documentp

Use of Seismotectonic Information for the Seismic Hazard Analysis for Surat City, Gujarat,

India: Deterministic and Probabilistic Approach

T. P. THAKER,1 GANESH W. RATHOD,1 K. S. RAO,1 and K. K. GUPTA1

AbstractSurat, the financial capital of Gujarat, India, is a

mega city with a population exceeding five millions. The city falls

under Zone III of the Seismic Zoning Map of India. After the

devastating 2001 Bhuj earthquake of Mw 7.7, much attention is

paid towards the seismic microzonation activity in the state of

Gujarat. In this work, an attempt has been made to evaluate the

seismic hazard for Surat City (21.170 N, 72.830 E) based on the

probabilistic and deterministic seismic hazard analysis. After col-

lecting a catalogue of historical earthquakes in a 350 km radius

around the city and after analyzing a database statistically, deter-

ministic analysis has been carried out considering known tectonic

sources; a further recurrence relationship for the control region is

found out. Probabilistic seismic hazard analyses were then carried

out for the Surat region considering five seismotectonic sources

selected from a deterministic approach. The final results of the

present investigations are presented in the form of peak ground

acceleration and response spectra at bed rock level considering the

local site conditions. Rock level Peak Ground Acceleration (PGA)

and spectral acceleration values at 0.01 s and 1.0 s corresponding

to 10% and 2% probability of exceedance in 50 years have been

calculated. Further Uniform Hazard Response Spectrum (UHRS) at

rock level for 5% damping, and 10% and 2% probability of

exceedance in 50 years, were also developed for the city consid-

ering all site classes. These results can be directly used by

engineers as basic inputs in earthquake-resistant design of struc-

tures in and around the city.

Key words: Seismotectonics, PSHAs, DSHAs, PGA,

Response spectrum, Earthquakes, Gujarat.

1. Introduction

Peninsular India (PI) has been considered to be a

stable continental region (SCR), which has, never-

theless, experienced many strong to moderate

earthquakes since the 18th century (RAO and RAO,

1984; RAO, 2000). Some of the major earthquakes

reported in PI include, the Mahabaleshwar (1764),

Kutch (1819), Dammoh (near Jabalpur, 1846), Mount

Abu (1848), Coimbatore (1900), Son-valley (1927),

Satpura (1938), Anjar (1956), Koyna (1967), Broach

(1970), Killari (1993), Jabalpur (1997), and recently,

Bhuj (2001) earthquakes. MANDAL et al. (2000)

highlighted that during the last four decades, PI has

experienced moderate seismic activity.

The city of Surat is located in Peninsular India on

the banks of the River Tapi. As of 2007, Surat and its

metropolitan area have a population of more than five

million people. In recent times, the city has emerged

as a hub for chemicals, minerals, textiles, engineer-

ing, oil and port based industries. Surat has

infrastructure and a conducive environment for

industrial growth making it one of the most indus-

trialized cities of India. Even for moderate

earthquakes, Surat is vulnerable due to the presence

of varied kinds of structures found on soft soils of

varying thicknesses. The seismic zoning map of India

(BIS: 18932002) marks the region in zone III, which

shows basic peak ground acceleration (PGA) of

0.16 g. Such a broad zoning is too simplistic because

seismic hazard is known to have considerable spatial

variability even at shorter wave lengths. Engineering

approaches to earthquake resistant structural design

will be successful when the forces due to future

shocks are accurately estimated at the location of a

given structure. Moreover, in an historic city like

Surat, it is not just new construction that has to be

designed safe, it is equally important to protect the

existing monuments, industrial and infrastructural

facilities. Considering all aspects, seismic studies

have become very vital for the region.

In this study, an attempt has been made to esti-

mate seismic hazard at bedrock level in terms of PGA

1 Department of Civil Engineering, Indian Institute of

Technology Delhi, Hauz Khas, New Delhi 110016, India. E-mail:

[email protected]; [email protected]; raoks@civil.

iitd.ac.in; [email protected]

Pure Appl. Geophys. 169 (2012), 3754

2011 Springer Basel AGDOI 10.1007/s00024-011-0317-z Pure and Applied Geophysics

and spectral acceleration (Sa) using state of the art

probabilistic seismic hazard analysis (PSHA). A new

seismotectonic map of the study area considering

350 km radius around Surat city has been prepared

for this purpose, which consists of the past earth-

quake data (collected from various sources and

available literature) and earthquakes associated with

these tectonic sources. Available earthquake data is

analysed statistically and a recurrence relationship

has been obtained using G-R (GUTENBERG and RICH-

TER, 1944) method. Bed rock level PGA and Sa

values at 0.01 and 1.0 s corresponding to 10% and

2% probability of exceedance in 50 years; have been

calculated for Surat city. Further, Uniform Hazard

Response Spectra (UHRS) at rock level for 5%

damping and 10 and 2% probability of exceedance in

50 years were also developed for the city considering

all site classes as per the National Earthquake Hazard

Reduction Program (NEHRP) (BSSC, 2001). These

spectral accelerations and uniform hazard spectra can

be used to assess the design forces and also to

develop the design spectra for important structures.

2. Study Area

The seismic zonation studies started in 1959 by

TANDON (1956) and KRISHNA (1959) demarcate areas

of potential earthquake damage in the Indian sub-

continent. The intensity-based mapping of the Indian

Subcontinent was presented by GUHA (1962) and

GUBIN (1968). The probabilistic seismic hazard

studies for this area were done by several researchers

including BASU and NIGAM (1977), KAILA and RAO

(1979), KHATRI et al. (1984), JAISWAL and SINHA

(2006, 2007) and VIPIN et al. (2009). The study area

considered for the present investigation covers an

area of 350 km radius around the city as per regula-

tory guide 1.167 (1997). Other details such as

regional geology and seismological details for the

study area have been collected from an extensive

literature review.

The study area consists of the centre point at Surat

city with latitude 21.17 N and longitude 72.83 E,with a radius of 350 km around. This area covers the

latitude from 18.00 N to 24.32 N and longitude of69.45 E to 76.20 E and covers a major part of

Gujarat state, southern part of Rajasthan, western-

central part of Madhya Pradesh and part of Maha-

rashtra state including Mumbai city. According to the

seismic zoning map of India, the whole study area

falls into zones II to V. The major area of Kutch

district falls in zone V, the other part of Kutch district

and some part of Surashtra falls in zone IV, and the

rest of Gujarat, Maharashtra and Madhya Pradesh

falls in zone III; some areas of Rajasthan, Maha-

rashtra and Madhya Pradesh fall in the zone II of BIS

1893:2002. The study area marked in the seismic

zoning map of India is shown in Fig. 1.

3. Seismic Characteristics of the Region

Surat city, which lies along the west coast of

India, is in the stable continental region of PI.

Cambay, Rann of Kutch and Narmada-Tapti regions

are recognised as one of the most active regions of PI.

In the recent past, many researchers have addressed

the seismicity of PI (KAILA et al. 1972; CHANDRA,

1977; RAO and RAO, 1984; KHATTRI, 1992; IYENGAR

and RAGHUKANTH, 2004; SITHARAM and ANBAZHAGAN,

2007; VIPIN et al. 2009). GUHA and BASU (1993) have

compiled a catalogue of PI earthquakes of magnitude

C3. RAO and RAO (1984) fitted the frequency mag-

nitude relationship for PI. They demonstrated that the

interval 18701920 had been the period of quies-

cence, whereas prior to and after this time window, PI

showed higher levels of seismic activity. JAISWAL and

SINHA (2008) reported that most of the historical

earthquakes in PI have been concentrated near the

weak rifting zones (Rann of Kutch, Narmada linea-

ment) or in the passive continental margins (both

eastern and western), whereas the cratonic zones

(northern and eastern) and inactive grabens are gen-

erally free from large earthquake activity and thus

form stable shields within the Indian plate.

The earthquake catalogue for this area was pre-

pared by combining and consolidating the available

information from different sources covering the time

period 18182008. The earthquake data were col-

lected from different sources, i.e., Geological Survey

of India (GSI), Indian Meteorological Department

(IMD), International Seismological Centre (ISC),

National Geophysical Research Institute (NGRI),

38 T. P. Thaker et al. Pure Appl. Geophys.

Gujarat Engineering Research Institute (GERI),

Institute of Seismological Research (ISR), and United

States Geological Survey (USGS). In addition to that,

a few more data were collected from the catalogues

published by different researchers like CHANDRA

(1977); OLDHAM (1883); MALIK (1999) and JAISWAL

and SINHA (2005).

The data collected were carefully analyzed to

remove the repetitions. In some cases the magnitudes

of the same event reported by different agencies were

slightly different and in those cases, a higher mag-

nitude event has been selected for the analysis. The

data obtained were in different magnitude scales and

some of the literature only report the intensity value

for historical earthquakes. Estimation of seismic

hazard values in any region requires complete details

of past earthquakes with a uniform magnitude scale

and hence these data were converted to a common

scale of moment magnitude (Mw) as per KANAMORI

(1983) and HEATON et al. (1986), maximum value has

been adopted. In addition to that the intensity values

are converted using the empirical relation (M = (2/3)

I ? 1) by GUTENBERG and RICHTER (1956), where I is

the earthquake intensity value. Hence, in the present

context, the term magnitude refers to moment mag-

nitude (Mw) in the text here after.

About 464 earthquake events were collected with

minimum magnitude of 3.0 and maximum of 7.7.

After removing the dependent events, the data set

contains 150 events between magnitude 3 and 3.9, 111

Figure 1Study area and seismic zonation map of India (Modified from BIS 1893:2002)

Vol. 169, (2012) Use of Seismotectonic Information for the Seismic Hazard Analysis 39

Figure 2Histogram of earthquakes in study area

Figure 3Seismotectonic map of study area


events between 4 and 4.9, 36 events between 5 and 5.9

and 4 and 2 events of between magnitudes 66.9 and

more than 7.0 respectively. The number of earth-

quakes reported in each decade is shown in Fig. 2.

4. Generation of a Seismotectonic Map

The seismic sources in the study area were iden-

tified from the Seismotectonic Atlas (SEISAT, 2000),

published by the Geological Survey of India (GSI).

The base map of the area has been collected from the

United States Geological Survey (USGS). Earthquake

data and seismic sources, like major faults and line-

ament are superimposed on it. The seismotectonic

map of 350 km radius around Surat city along with the

details of earthquakes is shown in Fig. 3. A total of 17

sources identified in the study area out of which 12 are

major faults and five are major lineaments. The

lengths of seismic sources vary from 105 to 550 km.

5. Deterministic Estimation of Peak Ground

Acceleration

Deterministic seismic hazard assessments seek to

identify maximum credible earthquake (MCE) that

will affect the site. The MCE is the largest earthquake

that can be reasonably expected to occur in the region

(KRINITZSKY, 2002). It can be obtained by the deter-

ministic method (KRINITZSKY, 2002). In the present

study, vulnerable sources refer to the sources that are

capable enough to produce significant magnitude of

earthquake. Hence, those sources produce the earth-

quake magnitude of 4.0 and above have been

considered in the analysis, are listed in Table 1.

Maximum magnitude has been assigned to each

source based on maximum reported earthquake in the

past and the proximity to each seismic source. Also, it

is very important to determine the focal depth of

earthquake in the region. Considering the distribution

of epicenters, focal depth of 10 km is adopted as

shown in Fig. 4. The attenuation relationship devel-

oped by IYENGAR and RAGHUKANTH (2004) is

considered for the analysis.

6. Regional Recurrence

Usually, the seismic activity of the region is

characterized by recurrence relationships. Various

recurrence relationships are reported in the literature

(GUTENBERG and RICHTER, 1944; MERZ and CORNELL,

1973; SHAH et al. 1975). In the present investigations,

Table 1

Estimation of peak ground acceleration: deterministic approach

Major faults/lineaments Notation Length

(km)

Epicentral

distance (km)

Hypocentral distance

(h = 10 km), R (km)

Max. magnitude

(Mw)

PGA (g)

Kutch Mainland Fault (KMF) F1 140 339.00 339.15 7.7 0.008

Island Belt Fault (IBF) F2 130 350.00 350.14 5.6 0.001

Cambay West Fault (CWF) F3 200 120.00 120.42 5.7 0.016

North Katiawar Fault (NKP) F4 135 343.00 343.15 5.7 0.001

Son Narmada Fault (SNF) F5 550 42.42 43.58 6.3 0.128

Tapi North Fault (TNF) F6 395 6.43 11.89 5.0 0.158

Barwani Sukta Fault (BSF) F7 180 220.00 220.23 6.3 0.008

Upper Godawari Fault (UGF) F8 240 110.00 110.45 4.3 0.004

West Coast Fault (WCF) F9 308 35.47 36.85 5.7 0.090

Chiplun Fault (CF) F10 105 251.00 251.20 4.2 0.001

Kim Fault (KF) F11 180 123.00 123.41 5.0 0.007

Cambay East Fault (ECF) F12 290 105.00 105.48 5.7 0.020

Lathi-Rajkot Lineament L1 205 295.00 295.17 5.7 0.002

Chambal-Jamnagar Lineament L2 175 300.00 300.17 5.8 0.002

Kishangarh-Chipri Lineament L3 210 169.00 169.30 4.6 0.003

Rakhabodev Lineament L5 325 213.00 213.23 5.2 0.003

Bold values represent faults considered for the probabilistic analysis


a simple and widely used GUTENBERG and RICHTER

(1944) relationship has been adopted to evaluate the

seismic hazard parameter b.

log10 N a bM 1where, N stands for the cumulative number of

earthquakes greater than or equal to a particular

magnitude M per year, parameters a and b describe

the seismic activity of the region. The simplest way

to obtain a and b is through least square regression,

but due to incompleteness of the database, such an

approach leads to erroneous results. Historical

earthquake records are usually more complete for

larger earthquakes than for smaller ones. Small

earthquakes can go undetected for a variety of

physical and demographical reasons. Fitting a straight

line, such as that implied by the G-R law, through

recurrence data, in which the mean rate of exceed-

ance of small earthquakes is underestimated, will

tend to flatten the line. As a result, the actual mean

rate of small earthquakes will be underestimated and

the mean rate of large earthquakes will be overesti-

mated (MENON et al. 2010). Two different methods,

namely, the visual cumulative (CUVI) method (TINTI

and MULARGIA, 1985) and the method by STEPP (1973)

were used to calculate the completeness periods for

different magnitude classes as shown in Fig. 5 and

Fig. 6. Table 2 summarizes completeness periods

estimated with these two methods. Recently, the

study by EPRI (2006) indicates that the parameter a

and b are sensitive to the selection of the threshold

magnitude (m0). In the present study m0 has been

found from the frequency magnitude distribution, as

the value from where the data depart from a straight

line as suggested by WIEMER and Wyss (2000). In

addition, the effects of very small earthquakes are of

little interest as they are not capable of causing sig-

nificant damage and hence earthquakes above,

m0 = 4.0 is set as threshold value for the present

analysis.

The completeness periods from both the analyses

(Table 2) have been used to compute the G-R mag-

nitude-frequency relationship as shown in Fig. 7. The

recurrence relations obtained from both the methods

is,

LogN 0:87Mw 3:8; R2 0:985 From Stepp 1973 method 2a

LogN 0:91Mw 4:0; R2 0:985 From CUVI method 2b

However, comparison of both the methods from

Table 2 and Fig. 7 suggests that the results are in

good agreement; hence, the average value has been

adopted in the present study as given below.

LogN 0:89 0:02Mw 3:9 0:1 2From Figs. 2, 8 and Table 2 it can be concluded

that the catalogue for the period since 1958 is com-

plete from magnitude 3.0 as better recording of data

has been observed in the last 50 years. Hence, the

whole catalogue from 18182008 has been divided in

two parts; 18181958 historical data (as the extreme

part of catalogue) and from 19582008 instrumental

Figure 4Latitude and longitude with depth of earthquake occurrences


(b)

(a)

(c)

(d)

(e)

(f)

(g)

(h)

Figure 5CUVI method


data (complete part of catalogue) as shown in Fig. 8.

It has been noted that the effect of Bhuj (2001) and

Kutch (1819) earthquakes are also considered in the

analysis as the Bhuj (2001) event produced signifi-

cant damages in the Surat and surrounding areas

although the epicenter of this earthquake is just

outside the limit of 350 km radius around the city.

The b value obtained in this study matches well

with the previous studies RAO and RAO (1984), SEE-

BER et al. (1999), RAGHUKANTH and IYENGAR (2006),

JAISWAL and SINHA (2006), ANBAZHAGAN et al. (2008)

and VIPIN et al. (2009) in PI. However, LAI et al.

(2009) and MENON et al. (2010) reported higher b

values for Kancheepuram and Tamil Nadu respec-

tively, this may imply that the study area is prone to

higher magnitude earthquakes in comparison to these

regions of Tamil Nadu. Table 3 presents the b

values published by different authors for PI along

with the values obtained in the present study.

7. Deaggregation and Selection of Sources

for Probabilistic Hazard Analysis

From the deterministic seismic hazard analysis

carried out on 16 sources in the study area (Table 1),

five sources gave PGA above 0.01 g, have been

selected for the probabilistic seismic hazard estima-

tion. These sources are namely Cambay East Fault

(CEF), Son Narmada Fault (SNF), Tapi North Fault

(TNF), West Coast Fault (WCF) and West Cambay

Fault (CWF). The detail of five sources with reported

numbers of earthquake data close to each source are

shown in Table 4. In Table 4, the shortest and longest

Figure 6Stepp method

Table 2

Completeness period for different magnitude classes

CUVI method STEPP (1973) method

Magnitude class

(Mw)

Completeness

period

Completeness

interval (years)

Magnitude

class (Mw)

Completeness

period

Completeness

interval (years)

3.03.4 19582008 50 3.03.4 19582008 50

3.53.9 19582008 50 3.53.9 19582008 50

4.04.4 19582008 50 4.04.4 19582008 50

4.54.9 19522008 56 4.54.9 19482008 60

5.05.4 19382008 70 5.05.4 19382008 70

5.55.9 19032008 105 5.55.9 19082008 100

6.06.4 18452008 163 C6.0 18382008 170

C6.5 18182008 190 *** *** ***

Figure 7Regional frequency-magnitude relationships


distances from the point of interest (Surat city) are

presented.

The recurrence relation in Eq. 2 derived in the

present study is for the entire region and not nec-

essarily applicable to any particular fault. Fault level

recurrence is necessary to differentiate activity rates

among the seismic sources. The most reliable way is

to plot a frequency magnitude relation for individual

sources. Because of the paucity of sufficient number

of earthquake data around the individual sources, it

is very difficult to compute reliable seismic param-

eters and, therefore, this approach may lead to

erroneous results. An alternative is to empirically fix

the b value by measuring the slip rate of a fault.

For the faults under consideration, no slip values are

available. Moreover, PI earthquakes are associated

with poor surface expressions of faults and hence

reliable estimation of slip rates has not yet been

possible (RAJENDRAN and RAJENDRAN, 1999; IYENGAR

and RAGHUKANTH, 2004), hence an approach given

by RAGHUKANTH and IYENGAR (2006) based on heu-

ristic basis invoking the principle of conservation of

seismic activity is adopted, This method has also

been followed by IYENGAR and GHOSH (2004), RAG-

HUKANTH and IYENGAR (2006), ANBAZHAGAN et al.

(2008) and VIPIN et al. (2009) for PSHA of Delhi,

Mumbai, Bangalore and PI respectively. According

to RAGHUKANTH and IYENGAR (2006), the regional

seismicity measured in terms of the number of

earthquakes per year with m C m0, should be equal

to the sum of such events occurring on individual

faults.

Hence; Nm0 X

Nim0i 1; 2. . .; 5 3

However, in finding Ni(m0), some assumptions are

necessary. First, a longer fault can produce more

small events of magnitude m0 than a shorter fault.

Hence, Ni (m0) may be taken as being proportional to

the length of the fault, leading to a simple weight

factor for source i,

ai LiPLi

4

where Li is the length of the fault i.

On the other hand, one may also consider that

future activity will continue, at least in the short run,

similar to past activity. Hence, irrespective of its

length, the seismic activity should relate to the

number of past events associated with it in the cata-

logue. This way one can arrive another weight factor

vi as;

vi NiNR

5

where Ni = number of earthquakes close to the

source and NR = total number of earthquakes in the

region.

The recurrence relation for source i is obtained by

averaging both weighting factor and multiplying the

regional relation as given below;

Figure 8Distribution of earthquake magnitude with years

Table 3

Comparison of b values with values reported in the literature

for PI

Author b Value Region

RAM and RATHOR (1970) 0.81 PI

KAILA et al. (1972) 0.70 PI

RAO and RAO (1984) 0.85 PI

SEEBER et al. (1999) 0.89 Maharashtra State

RAGHUKANTH and

IYENGAR (2006)

0.86 Mumbai city

JAISWAL and SINHA (2006) 0.91 PI

ANBAZHAGAN et al. (2008) 0.87 0.03 Bangalore city

VIPIN et al. (2009) 0.891 0.07 PI

LAI et al. (2009) 1.26 Kancheepuram,

Tamil Nadu

MENON et al. (2010) 1.13 Tamil Nadu

Present analysis 0.89 0.02 Surat city


m Nim0 0:5ai viNm0 6The weighting factors calculated for each source

are shown in Table 5. The maximum magnitude

(mmax) for each source was estimated based on the

maximum reported magnitude at the source plus 0.5

(KIJKO and GRAHAM, 1998; RAGHUKANTH and IYENGAR,

2006; ANBAZHAGAN et al. 2008). The recurrence

relation for each fault capable of producing earth-

quake magnitude in the range of m0 to mmax was

calculated using the truncated exponential recurrence

model developed by MCGUIRE and ARABASZ (1990)

and an annual rate of event of magnitude CMw (km)is given by following expression;

km m expbm mo expbmmax mo1 expbmmax mo

7for mo B m B mmax

where, mo is the threshold magnitude, b = 2.303b and Ni (m0) or m is the weightage factor for a par-ticular source based on deaggregation. The

deaggregation of regional hazard in terms of fault

recurrence is shown in Fig. 9. Finally probability

density function fM(m) is calculated for each fault

based on the following expression.

fMm PM\m=m0 mmmax b expbm mo

1 expbmmax mo 8

8. Predictive Relationship

Magnitude, distance and site conditions are the

principal variables used in predicting future ground

motions. A large number of predictive relationships

derived from regression analysis of strong motion

Table 4

Vulnerable sources considered for probabilistic seismic hazard analysis

Faults/lineaments Notation Magnitude

(Mw)

Shortest hypocentral

distance (km)

Longest hypocentral

distance (km)

No. of earthquakes

close to the source

Cambay East Fault (ECF) F12 5.7 108.67 340.66 08

Son Narmada Fault (SNF) F5 6.3 43.58 393.67 23

Tapi North Fault (TNF) F6 5.0 11.89 370.85 19

West Coast Fault (WCF) F9 5.7 36.86 348.05 22

Cambay West Fault (CWF) F3 5.7 139.65 334.28 24

Table 5

Source recurrence relation weighing factors

Faults/

lineaments

Surat

city

Magnitude

(Mw)

Length

(Lf)

No. of earthquakes

close to the source

ai vi Average weighingfactor

ECF F12 5.7 290 8 0.166 0.026 0.096

SNF F5 6.3 550 23 0.316 0.076 0.196

TNF F6 5.0 395 19 0.227 0.063 0.145

WCF F9 5.7 308 22 0.177 0.073 0.125

CWF F3 5.7 200 24 0.115 0.079 0.097

Figure 9Deaggregation of regional hazard in terms of fault recurrence


data are available for peak ground acceleration. Since

the study area is located in PI, the attenuation relation

developed by IYENGAR and RAGHUKANTH (2004)

through a statistically simulated seismological model

for rock a site is used for this study. The attenuation

relation suggested for the study area is given in Eq. 9.

ln Y C1 C2M 6 C3M 62 ln R C4R ln e

9where Y, M, R and e refer to the PGA/Spectralacceleration (g) at the bedrock level, Moment mag-

nitude, hypocentral distance, and error associated

with the regression respectively. The coefficients C1,

C2, C3 and C4, derived for the western-central region

of India by IYENGAR and RAGHUKANTH (2004) is con-

sidered for the hazard analysis. These coefficients in

Eq. 9 have been obtained from the extensive seis-

mological modeling and simulation by RAGHUKANTH

and IYENGAR (2007). This relation is valid for bedrock

sites with a shear wave velocity of 3.6 km/s. The

normal cumulative function has a value which is

more efficient in terms of the standard normal vari-

ables (z) which can be computed for any random

variable using a transformation as given below;

z ln Y ln Y

rln e 10

Where Y* is the various targeted PGA/Sa levels

which will be exceeded, ln Y is the value calculated

using predictive relationship and ln e is the uncer-tainty in the predictive relation expressed by the

standard deviation.

PETERSEN et al. (2004) compared Kutch ground

motion data from the 2001 Bhuj earthquake for sites

located 230 km and 950 km from hypocenter in Ah-

madabad and Delhi respectively (University of

Roorkee, CRAMER and WHEELER, 2001) with published

ground motion equations. This comparison suggests

that the crustal intraplate relation of FRANKEL et al.

(1996) yields ground motion similar to the strong

ground motion data recorded from 2001 Bhuj earth-

quake at large distances. A comparison of various

attenuation relationships have been made by JAISWAL

and SINHA (2007), and they gave 50% weightage to the

relationship developed by IYENGAR and RAGHUKANTH

(2004) and rest to other attenuation relationships.

9. Local Site Effects

Considerable variation in the ground motion is

observed due to local site conditions, and hence, sur-

face level spectral acceleration values can be different

from bed rock values. Several approaches were used

to include site effect into PSHA (e.g. SUZUKU and

KIREMIDJAN, 1998; BERNREUTER et al. 1986; TOKI et al.

1991; BORCHERDT, 1994; MARITINI et al. 1994; ERDIK,

1995; etc.) most of them use site coefficients which

modify the basic PGA, spectral shape or intensity based

on the site classification, depending on the geotechnical

properties like shear wave velocity (BORCHERDT, 1994)

or geological condition (TOKI et al., 1991). The widely

adopted method for classifying a site is the average

shear wave velocity in the top 30 m of the site com-

monly known as Vs30. This parameter has been adopted

by many building codes for classifying a site for the

purpose of incorporating local site conditions in the

estimation of the design ground motion. The results of

Eq. 9 are modified for local site condition (RAGHUKANTH

and IYENGAR, 2007) used for the present analysis.

ys YFs 11and; ln Fs a1Y a2 ln ds 12

where Fs is amplification coefficient, ys is spectral

acceleration at the ground surface for a given site

class, a1 and a2 are regression coefficients and ds isthe error term corresponding to site classification,

s = A, B, C, D. These coefficients along with the

standard deviation of error r(ln ds) as reported byRAGHUKANTH and IYENGAR (2007) are considered for

the analysis. The variation from the mean is charac-

terized by standard deviation expressed as:

rln es rln e2 rln ds2

q13

10. Probabilistic Seismic Hazard Analysis

Probabilistic seismic hazard analysis (PSHA) was

initially developed by CORNELL (1968) and incorpo-

rates the influence of all potential sources of

earthquakes and the activity rate assigned to them.

Thereafter, many researchers have adopted this meth-

odology for evaluating hazard and recently this method


has been adopted by IYENGAR and GHOSH (2004),

RAGHUKANTH and IYENGAR (2006), ANBAZHAGAN et al.

(2008), and VIPIN et al. (2009) for the probabilistic

seismic hazard analysis of Delhi, Mumbai, Bangalore

and PI respectively. The procedure for carrying out

PSHA has been demonstrated by KRAMER (1996) and is

adopted for the present analysis. A common approach

involves the development of seismic hazard curves,

which indicates the annual probability of exceedance

of different values of a selected ground motion

parameter. The seismic hazard curves can be used to

compute the probability of exceeding the selected

ground motion parameter in a specified period of time.

Seismic hazard curves can be obtained for individual

source zones and are combined to express aggregate

hazards at a particular site. For a given earthquake

occurrence, the probability that a ground motion

parameter Y will exceed a particular value y* can be

computed using total probability theorem; that is:

P Y [ y P Y [ y=X P X Z

P Y [ y=X fxXdx 14

where X is a vector of random variables that influ-

ences Y. In most cases, the quantities in X are limited

to magnitude M, and distance R. Assuming that M

and R are independent, the probability of exceedance

can be written as:

PY [ y ZZ

PY [ y=m; rfMmfRrdmdr15

where P[Y [ y*/m,r] is obtained from the predictiverelationship and fM(m) and fR(r) are the probability

density functions for magnitude and distance,

respectively. If the site of interest is a region of Ns

potential earthquake sources, each of which has an

average rate of threshold magnitude exceedances,

m expai bimo; the total average exceedancerate the region will be given by

ky XNs

i1mi

ZZPY [ y=m; rfMimfRirdmdr

16The individual components of Eq. 16 are, quite

complicated that the integrals cannot be evaluated

analytically. Numerical integration, which can be

performed by a variety of different techniques, is

therefore required. One approach used for simplicity

to divide the possible ranges of magnitude and dis-

tance into NM and NR segments respectively. The

average exceedance rate can be estimated by,

ky XNs

i1

XNM

j1

XNR

k1miPY [y=mj;rkfMimjfRirkDmDr

17where mj = mo ? (j - 0.5)(mmax - mo)/NM, rk =

rmin ? (k - 0.5)(rmax - rmin)/NR, Dm = (mmax -mo)/Nm and Dr = (rmax - rmin)/NR. This is equiva-lent to assuming that each source is capable of

generating only NM different earthquakes of different

magnitude mj, at only NR different source to site

distances, rk, and hence, Eq. 17 equivalent to,

ky XNs

i1

XNM

j1

XNR

k1miPY [y=mj;rkPMmjPR rk

18Assuming that the number of earthquakes occur-

ring on a fault follows a stationary Poissons process,

the probability that the control variable Y exceeds

level y*, in terms of a finite time interval T years is

given by:

PYT [ y 1 exp ky T 19

Figure 10Seismic hazard at rock level for Surat, Gujarat, India


The seismic hazard curves can be obtained by

computing the mean annual rate of exceedance ky, fordifferent specified ground motion values y*. These

curves are first obtained individually for all the five

faults and combined to estimate the aggregate hazard

at the site. The seismic hazard curve for PGA at bed

rock obtained by the above method is shown in Fig. 10

along with the individual contribution from all five

faults. It is observed that the seismic hazard at Surat is

mainly contributed by three faults namely, Tapi North

Fault (TNF), Son Narmada Fault (SNF) and West

Coast Fault (WCF). The site condition in Surat city

may vary A-type to F-type based on the NEHRP

classification. Ideally, with the help of detailed shear

wave velocity profiles, covering all parts of city, pre-

cise estimation of site specific hazard will be possible.

Even in absence of this, the design response spectrum

can be standardized for the sites of A, B, C, and D.

Seismic hazard curves for PGA computed separately

for these sites in Surat is shown in Fig. 11, for E- and

F-type sites, rigorous nonlinear site response analysis

would be needed, with specific parameters and is

outside the scope of the present study.

11. Uniform Hazard Response Spectrum

The current approach in engineering practice is to

use design response spectra with equal probability of

exceedance over the entire frequency range of inter-

est. Such design spectra are known as Uniform

Hazard Response Spectra (UHRS). In the present

study, uniform hazard response spectra is developed

from probabilistic ground motion analysis that has

equal probability being exceeded at each period of

vibration. For finding UHRS, seismic hazard curves,

response spectra at specified probability of exceed-

ance over the entire frequency range of interest are

evaluated using Eq. 9 and site coefficients suggested

by RAGHUKANTH and IYENGAR, 2007. The International

Code IBC (2000) prescribed design forces based on

spectral acceleration (Sa) corresponding to 10 and 2%

probability of exceedance in 50 years. These corre-

spond to 475 and 2,475 years return periods

respectively. Figure 12 shows the UHRS (with

damping of 5%) at bed rock level for Surat city

corresponding to the above two standard return

periods. Spectral acceleration (Sa) corresponding to

1 s natural period, is known as long period seismic

period. It is observed that, for the same return period,

spectral acceleration is high on soft soil sites.

Figure 13 shows the hazard curves corresponding to

1 s natural period for different site classes (A, B, C and

D). Uniform hazard response spectrum (with damping

of 5%) for different site in Surat city according to

NEHRP site classification for 10 and 2% probability of

exceedance in 50 years presented in Fig. 14.

12. Results and Discussions

In the present study, the seismic hazard analysis is

carried out for the establishment of PGA at bed rock

Figure 11Effect of local site condition on seismic hazard in Surat, Gujarat

Figure 12UHRS (with damping of 5%) at bed rock level for Surat city

corresponds to 10 and 2% of probability of exceedance in 50 years


level for Surat city based on the deterministic

approach. An attempt has also been made to evaluate

the seismic hazard in terms of PGA and Sa at rock

level and PGA at ground level, based on different site

classes for Surat city based on probabilistic hazard

analysis. The seismic hazard curves and UHRS for 2

and 10% probability of exceedance in 50 years are

calculated using newly developed Microsoft Excel

program. There are no previous engineering studies

in open literature on probabilistic seismic hazard

analysis covering Surat region. Hence, the results of

the present study are compared with the studies

reported in the literature on PI (SEEBER et al. 1999;

IYENGAR and RAGHUKANTH, 2004; ANBAZHAGAN et al.

2008; BOOMINATHAN et al. 2008; JAISWAL and SINHA,

2008, VIPIN et al. 2009). The results are also com-

pared with the Indian Standard Code (BIS 1893:

2002).

Site A Site B

Site C Site D

Bedrock

Figure 13Hazard curves for 1 s for different sites (Class A, B, C, D, and bedrock)


As stated earlier, b value obtained in the present

study matches well with the most studies reported in

the literature for PI.

In the present investigation, the peak ground

accelerations (PGA) 0.100 and 0.138 g are obtained

for 10 and 2% probability of exceedance in 50 years,

respectively. As the time unit is not taken into

consideration in the deterministic approach, the

probabilistic and deterministic values should not

compare. However, in the present study, they have

been compared considering NEHRP (BSSC 2001)

clause 4.1.3.1. According to this, when site specific

procedure are utilized, maximum considered earth-

quake ground motion shall be taken as that motion

represented by a 5% damped acceleration response

spectrum having a 2% probability of exceedance in a

50 years. Deterministic approach is also considered

for maximum credible earthquake. Hence considering

the MCE is likened to ground motion with 2475 yr

return period, while the DBE is likened to the 475 yr

return period (MENON et al., 2010), the deterministic

results are compared with 2% probability of

exceedance in 50 years (2,475 R.P.) results. The

value of PGA at 2% of probability of exceedance in

50 years is comparable with PGA value of 0.158 g

obtained from deterministic analysis. The study

illustrates that the probabilistic and deterministic

approaches may lead to comparable answers and

complementing each other and provides additional

insights to the seismic hazard assessment.

The PGA value for 10% probability of exceed-

ance in 50 years for Surat city, considering different

sites varies from 0.100 to 0.210 g, with a maximum

value of 0.210 for Site D (BSSC, 2001). However,

these PGA values at bedrock obtained from the cur-

rent investigation are comparable with GSHAP maps

of BHATIA et al. (1999) for the same region. However,

BHATIA et al. (1999) have not given any information

regarding the influence of local Soil.

In recent years, the building codes are revised to

consider the 2% probability of exceedance in

50 years (VIPIN et al., 2009) which corresponds to a

return period of 2,475 years. Peak ground accelera-

tion value for the above return period varies from

0.138 to 0.335 g considering the various site condi-

tion (BSSC, 2001) with maximum value of 0.335 g

for Site D. The PGA value of 0.335 g corresponds to

zone V as per the current seismic hazard map of India

(BIS 1893:2002). Similarly for return period of

475 years the maximum PGA value of 0.210 g is

obtained for Site D, which corresponds to zone IV

as per the current seismic hazard map of India.

However, Surat region is placed in the zone III cor-

responds to maximum PGA value of 0.16 g.

Uniform hazard response spectra (UHRS) with 10

and 2% probability of exceedance in 50 years were

developed for bedrock and A, B, C and D type soil

classes (BSSC, 2001) for Surat city (Fig. 14). The

results of these curves show the variation of pre-

dominant frequency with change in soil types. The

period of oscillation corresponding to maximum

spectral acceleration varies from 0.04 s at bedrock

level to 0.1 s at ground surface for site class D which

shows low rise buildings are most vulnerable to

earthquake damage. VIPIN et al. (2009) and RAGHUK-

ANTH and IYENGAR (2004) found that the period of

oscillation for Bangalore and Mumbai city respec-

tively in PI, the values ranges from 0.05 s for bedrock

(a)

(b)

`

Figure 14Uniform hazard response spectrum for different sites according to

NEHRP classifications a 10% probability of exceedance in 50 years

b 2% probability of exceedance in 50 years


to 0.2 s for site class D. The results of present

investigations are compared with various studies in

the literature for PI (Table 6). The values obtained

from the present study shows some degree of simi-

larity with the studies reported in the literature.

In this article, Surat city has been represented as a

single point. This is not a major limitation in

estimating seismic hazard. Previous work on mi-

crozonation of Delhi (IYENGAR and GHOSH, 2004; RAO

and NEELIMA, 2005) shows that surface level spatial

variation of hazard, on a city size region, depends

more on local soil conditions rather than on the

disposition of seismic sources. Hence at bedrock

condition, spatial variation within city limits is

expected to be minimal. However, different sites in a

city will have different Vs30 values and belong to one

of A, B, C and D types. With this in view, in the

present study, design response spectra have been

derived for these four types of sites. Also, the current

study highlights the influence of local site effect on

the ground motion characteristics and shows the need

for the revision of the current code (IS 1893:2002) of

practice in India.

However, the above process has several limita-

tions as cited by RAGHUKANTH and IYENGAR (2006). In

addition, all the sources are assumed to be a line

source. It is important to note that for large portions

of peninsular India (i.e., the quiet zones of cratons);

the historical catalog includes no information about

the previous earthquake activity due to its relatively

short time span (JAISWAL and SINHA, 2008). It is

possible that many smaller magnitude earthquakes in

these quiet zones have not been recorded due to a

sparse instrumental network even during the last

several decades. A seismic source incorporating

background seismicity was not included in the pres-

ent study. Apart from the above limitations, this

procedure may lead to the best possible results under

the present seismic scenario as stated by RAGHUKANTH

and IYENGAR (2006).

REFERENCES

ANBAZHAGAN, P., VINOD, J.S., and SITHARAM, T. G. (2008). Proba-

bilistic seismic hazard analysis for Bangalore. Nat. Hazards. 8,

145166.

BASU, S., and NIGAM, N.C. (1977). Seismic risk analysis of Indian

Peninsula. Proc. 6th World Conf. Earthquake Engg. New Delhi.

1, 782788.

BIS-1893:2002. Indian standard criteria for earthquake resistant

design of structures, Part 1 General provisions and buildings.

Bureau of Indian Standards, New Delhi, India.

BERNREUTER, D.L., CHEN, J.C., and SAVY, J.B. (1986). A method-

ology to correct for the effect of the local site characteristics in

seismic hazard analyses. Proc. 3rd U.S. National Conf. on

Earthquake Engineering California, 245255.

BHATIA, S.C., KUMAR, M.R., and GUPTA, H.K. (1999). A probabi-

listic seismic hazard map of India and adjoining regions. Annali

di geofisica, 42(6):11531164.

BOOMINATHAN, A., DODAGOUDAR, G.R., SUGANTHI, A. and MAHES-

WARI R.U., (2008), Seismic hazard assessment of Chennai city

considering local site effects, J. Earth Syst. Sci. 117, S2,

853863.

BORCHERDT, R.D. (1994). Estimates of site dependent response

spectra for design (methodology and justification). Earthq.

Spectra. 10(4), 617653.

BSSC:2001 NEHRP recommended provision for seismic regula-

tions for new buildings and other structure 2000 edition, part 1:

Provision Report no. FEMA 368, Building seismic safety council

for the federal emergency management agency, Washington, DC,

USA.

Table 6

Comparison of ground motion parameters reported in literature

Ground motion parameters Value Region Author

PGA (475 R.P.) in g 0.100 Surat city Present study

0.090 Mumbai city RAGHUKANTH and IYENGAR (2006)

0.121 Bangalore ANBAZHAGAN et al. (2008)

PGA (2475 R.P.) in g 0.138 Surat city Present study


0.151 Bangalore ANBAZHAGAN et al. (2008)

Sa (0.01 s and 475 R.P) in g 0.210 Surat city Present study


Sa (0.01 s and 2475 R.P) in g 0.310 Surat city Present study


R.P. return period


CHANDRA, U. (1977). Earthquakes of PI- A seismotectonic study

Bull. Seismol. Soc. Am. 67(5), 13871413.

CORNELL, C.A. (1968). Engineering seismic risk analysis. Bull.

Seismol. Soc. Am. 58, 15831606.

CRAMER, C.H. and WHEELER, R.L. (2001), The 2001 Gujarat, India

earthquake and seismic hazard in central and Eastern North

America. Abstract in Seismological Letters, 72, 396.

EPRI (2006). Program on technology innovation: Truncation of the

lognormal distribution and value of the standard deviation for

ground motion models in the Central and Eastern United States,

MD: 2006.1014381, Department of Energy, Germantown, Palo

Alto, CA.

ERDIK, M. (1995) Developments on empirical assessment of the

effect of surface geology on strong ground motion. In Proc. 10th

European Conf. on Earthquake Engineering, 25932598.

FRANKEL, A., MUELLER, C. BARNHARD, T. PERKINS, D., LEYENDECKER,

E.V., DICKMAN, N., HANSON, S., and HOPPER, M. (1996). National

Seismic Hazard Maps, Open File Report (USGS) 96-552, 41.

Available at http://eqhazmaps.usgs.gov/hazmapsdoc/junedoc.

pdf.

GUBIN, I. E. (1968). Seismic zoning of Indian Peninsula Bull.

Intern. Inst. Seism. Earthq. Eng. 5, 109139.

GUHA, S.K. (1962). Seismic regionalization of India. 2nd Sym.

Earthquake Engg., Roorkee, 191207.

GUHA, S.K., and BASU, P.C. (1993). Catalogue of earthquakes

(M C 3.0) in Peninsular India, Atomic Energy Regulatory

Board, Tech. Document No. TD/CSE-1, 170.

GUTENBERG, B. and RICHTER, C. F. (1944). Frequency of earth-

quakes in California. Bull. Seismol. Soc. Am. 34, 185188.

GUTENBERG, B. and RICHTER, C.F. (1956). Earthquake magnitude,

intensity, energy and acceleration. Bull. Seismol. Soc. Am. 46,

105145.

HEATON, T.H., TAJIMA, F., and MORI, A.W. (1986). Estimating

ground motions using recorded Accelerograms. Surv. Geophys.

8(1), 2583.

IBC (2000): International Code Council, International Building

Code, Falls Church, VA.

IYENGAR, R.N. and RAGHUKANTH, S.T.G. (2004). Attenuation of

strong ground motion in Peninsular India Seismol. Res. Lett. 75,

530540.

IYENGAR, R.N. and GHOSH, S. (2004). Microzonation of earthquake

hazard in greater Delhi area Curr. Sci. 87, 11931202.

JAISWAL, K., and SINHA, R. (2005). EarthquakeInfo.org: Webportal

on earthquake disaster awareness in India. http://www.

earthquakeinfo.org. Last Accessed May 2009.

JAISWAL, K., and SINHA, R. (2006). Probabilistic modeling of

earthquake hazard in stable continental shield of the Indian

Peninsula. ISET J. Earthq. Technol. 43(3), 4964.

JAISWAL, K. and SINHA, R. (2007). Probabilistic seismic-hazard

estimation for Peninsular India. Bull. Seismol. Soc. Am. 97(1B),

318330.

JAISWAL, K., and SINHA, R. (2008), Spatial-temporal variability of

seismic hazard in Peninsular India. J. Earth Syst. Sci. 117, S2,

707718.

KANAMORI, H. (1983). Magnitude scale and quantification of

earthquakes. Tectonophysics. 93, 185199.

KAILA, K.L., GAUR, V.K., and NARAIN, H. (1972). Quantitative

seismicity maps of India. Bull. Seismol. Soc. Am. 62,

11191131.

KAILA, K.L., and RAO, N.M. (1979). Seismic zoning maps of the

Indian subcontinent. Geophys. Res. Bull. 17, 293301.

KHATRI, K.N., ROGERS, A.M., and ALGERMISSEN, S.T. (1984). A

seismic hazard map of India and adjacent areas Tectonophysics,

108, 93134.

KHATTRI, K.N. (1992). Seismic hazard in Indian region. Curr. Sci.

62 (1-2), 109116.

KIJKO, A., and GRAHAM, G. (1998). Parametric-historic procedure

for probabilistic seismic hazard analysis, Part I: Estimation of

maximum regional magnitude Mmax. Pure Appl. Geophy. 152,

413442.

KRAMER, S.L. (1996). Geotechnical earthquake engineering, Pre-

ntice-Hall International Series in Civil Engineering and

Engineering Mechanics, Washington, 106129.

KRINITZSKY, E.L. (2002). How to obtain earthquake ground motions

for engineering design. Eng. Geol. , 116.

KRISHNA, J. (1959). Seismic zoning of India. In Earthquake Engg.,

Seminar, Roorkee University, India, 3238.

LAI, C.G., MENON, A., CORIGLIANO, M., ORNTHAMARRATH, T.,

SANCHEZ, H.L., and DODAGOUDAR, G.R. (2009). Probabilistic

seismic hazard assessment and stochastic site response analysis

at the archaeological site of Kancheepuram in southern India.

Research Report EUCENTRE 2009/01, IUSS Press, Pavia, isbn

978-88-6198-037-2, 250.

MALIK, J.N., SOHONI, P.S., KARANTH, R.V., MERH, S.S. (1999).

Modern and historic seismicity of Kachchh Peninsula, western

India. J. Geol. Soc. India 54, 545550.

MANDAL, P., RASTOGI, B.K., and GUPTA, H.K. (2000). Recent Indian

earthquakes. Cur. Sci. 79(9), 13341346.

MARITINI, G., ROMEO, R., SABETTA, F., SODDI, P., DAMINELLI, R.,

MARCELLINI, A., MIRENNA, S., PAGANI, M., RIVA., F. and MANELLI,

G. (1994). SMCP-Seismic microzoning computer program, In

Proc. XXIV General Assemby of ESC, Unversity of Athens,

Greece, 16191627.

MCGUIRE, R.K., and ARABASZ, W.J. (1990). An Introduction to

probabilistic seismic hazard analysis, Geotechnical and Envi-

ronmental Geophysics, ed. by Ward, S.H. Society of Exploration

Geophysicist, 1, 333353.

MENON, A., ORNTHAMMARATH, T., CORIGLIANO, M., and LAI, C.G.

(2010). Probabilistic seismic hazard macrozonation of Tamil

Nadu in Southern India. Bull. Seismol. Soc. Am. 100(3),

13201341.

MERZ, H.A., and CORNELL, C.A. (1973). Aftershocks in engineering

seismic risk analysis. Report, Department of Civil Engineering,

Massachusetts Institute of Technology, Cambridge, Massachu-

setts, 73125.

OLDHAM, T.A. (1883). Catalogue of Indian earthquakes. Mem.

Geol. Surv. India, 19, 163215.

PETERSEN, M.D., RASTOGI, B.K., SCHWEIG, E.S., HARMSEN, S., and

GOMBERG, J.S. (2004). Sensitivity analysis of seismic hazard for

the northwestern portion of the state of Gujarat, India. Tec-

tonophysics, 390, 105115.

RAGHUKANTH, S.T.G., and IYENGAR, R.N. (2006). Seismic hazard

estimation for Mumbai city Curr. Sci. 91(11), 14861494.

RAGHUKANTH, S.T.G., and IYENGAR, R.N. (2007). Estimation of

seismic spectral acceleration in Peninsular India J. Earth Sys.

Sci. 116(3), 199214.

RAJENDRAN, K., RAJENDRAN, C.P. (1999). Seismogenesis in the sta-

ble continental interiors: an appraisal based on two examples

from India. Tectonophysics. 305, 355370.

RAM, A., and RATHOR, H.S. (1970). On frequency magnitude and

energy of significant Indian earthquakes Pure Appl. Geophys. 79,

2632.


RAO, K.S., and NEELIMA, S. (2005), Seismic microzonation studies

for Delhi region. Symposium on Seismic Hazard Analysis and

Microzonation, September 2324, Roorkee, 213234.

RAO, R.B. (2000). Historical Seismicity and deformation rates in

the Indian Peninsular Shield. J. Seismol. 4, 247258.

RAO, R.B., and RAO, S.P. (1984). Historical Seismicity of Penin-

sular India. Bull. Seismol. Soc. Am. 74, 25192533.

Regulatory Guide 1.167 (1997). Identification and characterization

of seismic sources and determination of safe shutdown earth-

quake ground motion. US Nuclear Regulatory Commission.

SEEBER, L., ARMBRUSTER, J.G., and JACOB, K H. (1999). Probabilistic

assessment of seismic hazard for Maharashtra, Govt. of Maha-

rashtra, Unpublished Report.

SHAH, H.C., MORGAT, C.P., KIREMIDJIAN, A.S., and ZSUTTY, T.C.

(1975). Study of seismic risk for Nicaragua, Part I, Report II, The

John a Blum Earthquake Engineering Centre, Stanford, California.

SEISAT (2000). Seismotectonic Atlas of India, Geological Survey

of India.

SITHARAM, T.G., and ANBAZHAGAN, P. (2007). Seismic hazard

analysis for the Bangalore region. Nat. Hazards. 40, 261278.

STEPP, J.C. (1973). Analysis of completeness of the earthquake

sample in the Puget Sound area, ed. by in Seismic Zoning,

Harding S.T. NOAA Tech. Report ERL 267-ESL30, Boulder,

Colorado.

SUZUKU, S., and KIREMIDJAN, A.S. (1998). Consideration of soil

parameters uncertainties in the time dependent seismic hazard

models. In Struct. and Strchast. Methods (Developments in

Geotechnical Engineering), Amsterdam, 45, 427438.

TANDON, A.N. (1956). Zoning of India liable to earthquake damage.

Indian J. Meteorol. Geophys. 10, 137146.

TINTI, S., and MULARGIA, F. (1985). Completeness analysis of a

seismic catalog Ann. Geophys. 3, 407414.

TOKI, K., SATO, T. and KIYONO, J. (1991). Estimation of peak

acceleration for seismic microzonation taking into account the

fault extent. In Proc. 4th International Conf. Seismic Zonation,

Stanford, California, 731738.

VIPIN, K.S., ANBAZHAGAN, P. and SITHARAM, T.G. (2009). Estimation

of peak ground acceleration and spectral acceleration for South

India. Nat. Hazards Earth Syst. Sci. 9, 865878.

WIEMER, S., and WYSS, M. (2000). Minimum magnitude of complete

reporting in earthquake catalogs: Examples from Alaska, the

Western United States, and Japan. Bull. Seismol. Soc. Am. 90,

859869.

(Received April 11, 2010, revised February 4, 2011, accepted March 3, 2011, Published online June 9, 2011)


Use of Seismotectonic Information for the Seismic Hazard Analysis for Surat City, Gujarat, India: Deterministic and Probabilistic ApproachAbstractIntroductionStudy AreaSeismic Characteristics of the RegionGeneration of a Seismotectonic MapDeterministic Estimation of Peak Ground AccelerationRegional RecurrenceDeaggregation and Selection of Sources for Probabilistic Hazard AnalysisPredictive RelationshipLocal Site EffectsProbabilistic Seismic Hazard AnalysisUniform Hazard Response SpectrumResults and DiscussionsReferences

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