NE-SW) - (No. 50)Lineament on the Northern boundary of Palghat gap(WNW - ESE)- (No. 49)Adayar fault (EW) - (No.31)Chengam - Aiangayam Gudiyattam lineament (NNE - SSW) - (No 21)Adanur - Thirul ovilur- Ponnaiyar lineament (NE-SW) - (No.26)Note : For details on fault number in bracket, refer Fig.1.L: Length of ttie seismic potential source in KmCE: Cumulative Number of Earthquakes: Magnitude observed from the historic/instrumental earthquakePGA : Peak Ground Acceleration (PGA) in g determined 625.00.07842160135.35.00.1070.0784535.00.078
history. Bureau of Indian Standard (2001)categorized Tamil Nadu under Seismic ZonesII and III, representing an area of 73% and27% respectively. It should also to be notedthat the major cities in Tamil Nadu viz.,Chennai, Coimbatore and Salem fall in Zoneill. Many researchers have carried out studieson seismicity of Tamil Nadu based oncorrelation of earthquake epicenters with thetectonic set up of the region. It is very muchessential to know the potential seismichazard of the state. The present study aimsat producing seismic hazard maps in termsof Peak Ground Acceleration for Tamil NaduState.Fig. 1: Seismic Prone Lineaments of Tamil Nadu State
Seismo-tectonic set-up of Tamil NaduGeology of the Study AreaDetailed knowledge of geology, active faults/lineaments and associated seismicity isrequired to quantify seismic hazard. Theinfonnation on past earthquakes gives an ideaof the seismic status of a place or region.The study requires a variety of geological andseismological information such as details ofepicentres, origin time, focus, depth, andmagnitude and fault systems to identify thecurrently active faults (Tandon 1992).Seismotectonic details have been collectedfor the study area lies between latitudes08 00’00”N and 13 30’00”N and longitudes76 15’ 00”E and SO I ’ 00” E.The Geology of Tamil Nadu State representsa shield inland (85%) and 15% is thebasement of the Cauvery basin in the eastcoast of Tamil Nadu forms the present studyarea (Fig.1). The shield area of Tamil Naduconsists of charnockites and gneisses withintrusive complexes viz., carbonatite, dolerite,syenite and granite. The Cauvery basin hasthick successions of sedimentary formationsof Mesozoic to Cenozoic eras. The basincame into being in the above region as a pullapart following the rift along the easterncontinental margin of the Indian sub continentin the early Mesozoic era (Kumar 1983).8
LineamentsBased on the satellite imagery, 257lineaments have been identified. On the basisof distribution of lineaments Tamil Nadu hasbeen broadly classified into North and SouthBlocks in the inland area and Coastal Blocl in the east coast. The Cauvery river courseis the boundary in the inland area betweenthe North and South Blocks (Fig.1). Amongstthe selected 257 lineaments, 85% fall in theNorth Block and 15 % in the South Block(Rajarathnam and Ganapathy,2002).In the North Block the lineaments have trendsof NE - SW, NNW - SSE, N S and E Wdirections and in the South Block, thelineaments trend in NW - SE and NE -SWdirections. The density of lineaments iscomparatively more in the North than in theSouth Block.The NE-SW lineaments are mega lineaments100 km in length and NNW -SSE lineamentsare intermediate lineaments around 50km inlength as described by Gold (1980). The NESW lineaments are widely distributed and areFig. 3; Map showing the Seismic Hazard for Tamil Nadu State in term s of Peak Ground Acceleration
parallel to the trend of Eastern Ghats. Thewest of South Block represents NNW - SSElineaments parallel to the trend of WesternGhats. The prominent lineament trendsrecognized in this Block are WNW-ESE,NNW-SSE and NW-SE. The NNW -NW toSSE - SW system lineaments can begenerally related to the west coast fault(Ganesharaj et al., 2001). The WNW -ESElineaments parallel to trend of Palghat Gapis a prominent break in the Western Ghat.The Palghat Gap represents parallel faults.The identified mega and intermediatelineaments are the result of the stress andstrain caused by the onward thrust of theIndian Plate against the rigid Asian Plate.In the Coastal Block of Tamil Nadu, theboundary fault recognized on surfaceseparates Crystalline and Sedimentaryformations and all others in the Block are ofthe horst and graben systems. These areidentified mainly from gravity and reflectionseismic geophysical data. Evidences fromdrilled wells by Oil and Natural GasCorporation (ONGC) confirm their presencealso. The regional alignment of the tectonicfeatures is NE-SW, parallel to the EasternGhat trend. The basement has horst andgraben morphology resulting from faults withconsiderable throw. The various tectonicfeatures, which have been recognized areA riyalur-P ondicherrydepression,Kumbakonam ridge, Thanjavur depression,Tranquebar depression, DevakottaiMannargudi ridge, Nagapattinam depression,Ramnad - Palk Bay depression, Mannardepression and Mandapam ridge. Thesedepressions are broad and occupy largerareas compared to the ridges, which are innarrow zones. Most of these tectonic featuresextend into the offshore areas. The sedimentthickness in the depressions varies from 4000to 7000 metres. The ridges have sedimentsin the range of 1000 to 2000 metres. Themaximum thickness of 7000 metres is in theAriyalur-Pondicherry depression (Kumar,1983). These fault systems have commenceddeveloping in Late Proterozoic period with theTable 2. Estimated Peak Ground Acceleration (PGA) values at major cities of Tamil Nadu by thedifferent potential seismic ce forLineament/FauttNameLineament on theNorthern boundaryof Palghat gap(EW) - (No.47)Nilgiris lineament(NE)-(No.44)Basement faultfollowing thewestern boundaryof Thanjavore Tranquebardepression (NESW) - (No. 50)Lineament on theNorthem boundaryof Palghatgap(WNW - ESE)- (No. 49)Adayar fault (E W )(No.31)Chengam AlangayamGudiyattamlineament (NNE S S W )-(N o .21)AdanurThirukovilur*Ponnaiyarlineament (NE-SW)- (No.26)PGA atSourceEpicentral Distance from the source to MajorPeak Ground Acceleration at Major CitiesCitiesMaximumMagnitudCoimbatorTrichiraChenna CoimbatorSalem Madurai Trichi rapalliSalem MaduraiChennaie 225762311260.0010.0780.0090.0060.006Note: For details on fault number in bracket, refer Fig.1.
initiation of the breakup of Gondwana landand characterized by large-scale verticalmovements (Gopalakrishnan, 1996).SeismicityA number of catalogues of past Indianearthquakes are available but none of themis up to date and comprehensive. The earliestpublication is by Oldham (1883) which givesa list of significant Indian earthquakes upto1869. Gubin (1968) published a list ofsignificant earthquakes in Peninsular India.Tandon and Srivastava (1974) published acatalogue of earthquakes in India of M 5.0and above based on historical andinstrumental and macro-seismic dataavailable before 1970. Chandra (1977)compiled a list of earthquakes up to 1975from different sources.In order to understand the seismicity of TamilNadu, data regarding past earthquakesM 3.0 have been collected for a period ofaround 200 years (1807 - 2002) from varioussources (Seismic Array of Gauribindanur,Babha Atomic Research Centre (BARC),Karnataka State, National GeophysicalResearch Institute (NGRI), Hyderabad, IndiaMeteorological Department (IMD), New Delhi,Bansal and Gupta 1998, Chandra 1977,Srivastava and Ramachandran 1985). Thedetails of micro-tremors with magnitude of2.0-3.0 from BARC publications areincorporated for 12 years from 1977 to 1988(Gangrade et al 1987 and 1989). Themaximum number of earthquakes identifiedfrom these sources for the present study is103. The spatial locations of earthquakeepicentre (latitude and longitude), withcon’esponding magnitude are depicted in Fig.1.Out of the total 103 earthquakes/earthtremors 48,23,21,10 and 1 event have beenin the magnitude range of 2.0 - 2.9, 3.0 3.9,4.0 - 4.9,5.0 - 5.9 and 6.0 respectively.52 earthquakes (51 % of overall) are of M 3in the pastyears of seismic history.Earthquakes of M 5 are distributed aroundChennai, Villupuram, Ooty, Coimbatore and2 0 0Pondicherry - Off the Coast. The M 4 to 4.9earthquakes are distributed, apart from abovesaid areas, around Tiruppattur, Dharmapuri,Salem, Coimbatore, Trichirappalli, andMadurai areas (Fig. 1). M 2.0 to 3.9earthquakes are distributed in northerneastern and southern part of Tamil Nadu.The available seismic data have been plottedover a map representing 257 lineaments andthe major percentage of the epicentres isaligned along with the NE-SW and NW-SEtrend of lineaments. A few of them fall on theE-W and N-S trend of lineaments. Thespatial association of epicenters withlineaments is categorised as seismic pronelineaments. The length of those lineamentsis ranged from 10km to 315km.Seismic Hazard AnalysisSeismic Hazard analysis models theoccurrence of earthquakes on seismicsources. These sources may range frombroad aerially distributed source zones todiscrete three-dimensional units. The basicalgorithm for seismic hazard analysis iscreated on the premise that the earthquakewould occur randomly within a seismicsource. The distance from the seismicsource to the site is obviously importantbecause attenuation would depend on it. Insearch of the seismic source, the firstconsideration goes to mapping the knownfaults or those which could be inferred toexist. Since the faults are spatiallydistributed in three dimensions, their detailedmapping is critically important for faults closeto a site. Spatial pattern of seismicity willhelp link seismic source zones with faults.The study on Seismic Hazard Assessmentfor Tamil Nadu carried out based onDeterministic Approach. The present studyinvolving three principal tasks 1) Identificationof potential seismic sources, 2) Estimationof maximum magnitude (M ) and ill)Estimation Peak Ground Acceleration (PGA).The methodology involved is detailed in thefollowing paragraphs.
Identification of Potential Seismic SourcesThe present study prefers the model potentialseismic sources as areas in whichconfiguration of each source zone iscontrolled, mainly by the fault extent,seismogenic crust (a part of the earth crustin which large earthquakes usuallynucleates), and mechanism of earthquakefaulting or type of active faults.For the width of seismic source (rupturewidth) researchers have taken 30 km forthrust fault zones andkm for strike slipfaulting. Since crustal thrust and reversefaults seldom occur individually, they aregenerally part of imbricate or overlappingsystems made up of multiple faults and folds(Carver and Me Caplin, 1996), the width ofthe seismic source zone is wider dependingupon the individual cases.20The potential seismic sources of Tamil Naduare delineated based on the geophysical andgeological characteristics of the seismicsources along with the prevailing faultsystems in the region. The association ofcum ulative number of epicentres ofearthquakes or higher magnitudeearthquakes on the respective activelineaments/faults has also been considered.Seven potential sources have been identifiedfor the present study. These seven seismicsources have generated earthquakes in themagnitude range of 5.0 to 6.0 (sources A toG). The details are given in Table 1.For the present study the rupture width of 20km was considered assuming that the faultextended to the base of the seismogeniccrust. Using create buffer tool in the Arc-GISsoftware buffer was created for a km widthto the identified 7 seismic sources (Fig.2).2 0Prognosis of Most Credible EarthquakeIn deterministic analysis, it is more commonto define the maximum earthquake which isreasonably expected as the maximumcredible earthquake. This earthquake isbased on an evaluation of the processes,which are reasonably expected to beassociated with an earthquake source. Themaximum magnitude is an important variablein calculating the seismic hazard because itdetermines the strain energy released inlarger earthquakes.For the sources with the record of largeearthquakes (M 6.0), if the largestearthquake has occurred in a historical timeperiod, the observed largest magnitude istaken as the upper bound magnitude directly,or an increment of 0.5 to 1.0 magnitude unitis added based on frequency and accuracyof earthquake records in the source zone(Mirzaei et al 1999).In the present study for the largestearthquake which occurred in a historical/instrumental time-period with good accuracyof the recorded event was considered asmaximum possible magnitude in the potentialseismic sources (Fig.2).Estimation of Peak Ground AccelerationThe Peak Ground Acceleration (PGA) for TamilNadu due to the identified potential sourcesA,B,C,D,E,F&G has been calculated usingthe attenuation relation developed for SouthIndia by Iyengar and Raghukanth (2004). Theattenuation relation used to calculate PGAis given below;In y c1 c2(M-6) c3(M-6)2- In R -c4R In eWhere y refer to Peak Ground acceleration(PGA) in g, M refer to magnitude and R referto Hypocentral distance. Since PGA isknown to be attributed nearly as a lognormalrandom variable In y would normallydistributed with the average of (In ) beingalmost zero. Hence with e I, coefficients forthe southern region are (Iyengar andRaghukanth, 2004):c1 1.7816; c2 0.9205; c3 -0.0673; c4 0.0035; (Ine ) 0.3136 (taken as zero)The determined PGA value for the identifiedseven seismic potential sources of Tamil Naduis in the range of 0.212g to 0.078g. Themaximum PGA of 0.212 would be caused by
the lineament on the northern boundary ofPalghat Gap (Fig.2). The source is about20knfi from the Coimbatore City. Thislineament has been associated with 5earthquake incidences in the pastyearearthquake history and the Maximummagnitude (Mmax) so far generated is 6.0.The trend of the source in east west directionrunning with a length ofkm starting fromnorthern part of Kerala state and entering thewestern part of the Tamil Nadu (Fig.2). Thedetails of PGA for the twelve potentialsources are given in Table 1. The estimatedPGA at major cities of Tamil Nadu viz.,Chennai, Coimbatore, Salem, Madurai andTrichirapalli of Tamil Nadu due to the sevenseismic sources are given in Table 2.2 0 08 6To calculate hazard in the area, a grid isformed dividing each degree of latitude andlongitude in to three parts. Arc-GIS layouttool is used to perform the grid analysis.Each intersection of the grid is measuredfrom the different seismic sources and usingMicrosoft-Excel the PGA value each point iscalculated. By using this method a databasewas prepared for each seismic source, andcontours were plotted for all seven seismicsource.To evaluate the combined seismic hazard ofTamil Nadu due to the potential sources, anattempt was made in Arc-GIS Spatial AnalystSoftware. The PGA of each potential sourceplotted over the State Digital AdministrativeBoundary of Tamil Nadu and interpolated forthe assigned value to bring out the combinedseismic hazard of Tamil Nadu State (Fig.3).DiscussionsThe epicenters of earthquakes are related tothe fault system in a region. From this study,the possibility of correlation between theepicenters of earthquakes and the faultsystems has been explored to distinguishbetween the seismic prone and non-seismicprone crustal fractures.From the available ground truths and literaturepublished so far, the occurrences of variousintrusive complexes and 103 epicenters ofearthquakes (Magnitudes 2.0 - 3.0,3.0 - 4.0,4.0 4.9, 5.0 - 5.9, 6.0 and above) wereplotted on those lineament map and 59seismic-prone lineam ents/faults weredelineated out of the identified 257lineaments of Tamil Nadu. The N 30 -50“ E,N 10'’-40 W and east west lineaments areprominent lineament directions.Out of 59 seismic prone lineaments, 43lineaments/faults have spatial associationwith 91 epicentres of earthquakes and the16 lineaments closely spaced withepicentres. The balance 12 epicentres fall inblind faults zones, so those areas need tobe studied in detail. This indicates a positivecorrelation between distribution of lineamentand earthquake occurrences. The distributionof lineaments, epicentres of earthquakes andintrusive complexes confirm that the northernpart of Tamil Nadu has a higher seismicactivity than the southern part of the State.The present study involves computation ofPeak Ground Acceleration (PGA) at bedrocklevel, using the deterministic approach tounderstand the seismic hazard assessmentof Tamil Nadu. The study area was dividedinto seven seismic sources (Table 1 andFig.3) for which seismic hazard analysis wascarried out using the seismicity data of thearea from 1807 to 2004.The seven sources have generatedearthquakes in the magnitude range of 5.0to 6.0 (Sources A to G). Among the sevenseismic sources, the lineament on thenorthern boundary of Palghat Gap (SourceA) and the Nilgiris lineament (Source B) arecapable of producing the observed magnitude6.0 and 5.7 based on the fault rupture area.The ground motions were calculated in termsof Peak Ground Acceleration (PGA) atbedrock level. The estimated maximum PGAfrom the seven seismic sources was in therange of 0.212g to 0.078g (Table 1 and Fig.3).The PGA values are estimated from theclosest potential sources for major cities ofTamil Nadu. Chennai, Coimbatore Salem,
Madurai and Trichkappalli have PGAof 0.107g0.133g, 0.012g, 0.077g, and 0.113grespectively (Table 1).The whole western part of the study area isrepresented by the Western Ghat and hasmaximum PGA of 0.212g. The eastern partof the study area is represented by coastalareas and has medium level PGA in the rangeof 0.145 g to 0.107g (Fig.2). The northernpart of the study area has PGA of 0.07g. Thesouthern part of the Tamil Nadu state haslower magnitude of earthquake and lowerwould be the PGA value. This confirms thatsouthern part of Tamil Nadu is less seismicprone than the other part of the State.The contour of PGA values generated by thedifferent potential sources indicates theanticipated PGA of various cities/towns ofTamil Nadu. The estimated PGA at variousmajor cities of Tamil Nadu viz., Chennai,Coimbatore, Salem, Madurai andTrichirappalli due to the seven seismicsources are given in Table 1.The Chennai city has maximum estimatedPGA of 0.107g, which can be generated bythe seismic source E. Coimbatore city whichis close to seismogenic source A has a PGAof 0.133g. Salem has a maximum PGA of0.0113g from the seismic source C. The citiesof Madurai and Trichirapalli have maximumof observed PGA in the range of 0.077 and0.113g which generated by the seismicsource C (Table ).State.The resultant combined seismic hazard dueto the identified seismogenic sources of thestate reveals that there would be an extraattention required in for the east-southeasternand northern part of Tamil Nadu in the futureresearch studies. The major cities of TamilNadu viz., Chennai, Coimbatore, andTrichirapalli have higher peak groundacceleration values. It is essential to have adetailed micro-seismic zonation studies forthose highly and densely populated majorcities.AcknowledgementsThe first author acknowledges all facilitiesprovided by Mr.G. Viswanathan, Chancellor,VIT University, Vellore to carryout second partof the present study. The authors are gratefulto Dr. R.K. Bhandari, Founder & Chairman,Centre for Disaster M itigation andManagement, VIT University, Vellore for hisconstant encouragement, critical commentsand valuable suggestions for the improvementof this manuscript. Many thanks are to Dr.A.R.Chandrasekaran, Former Professor, NTRoorkee and Dr. TVSR. Appa Rao, FormerDirector, SERC, Chennai for their review.References1.Allen C.R ; (1975) ; Geological criteria forevaluating seismicity of Peninsular India,Geological Society of America Bulletin, Vol.86, pp. 1041-1057.2.Arora S.K., Nair J.G., and Varghese T.G.A.(1971) : Broach earthquake of March 23,1970, Earthquake Note Vol.42, No. 2,pp.17 - 263.Banghar A.R. (1972): Focal mechanism ofIndianearthquakes,BulletinofSeismologicai Society of America, Vol.6,pp.603 - 608.4.Bansal B.K., and Gupta S. (1998): A glancethrough the seismicity of Peninsular India,Journal of Geological Society of India, Vol.52, pp.67 - 802ConclusionsThe results of the present study reveal thefacts that the seismic hazard north easternand western part of Tamil Nadu is closelymatching with the regional seismic zonationprepared by Bureau of Indian Standard, 2002.However the east southeastern and northernpart of the state show higher value becauseof the adequate earthquake data used untilthe year 2004 and the frequent earthquakeactivity in the northern part of the state. Thesouthern part of state shows lower seismichazard than the other parts of the Tamil Nadu
5.6.Bureau of Indian Standard (BIS) : 1893(2001). Indian Standard, C riteria forearthquake resistant design of structures,Bureau of Indian Standards, New DelhiCarver G.A., and Me Caplin J.P. (1996) :Palaeoseisnfiology of compressionaltectonic environments. In; Me Caplin J.P.(ed) Palaeo seismology, Academic Press,Inc, San Diego, California, pp. 183 - 270.India, Vol.12, No.1, pp. 57 - 6215. Gubin I.E. (1968) : SeismicIndian Peninsula, BulletinInstitute of SeismologyEngineering, Vol. 5, pp. 109zoning of theInternationalEarthquake- 13916. Iyengar R.N and Ragukanth S.T.G, (2004):Attenuation strong ground Motion inPeninsular India, Seismological ResaerchLetters, 75, 4, p. 530-540.7.Chandra U. (1976) : Focal mechanism ofKoyna, India earthquake of 1967December 10, Geophysics Journal, Vol. 46,pp.247 - 251.17. Khanna V. K. (2001); Jabalpur earthquakeof 17 October 2002, Journal of GeologicalSociety of India, Vol.57, pp. 84.8.Chandra U. (1977) : Earthquakes ofPeninsular India - A Seismo-TectonicStudy, Bulletin of the seismological Societyof America, Vol.67, No.5, pp. 1387 - 1413.18. Khattari R.N., Ramesh Chander., GaurV.K., Sarkar I., and Sushil Kumar (1988) :New seismological constraints on thetectonicsofGarhwalHimalaya,Tectonophysics, Vol. 109, pp. 210 - 225.9.EERI Committee on Seismic Risk (1989) :The basic of seismic analysis. EarthquakeSpectra, Vol. 5, pp.675 - 70210. Ganesharaj K., Paul M.A., Hedge V.S., andNijagunappa R.(2001) : Lineaments andseismicity of Kerala - A remote sensingbased analysis. Journal of Indian Societyof Remote Sensing Vol.29, No.4, pp. 203 211 .11. GangradeB.K.,PrasadG.G.V.,Unnikrishnan E., Chandrasekar B.,Subbaramu K.R., and Sharma R.D. (1989);Earthquakes from Peninsular India: Datafrom the Gauribindanur seismic array, fromthe period January 1987 to December1988, B.A.R.C. 1454.12. Gangrade B.K., Prasad G.G.V., and SharmaR.D. (1987): Earthquakes from PeninsularIndia: Data from the Gauribindanurseismic array. Bhabha Atomic ResearchCentre, Bombay, B.A.R.C., 1347 and 1385.13. Gopalakrishnan K. (1996) : Lineamenttectonics and its relation to seismic activityin Tamil Nadu, India, Proceedings of theInternational Conference on Disasters andMitigation, Anna university. Vol. I, pp. A1-19-A1-2514. Grady J.C. (1971) : Deep main faults ofSouth India, Journal Geological Society of19. Kishor Jaiswal and Ravi Sinha (2007) :Spatial variation of maximum consideredand design basis earthquakes inPeninsular India, Current Science Vol. 92,No. 5, pp. 639 - 645.20. Krishna Brahmam N., and Negi J.G. (1973): Rift valleys beneath deccan traps (India),Bulletin Geophysical Research, Vol. 11, pp.207 - 223.21. Kumar S.P. (1983) : Geology andhydrocarbon prospects of Krishna,Godavar
Committee on Seismic Risk, 1989). The delineation of these sources is usually the major part of any seismic hazard analysis (Reiter, 1990). A total of 235 potential seismic sources in Iran and neighbouring region are delineated based on available geological, geophysical, tectonic and earthquake data for the seismic hazard assessment of the
Seismic hazard parameters are estimated and mapped in macro level and micro level based on the study area. The process of estimating seismic hazard parameters is called seismic . maps of Indian Regions earlier, based on several approaches. This includes probabilistic seismic hazard macrozonation of Tamil Nadu by Menon et al. (2010), Seismic .
This analysis complied with these provisions by using the USGS 2014 National Seismic Hazard Map seismic model as implemented for the EZ-FRISK seismic hazard analysis software from Fugro Consultants, Inc. For this analysis, we used a catalog of seismic sources similar to the one used to produce the 2014 National Seismic Hazard Maps developed by .
closure of the only Tamil secondary school in Singapore (i.e. Umar Pulavar Tamil High School) in 1982, signalled the end of Tamil medium schools where Tamil was taught as a first language. Tamil as a Second Language in English Schools The teaching of Tamil as a Second Language (TL2) il). English schools was introduced only after 1951.
To develop the seismic hazard and seismic risk maps of Taungoo. In developing the seismic hazard maps, probabilistic seismic hazard assessment (PSHA) method is used. We developed the seismic hazard maps for 10% probability of exceedance in 50 years (475 years return period) and 2 % probability in 50 years (2475 years return period). The seisic
Peterson, M.D., and others, 2008, United States National Seismic Hazard Maps ․ Frankel, A. and others, Documentation for the 2002 Update of the National Seismic Hazard Maps ․ Frankel, A. and others, 1996, National Seismic Hazard Maps Evaluation of the Seismic Zoninig Method ․ Cornell, C.A., 1968, Engineering seismic risk analysis
dominate estimates of seismic hazard in the vicinity of their traces. Figure 7c shows the seismic hazard maps after overlaying seismic hazard estimates for the faults on the map based on instrumental data. At 10% probability of exceedance, the area with the highest level of seismic hazard falls within the SSA and between the LJF and the SCF.
seismic hazard maps, the NEHRP Recommended Provisions seismic design maps, site effects, directionality effects, and the NEHRP Recommended Provisions response spectrum. FEMA 451B Topic 5a Notes Seismic Hazard Analysis 2 Instructional Material Complementing FEMA 451, Design Examples Seismic Hazard Analysis 5a - 2
The book has evolved as the textbook for a course taught to a mostly undergraduate audience over a number of years in the Department of Linguistics at UCLA. The course meets in lecture for four hours per week, with a one hour problem-solving session, during a ten-week term. The ideal audience for this book is a student who has studied some linguistics before (and thus has some idea of what .
