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An attenuation relationship based on Turkish strong motion data
and iso-acceleration map of Turkey
Resat Ulusay*, Ergun Tuncay, Harun Sonmez, Candan Gokceoglu
Hacettepe University, Department of Geological Engineering, 06532 Beytepe, Ankara, Turkey
Received 27 May 2003; accepted 13 April 2004
Available online 9 June 2004
Abstract
This paper presents an attenuation relationship of peak ground acceleration (PGA) derived from Turkish strong motion data
for rock, soil and soft soil sites and an iso-acceleration map of Turkey based on this relationship. For the purpose, among all the
three-component accessible records, 221 records from 122 earthquakes that occurred in Turkey between 1976 and November
2003 were selected. The database was compiled for earthquakes with moment magnitudes (Mw) and PGA values ranging
between 4.1 and 7.5, and 20 and 806 gal, and distances to epicenter considered in the database were between 5 and 100 km.
From the regression analysis of the data, an attenuation equation of PGA considering rock, soil and soft soil conditions was
developed. The PGA values predicted from the equation suggested in this study and those both from a few domestic equations
and some imported equations were compared. In addition, an iso-acceleration map of Turkey was constructed using thesuggested attenuation equation and considering both known active faults and epicenter locations of the earthquakes that have
occurred in Turkey.
D 2004 Elsevier B.V. All rights reserved.
Keywords: Attenuation relationship; Iso-acceleration map; Peak ground acceleration; Strong motion database; Turkey
1. Introduction
In seismic hazard analyses the quantitative descrip-
tion of the ground motions are very important. One of
the ground motion parameters commonly used in
geotechnical and structural engineering analyses is
peak ground acceleration (PGA). Therefore, estima-
tion of this parameter in a precise manner has a prime
importance in engineering design. Major initiatives to
instrument seismically active regions around theworld were undertaken in the twentieth century, and
these instruments have provided a large inventory of
recordings. Data from this inventory are used to
develop empirical strong motion attenuation relation-
ships to estimate earthquake ground motions based on
some characteristics of the earthquakes and local
geology. PGA is the simplest strong-motion parameter
and hence more than 120 attenuation equations have
been derived in the past to predict it (Douglas, 2003).
However, these equations were derived for different
0013-7952/$ - see front matterD 2004 Elsevier B.V. All rights reserved.doi:10.1016/j.enggeo.2004.04.002
* Corresponding author. Fax: +90-312-299-2034.
E-mail address: [email protected] (R. Ulusay).
www.elsevier.com/locate/enggeo
Engineering Geology 74 (2004) 265291
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earthquake regions and fault types, and interplate
versus intraplate. In addition, their data selection
criteria are different, and some of them pertain to
only a single ground type such as rock or firm soil. Asa result of their nature, differences among the esti-
mated PGA values from the existing attenuation
relationships from one region or country to another
result in a limitation in their use. Therefore, the use of
attenuation relationships derived from the records of a
region, where the predictive equations are considered,
shows an increasing tendency between the associated
engineering community.
In Turkey, the seismic hazard zonation map was
published by the Ministry of Public Works and
Settlement of Turkey (1996). Based on this map,
Turkey is divided into five subclasses of seismic zone
with PGA values of >0.4g, 0.30.4g, 0.20.3g, 0.1
0.2g and < 0.1g for zones ranging from I to V,
respectively. The current practice in Turkey is to
directly use the PGA values from the seismic codes
published by the Ministry of Public Works and
Settlement of Turkey (1998). According to the codes,
PGA values of 0.4g, 0.3g, 0.2g and 0.1g are assigned
for zones ranging from I to IV, respectively. However,
in seismic hazard modeling studies for Turkey, some
investigators (e.g. Erdik et al., 1985; Gulkan et al.,
1993; Kayabali, 2002) employed the relationshipssuggested for California, specifically by Joyner and
Boore (1981, 1988) due to some similarities between
the San Andreas Fault in USA and the North Anato-
lian Fault Zone in Turkey. The seismic zoning map of
Turkey have the same setbacks and these are outlined
by Kayabali and Akin (2002). In order to minimize
the effects of the setbacks in the present map, new
maps were constructed by Kayabali (2002) and Kaya-
bali and Akin (2002) using the probabilistic and
deterministic approaches, respectively. However,
Kayabali and Akin (2002) also indicated that theprobabilistic-based maps appear to have employed
relatively large seismic zones, and therefore, deter-
ministic-based seismic map seems to be more realis-
tic. In the construction of the deterministic based iso-
acceleration and seismic zoning maps of Turkey,
Kayabali and Akin (2002) considered only active
faults and ignored locations of the epicenters. In
addition, they compared two domestic attenuation
equations of strong ground motion for the earthquakes
of Turkey developed by Inan et al. (1996) and Aydan
et al. (1996), and some imported equations. Based on
their comparisons, they decided to use the equation
developed by Sadigh et al. (1997) as the appropriate
prediction equation for the construction of their map.However, the equation by Sadigh et al. (1997) does
not account for normal faulting, and it was a non-
sense comparison through the use of the distance to
epicenter instead of hypocentral distance when they
considered the equation, which was developed by
Aydan et al. (1996) modified by Aydan (2001) for
Turkey. The PGA values picked up from this iso-
acceleration map are for bedrock and it is necessary to
carry out site response analyses for the computation of
maximum PGA for soil sites.
Three domestic attenuation relationships of PGA
for the earthquakes of Turkey were suggested by Inan
et al. (1996), Aydan (2001), and Gulkan and Kalkan
(2002). The PGA equation developed by Inan et al.
(1996) is as follows:
log PGA 0:65M 0:9 log R 0:44 1
where M is the earthquake magnitude and R is the
distance to epicenter in kilometers. No distinction is
considered between the records obtained from the
stations founded on rock and soil sites in this atten-
uation relationship. It is also noted that type of the
magnitude employed in the equation and data selec-
tion criteria have not been mentioned in the related
literature. On the other hand, this relationship yields
unusually high values of PGA particularly in near
source areas.
The second attenuation relationship based on a
large database system, which is called TURDIVAZ
and involved recordings at stations on soil and rocky
grounds operated by ERD, KOERI and ITU for the
characteristics of acceleration waves of Turkish earth-
quakes, was developed by Aydan and published in a
report (Aydan, 1997) and in an article (Aydan et al.,1996), respectively. This attenuation relationship is
given in the following form:
amax 2:8e0:9Ms e0:025R 1 2
where amax is the maximum ground acceleration, and
Ms and R are the surface magnitude and the hypocen-
tral distance of a given earthquake, respectively. At the
beginning the number of data employed for the above
equation was 60. This function consists of two expo-
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nential functions, which fundamentally govern the
overall form of attenuation. Two criteria were selected
by its originator in developing this equation: (i) when
the magnitude is zero, there should not be any groundmotion, and (ii) it should also be capable of estimating
strong ground motions of large earthquakes of Turkey
with known accelerations. However, Aydan recog-
nized a small problem with Eq. (2), that is, the ground
acceleration will have a negative value when R goes to
infinity although it will almost no effect on the
estimated maximum ground acceleration. Therefore,
form of the equation was slightly modified in order to
satisfy the condition, that is, the maximum ground
acceleration should be nil when R goes to infinity, and
re-written in the following form (Aydan, 2001).
amax 2:8e0:9Ms 1e0:025R 3
The coefficient 2.8 appearing in Eq. (3) is considered
for soils and reduced to 0.56 for firm soils and rocky
grounds as the site condition coefficient. This attenu-
ation relationship generally simulated the records of
big earthquakes of Turkey.
The most recent attenuation relationship for Turkey
was developed by Gulkan and Kalkan (2002) by using
the same general form of the equation proposed for
shallow earthquakes in Western North America by
Boore et al. (1997). The ground motion parameter
estimation is as follows:
ln Y b1 b2M 6 b3M 62 b5ln r
bv lnVs=VA; 4
r R2cl h20:5; 5
where Yis the ground motion parameter (PGA or PSAin g), M is (moment) magnitude; Rcl is the closest
horizontal distance between the recording station and
a point on the horizontal projection of the rupture
zone on the earths surface in km; Vs is the shear wave
velocity for the station in m/s; b1, b2, b3, b5, h, bv and
VA are the parameters to be determined. Here h is a
fictitious depth and VA is a fictitious shear-wave
velocity that is determined by regression. Gulkan
and Kalkan (2002) utilized 47 horizontal components
of only main shocks of 19 earthquakes with magni-
tudes Mwz 5 occurred in Turkey between 1976 and
1999, and omitted the PGA values less than 40 gal.
Half of the data they employed was from the devas-
tating Kocaeli and Duzce earthquakes of 1999. Basedon the Kocaeli and Duzce events, Gulkan and Kalkan
(2002) compared their equations to some imported
attenuation relationships not specifically from record-
ings in Turkey, and concluded that the imported
relationships overestimate the peak and spectral ac-
celeration values for up to about 1520 km, for larger
distances the reverse holds. These investigators also
recommended that as additional strong motion
records, shear-wave velocity profiles for recording
sites and better determined distance data become
available for Turkey, their attenuation relationship
can be progressively modified and improved, and its
uncertainties reduced.
On the basis of the abovementioned information
and brief evaluation, the authors of the present paper
believe that the attenuation relationships derived in
other countries and for different tectonic regimes
should be carefully utilized for seismic assessments
in Turkey. Therefore, the authors considered that
derivation of an attenuation equation for PGA based
on a larger database as a contributory study to those
carried out to develop domestic equations for Turk-
ish earthquakes, and its use in practice may becomeuseful. In this study, an attempt was made to derive
an attenuation equation of PGA for rock, soil and
soft soil sites in Turkey. The database, employed in
this study included the records from the earthquakes
of Mwz 4 between 1976 and November 2003.
Among all the three-component records, 221 records
of 122 earthquakes were selected for regression
analysis, and effects of the site conditions were also
considered. From the regression analysis of data, the
equation to predict PGA for the sites underlain by
rock, soil and soft soil were established. The PGAvalues estimated from the equation developed in this
study and those from some previous domestic atten-
uation equations and some imported models based
on worldwide data were compared. In addition,
using the proposed attenuation equation and consid-
ering the epicenters of the earthquakes and the
known active faults of Turkey, PGA values were
calculated. Then the calculated PGA values were
contoured to obtain an iso-acceleration map of
Turkey. The PGA value picked up from the map
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for any site is for bedrock, and when it is multiplied
by the coefficients, the PGA of soil and soft soils
can be found.
2. Data selection criteria and database
Installation of the acceleration recorders was initi-
ated in Turkey in 1973 in relation with the project of
Strong Ground Motion Network of Turkey, under the
responsibility of the Earthquake Research Department
(ERD) of the General Directorate of Disaster Affairs
(GDDA). Since that date, the strong motion network
has grown considerably, and the first strong motion
recording of an earthquake was obtained in Denizli on
19 August 1976, western Turkey. While the total
number of instruments was 120 up to 2001, at the
end of 2002 the total number of the instruments
reached to 163 (ERD, 2003). Ninety-six of these
accelerometers are digital, while 67 instruments are
analog. The accelerometric sites in Turkey are gener-
ally located along the North Anatolian and East
Anatolian Fault Zones and as well as in the southwest-
ern Anatolia. In addition to these instruments forming
the network, a limited number of temporary stations
installed by the Kandilli Observatory and Earthquake
Research Institute of Bogazic i University (KOERI),Ystanbul Technical University (ITU), USGS, Lomont-
Doberty Earth Observatory (LDEO, USA) and Uni-
versite Joseph Fourier after the devastating 1999
Kocaeli Earthquake are also present. The records of
these stations were downloaded from the web sites ofthe Consortium of Organizations for Strong Motion
Observation Systems (COSMOS, 2003) and USGS.
Some of the accelerometric data, available on the
Internet, do not include corresponding earthquake
characteristics (location and magnitude), and there
are some contradictions between different databases.
In order to decrease the number of unknowns and
uncertainties, and consequently improve the reliability
of the derived attenuation equation, additional data
associated with the earthquakes occurred in Turkey
were also found from the Internet sites of ETHZ
(2003), ISESD (2003), USGS-NEIC (2003), ISC
(2003) and HARVARD (2003). Among all-the three-
component accessible records between 1976 and No-
vember 2003, 221 records from 122 earthquakes of
Turkey were selected based on the criteria outlined in
the following paragraphs. Locations of the accelero-
metric sites in Turkey corresponding to the data
selected in this study are shown in Fig. 1.
Exclusion of records based on minimum PGA has
been proposed as selection criteria and they are
reviewed by Douglas (2003). In this study, the acce-
leograms with a PGAz 20 gal were selected consid-ering the criterion by Campbell (1981) to avoid bias in
Fig. 1. The locations of the strong ground motion stations of Turkey employed in this study.
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trigger threshold. The PGA data used in the analysis
were mostly from the stations founded in small
buildings, and the larger horizontal component of
each record was selected.The best scale for scientific and engineering pur-
poses is the moment magnitude (Mw) scale since it is
related to the rupture parameters. Therefore, in this
study earthquake size was characterized by Mw. Be-
cause smaller earthquakes are generally not of engi-
neering significance, the earthquakes with Mwz 4
were considered. However, the magnitudes of the
earthquakes occurred in Turkey are reported by dif-
ferent institutions in various scales. Based on the
database for a total of 170 events in Turkey occurred
between 1976 and November 2003, the numbers of
the magnitudes given by different institutions in Mw,Ms, Mb, Md and ML scales are 96, 95, 150, 75 and 69,
respectively. In other words, Mw values are not
available for all events. Therefore, it was decided to
derive moment magnitude for all records, to provide a
uniform and reliable scale for the attenuation relation-
ship, which was developed in this study. For the
purpose, values of Mw (from ETHZ and Harvard)
were correlated to Ms (from ETHZ, ISC, USGS,
Fig. 2. Correlations between the reported Mw, and the reported Ms, Mb, Md and ML values for Turkish earthquakes (r: correlation coefficient;
S.D.: standard deviation).
R. Ulusay et al. / Engineering Geology 74 (2004) 265291 269
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Harvard and ISESD), Mb (from ETHZ, ISC, USGS
and Harvard), Md and ML (from ERD) values. Using
data sets of 54, 92, 28 and 27 between MsMw, Mb
Mw, MdMw and MLMw, respectively, the relation-ship and conversion equations derived between Mwand other magnitude scales are given in Fig. 2. These
relationships yielded considerably high correlation
coefficients greater than 0.9. Of the 122 earthquakes
considered in this study based on the selection criteria,
magnitudes of 49 earthquakes have been directly
presented in Mw scale. Therefore, magnitudes in Mwscale for the rest (73 earthquakes) were derived from
the equations given in Fig. 2 (39, 18, 10 and 6 Mwvalues from Ms, Mb, Md and ML, respectively).
The distance to epicenter is the easiest measure to
use because the epicenter is the location information
given for all earthquakes. For small earthquakes, the
use of distance to epicenter in hazard analysis is
reasonably straightforward because easily available
catalogues of previous epicenters can be used as the
future sources or if line or surface source zones are
used then epicenters can be distributed on these
source zones (Douglas, 2003). For large-magnitude
earthquakes, the closest distance measures are gen-
erally preferred over the point source distances, such
as distance to the surface projection of the rupture
(e.g. Joyner and Boore, 1981) or rupture distance
(Campbell, 1981), at least for records from earth-quakes with Mw>6.5. However, for most of the
events, particularly for small events that have oc-
curred in Turkey, rupture surfaces have not been
defined clearly, and these distances are more difficult
to estimate. One of the other distance measures that
is available for most earthquakes is hypocentral
distance (Rh). However, accurate measures of focal
depth are often difficult, and therefore, estimation of
hypocentral distance is affected from this limitation.
Most damaging earthquakes occur within a shallow
region of the crust (about the top 30 km) and hence
Rh and distance to epicenter (Rc) become equal at
intermediate and large distances (Douglas, 2003). It
is also noted that the values of focal depth reported
by various institutions can be different as shown in
Fig. 3 for some earthquakes with Mw>5.5 from
Turkey. In this study, due to the abovementioned
reasons, distance to epicenter, Re, is preferred to be
used as site source distance in PGA estimation
relation. Minimum and maximum distance criteria
Fig. 3. Comparison of the depth values of some selected earthquakes of Turkey (Mw>5.5) reported by various institutions (earthquake numbers
refer to the earthquakes given in Table 1).
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are sometimes applied. A minimum distance criterion
of 2 km was applied by Wang et al. (1999) because
2 km is the minimum error in epicentral locations
and hence including records from smaller distancesmay give errors in the results. As mentioned by
Douglas (2003), only records associated with reliable
measures were used by some investigators (Camp-
bell, 1981; Sabetta and Pugliese, 1987) by including
only earthquakes with locations (epicenters or rup-
ture distance) known to within 5 km or less. On the
other hand, in the majority of the strong ground
motion relations suggested for tectonically active
regions (e.g. Boore et al., 1997; Campbell, 1997;
Sadigh et al., 1997) the upper bound for sitesource
distance is taken 100 km, which is the range where
ground motions have engineering significance.
Therefore, 5 and 100 km were taken as the lower
and upper bounds of the distance to epicenter,
respectively, and the records, for which the distance
to epicenter does not fall into this range were
omitted.
One of the extremely difficult items in determining
the site condition coefficient of the attenuation relation-
ships is the ground conditions. Local site conditions at
an acceleograph station can affect the strong motion
recorded. Therefore, attempts have been made in most
ground estimation relations to model the effect of near-surface ground conditions or strong motion. Data
selection criteria, which seek to limit the acceleograms
used to those recorded at stations with similar local site
conditions, are the simplest techniques. While the
widely accepted method quantitatively define the
near-surface material based on shear-wave velocity,
Vs, beneath the station. However, without consistent
site classifications for the attenuation relations, it is
often difficult to know how to apply the relations to a
specific site. But information on Vs is currently lacking
for the stations in Turkey. Based on their experiencewith the Iranian data, Zare and Bard (2002) classified
the records from Turkey for site conditions according
to the frequency band of the fundamental frequency
based on their H/V ratio. This ratio was chosen based
on the location of the broadened H/V spectral ratios
and the value of its amplitude. These investigators
suggest that this is the only method that may reveal
the site response, in the absence of any reliable geo-
logical and geotechnical data, such as Vs values. In
brief, Zare and Bard (2002) divided soil groups for
Turkey in ascending order for Vs and fundamental
frequency (fo) site category: 1rock and hard alluvial
soil corresponds to Vs>800 m/s, fo>15 Hz, site category
2alluvial sites (500 < Vs
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Table 1
Strong ground motion records used in the development of the attenuation relationship for peak ground acceleration (PGA) for Turkey
No. Station Code Station
coordinates
Earthquake
(date)
Epicenter
coordinates
Re(km)
PGA (gal) Site
C.
Mw
Lat. Lon. Lat. Lon. N S E W U D
1 Denizli Meteoroloji Mud. DNZ 37.814 29.112 19.08.1976 37.71 29 15.2 348.53 290.36 173.29 2 5.5a
2 Cerkes Meteoroloji Mud. CER 40.88 32.91 05.10.1977 41.01 33.57 57.2 36.03 38.94 16.18 3 5.8
3 Izmir Meteoroloji Mud. IZM 38.4 27.19 09.12.1977 38.35 27.23 6.6 158.91 272.97 87.25 2 5.2a
4 Malatya Meteoroloji Mud. MLT 38.35 38.34 21.09.1978 37.97 38.59 47.5 14.08 35.79 21.12 1 5.0a
5 Muradiye Meteoroloji Mud. M UR 39.03 43.7 11.04.1979 39.12 43.91 20.7 46.04 45.22 24.67 1 5.0a
6 Dursunbey Kandilli
Gozlem Ist.
DUR 39.67 28.53 18.07.1979 39.66 28.65 10.3 232.29 288.25 199.77 2 5.3
7 Hatay Bayindirlik ve
Iskan Mud.
HTY 36.25 36.11 30.06.1981 36.17 35.89 21.6 154.05 135.6 144.32 2 4.6a
8 Gonen Meteoroloji Mud. GNN 40.08 27.68 05.07.1983 40.33 27.21 48.6 50.11 46.77 37.68 2 6.1
9 Edincik Kandilli Gozlem Ist. EDC 40.36 27.89 05.07.1983 40.33 27.21 57.7 53.44 46.51 31.67 1 6.1
10 Tekirdag Meteoroloji Mud. TKR 40.96 27.53 05.07.1983 40.33 27.21 75.0 29.89 34.91 17.19 1 6.1
11 Edremit Meteoroloji Mud. EDR 39.61 27.03 05.07.1983 40.33 27.21 81.4 25.38 27.78 17.47 2 6.1
12 Balikesir Meteoroloji Mud. BLK 39.66 27.86 05.07.1983 40.33 27.21 92.7 22.55 20.71 24.72 2 6.1
13 Horasan Meteoroloji Mud. HRS 40.04 42.17 30.10.1983 40.35 42.18 34.4 173.3 150.26 87.92 2 6.6
14 Erzurum Meteoroloji Mud. ERZ 39.906 41.256 30.10.1983 40.35 42.18 92.7 35.49 24.99 31.94 1 6.6
15 Foca Gumruk Mud. FOC 38.64 26.77 17.06.1984 38.87 25.68 97.8 24.17 23 23.52 1 5.5b
16 Kigi Meteoroloji Mud. 39.34 40.28 12.08.1985 39.95 39.77 80.6 163.06 89.1 42.63 2 4.9a
17 Koycegiz Meteoroloji Mud. KOY 3 6.97 28.694 06.12.1985 36.97 28.85 13.8 103.24 114.46 68.59 2 5.1a
18 Golbasi Devlet Hastanesi GOL 37.781 37.641 05.05.1986 38.02 37.79 29.6 114.7 76.04 38.96 1 6.0
19 Kusadasi Meteoroloji Mud. KUS 37.861 27.266 01.06.1986 37.96 27.39 15.5 55.52 94.43 54.16 2 4.1c
20 Golbasi Devlet Hastanesi GOL 37.781 37.641 06.06.1986 38.01 37.91 34.7 68.54 34.42 18.01 1 5.8
21 Malatya Meteoroloji Mud. MLT 38.35 38.34 06.06.1986 38.01 37.91 53.2 23.57 24.81 26.04 1 5.8
22 Muradiye Meteoroloji Mud. MUR 39.03 43.7 20.04.1988 39.11 44.12 37.3 49.5 51.18 20.65 1 5.5
23 Foca Gumruk Mud. FOC 38.64 26.77 04.08.1988 38.86 27 31.5 31.61 41.4 28.32 1 4.7c
24 Istanbul Bayindirlik veIsk. Mud.
IST 41.08 29.09 12.02.1991 40.8 29.09 31.1 27.58 18.21 9.68 2 5.3a
25 Amasya Meteoroloji Mud. AMS 40.63 35.87 12.02.1992 40.58 35.8 8.1 37.1 29.03 2 4.94 3 5.1b
26 Erzincan Meteoroloji Mud. ERC 39.752 39.487 13.03.1992 39.72 39.63 12.7 470.92 404.97 238.55 2 6.6
27 Tercan Meteoroloji Mud. TER 39.777 40.391 13.03.1992 39.72 39.63 65.3 39.38 26.97 22.67 2 6.6
28 Refahiye Kaymakamlik
Binasi
REF 39.901 38.769 13.03.1992 39.72 39.63 76.2 67.21 85.93 31.57 2 6.6
29 Erzincan Meteoroloji Mud. ERC 39.752 39.487 15.03.1992 39.53 39.93 45.2 32.45 39.3 18.47 2 5.9
30 Erzincan Eksisu SERE 39.733 39.783 15.03.1992 39.53 39.93 25.8 112.5 40.7 3 5.9
31 Izmir Meteoroloji Mud. IZM 38.4 27.19 06.11.1992 38.16 26.99 31.8 30.49 38.34 21.19 2 6.0
32 Kusadasi Meteoroloji Mud. KUS 37.861 27.266 06.11.1992 38.16 26.99 41.1 83.49 71.8 62.1 2 6.0
33 Ilica Meteoroloji Mud. ILI 38.31 26.31 06.11.1992 38.16 26.99 61.6 16.65 37.81 25.77 2 6.0
34 Cesme Meteorological
Station
CES 38.333 26.317 06.11.1992 38.16 27 62.6 28.3 14.9 2 6.0
35 Islahiye Meteoroloji Mud. ISL 37.05 36.6 03.01.1994 37 35.84 67.6 20.57 19.43 19.14 2 5.3a
36 Foca Gumruk Mud. FOC 38.64 26.77 24.05.1994 38.66 26.54 20.1 36.06 49.8 29.6 1 5.5
37 Foca Gumruk Mud. FOC 38.64 26.77 24.05.1994 38.76 26.6 19.9 57.65 46.84 25.6 1 5.5a
38 Ilica Meteoroloji Mud. ILI 38.31 26.31 24.05.1994 38.76 26.6 56.0 24.91 26.88 14.6 2 5.5a
39 Koycegiz Meteoroloji Mud. KOY 36.97 28.694 13.11.1994 36.97 28.89 17.4 72.79 96.51 57.91 2 5.4a
40 Koycegiz Meteoroloji Mud. KOY 36.97 28.694 13.11.1994 37 28.82 11.7 26.6 20.78 20.63 2 4.7c
41 Koycegiz Meteoroloji Mud. KOY 36.97 28.694 13.11.1994 36.96 28.8 9.5 57.16 39.95 34.25 2 5.4
42 Koycegiz Meteoroloji Mud. KOY 36.97 28.694 13.11.1994 37.17 28.87 27.1 25.54 23.78 20.08 2 4.3d
43 Tercan Meteoroloji Mud. TER 39.777 40.391 29.01.1995 39.98 40.99 55.8 44.98 48.52 24.81 2 5.2
44 Van Bayindirlik ve
Iskan Mud.
VAN 38.504 43.406 26.02.1995 38.6 43.33 12.5 28 15.5 15.5 2 5.2b
45 Tekirdag Meteoroloji Mud. TKR 40.96 27.53 13.04.1995 40.85 27.67 16.9 38 45 11 1 5.0a
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No. Station Code Station
coordinates
Earthquake
(date)
Epicenter
coordinates
Re(km)
PGA (gal) Site
C.
Mw
Lat. Lon. Lat. Lon. N S E W U D46 Tekirdag Meteoroloji Mud. TKR 40.96 27.53 18.04.1995 40.8 27.84 31.5 25.5 34.5 8 1 4.9c
47 Dinar Meteoroloji Mud. DIN 38.06 30.155 26.09.1995 38.04 30.03 11.2 106 182.73 75.56 3 5.0a
48 Dinar Meteoroloji Mud. DIN 38.06 30.155 26.09.1995 38.09 30.01 13.1 54.26 81.02 48.77 3 5.1a
49 Dinar Meteoroloji Mud. DIN 38.06 30.155 27.09.1995 38.11 30.02 13.0 86.76 180.38 71.74 3 5.0a
50 Dinar Meteoroloji Mud. DIN 38.06 30.155 28.09.1995 38.56 30.47 61.9 39.62 42.72 12.11 3 4.2c
51 Dinar Meteoroloji Mud. DIN 38.06 30.155 01.10.1995 38.04 30.09 6.1 91.33 171.79 37.66 3 4.3c
52 Dinar Meteoroloji Mud. DIN 38.06 30.155 01.10.1995 38.11 30.05 10.7 281.63 329.72 150.68 3 6.4
53 Cardak Saglik Ocagi CRD 37.825 29.668 01.10.1995 38.11 30.05 46.0 65.07 61.3 98.47 2 6.4
54 Burdur Meteoroloji Mud. BRD 3 7.723 30.294 01.10.1995 38.11 30.05 48.0 41.61 43.92 33.86 2 6.4
55 Denizli Meteoroloji Mud. DNZ 37.814 29.112 01.10.1995 38.11 30.05 88.5 20 10 10 2 6.4
56 Dinar Meteoroloji Mud. DIN 38.06 30.155 01.10.1995 38.1 30.02 12.6 224.66 125.87 54.85 3 5.4a
57 Cardak Saglik Ocagi CRD 37.825 29.668 01.10.1995 38.1 30.02 43.4 24.83 20.87 13.18 2 5.4a
58 Dinar Meteoroloji Mud. DIN 38.06 30.155 03.10.1995 38.01 30.05 10.7 68.53 145.59 97.68 3 5.0
a
59 Dinar Meteoroloji Mud. DIN 38.06 30.155 05.10.1995 38.04 30.1 5.3 104.32 128.84 80.48 3 5.2b
60 Dinar Meteoroloji Mud. DIN 38.06 30.155 06.10.1995 38.03 30.09 6.6 98.85 168.08 44.57 3 5.0b
61 Dinar Cezaevi DCE 38.075 30.161 11.10.1995 38.12 30.18 5.3 44.74 41.14 1 5.93 2 4.3a
62 Dinar Jandarma Karakolu DJK 38.069 30.16 11.10.1995 38.12 30.18 5.9 31.31 63.6 13.18 2 4.3a
63 Dinar Devlet Hastanesi DDH 38.067 30.171 11.10.1995 38.12 30.18 5.9 40.53 25.15 13.31 1 4.3a
64 Dinar Koy Hizmetleri DKH 38.053 30.139 11.10.1995 38.12 30.18 8.3 86.24 47.18 14.53 2 4.3a
65 Erzincan Bayindirlik
ve Isk Mud.
ERC 39.743 39.512 05.12.1995 39.3 40.3 83.5 28.27 24.02 23.99 2 5.8
66 Erzincan Bayindirlik
ve Isk Mud.
ERC 39.743 39.512 05.12.1995 39.3 40.1 70.4 27.78 22.85 17.64 2 5.9a
67 Erzincan Bayindirlik
ve Isk Mud.
ERC 39.743 39.512 14.02.1996 39.61 39.23 28.3 47.91 38.47 35.15 2 4.2d
68 Kusadasi Meteoroloji Mud. KUS 37.861 27.266 20.02.1996 38.25 27.13 44.8 15.45 21.35 13.36 2 4.7b
69 Kusadasi Meteoroloji Mud. KUS 37.861 27.266 02.04.1996 37.78 26.64 55.7 21.33 33.44 22.46 2 5.470 Tekirdag Meteoroloji Mud. TKR 40.96 27.53 14.04.1996 40.8 27.45 19.0 10.5 21 7 1 4.1c
71 Osmancik Belediye Binasi OSM 4 0.97 34.83 14.08.1996 40.74 35.29 46.3 15.65 30.88 11.62 2 5.7
72 Amasya Bayindirlik
ve Isk Mud.
AMS 40.63 35.87 14.08.1996 40.74 35.29 50.3 26.5 54 25.5 3 5.7
73 Amasya Bayindirlik
ve Isk Mud.
AMS 40.63 35.87 14.08.1996 40.79 35.23 56.7 20 33.5 16.5 3 5.6
74 Merzifon Meteoroloji Mud. MRZ 40.88 35.49 14.08.1996 40.79 35.23 24.0 33.38 102.34 28.53 2 5.6
75 Buldan Kaymakamlik Binasi BLD 38.045 28.834 21.01.1997 38.12 28.92 11.2 24.37 38.51 28.02 2 5.2
76 Hatay Bayindirlik ve
Iskan Mud.
HTY 36.25 36.11 22.01.1997 36.14 36.12 12.2 134.5 149 89.5 2 5.7
77 Hatay Bayindirlik ve
Iskan Mud.
HTY 36.25 36.11 23.01.1997 36.16 36.33 22.1 27.5 19 16 2 4.1c
78 Amasya Bayindirlik
ve Isk. Mud.
AMS 40.63 35.87 28.02.1997 40.68 35.3 48.3 21 21 14.5 3 5.4a
79 Sakarya Bayindirlik
ve Isk. Mud.
SKR 40.739 30.384 21.10.1997 40.7 30.42 5.3 33.87 71.59 15.14 1 4.3a
80 Gelibolu Karayollari Mud. GLB 40.43 26.67 25.10.1997 40.49 26.43 21.3 42.42 19.43 8.75 2 5.2a
81 Edremit Meteoroloji Mud. EDR 39.583 27.016 05.03.1998 39.68 26.7 29.1 27.11 20.06 14.17 2 5.0a
82 Dinar Meteoroloji Mud. DIN 38.06 30.155 04.04.1998 38.14 30.04 13.4 134.73 130.9 27.71 3 5.2
83 Cardak Saglik Ocagi CRD 37.825 29.668 04.04.1998 38.14 30.04 47.8 24.48 27.88 19.15 2 5.2
84 Horasan Meteoroloji Mud. HRS 40.043 42.173 13.04.1998 39.91 41.61 50.1 38.5 32.5 23.5 2 5.2
85 Elazig Bayindirlik Mud. ELZ 38.672 39.193 09.05.1998 38.38 38.94 39.2 25.5 15 17.5 2 5.1
86 Ceyhan Tarim Ilce Mud. CYH 37.05 35.81 27.06.1998 36.85 35.55 32.0 273.55 223.28 86.47 3 6.3
Table 1 (continued)
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No. Station Code Station
coordinates
Earthquake
(date)
Epicenter
coordinates
Re(km)
PGA (gal) Site
C.
Mw
Lat. Lon. Lat. Lon. N S E W U D87 Karatas Meteoroloji Mud. KRT 36.561 35.367 27.06.1998 36.85 35.55 36.0 28.5 33.1 19.74 2 6.3
88 Mersin Meteoroloji Mud. MRS 36.83 34.65 27.06.1998 36.85 35.55 80.0 119.29 132.12 22.05 3 6.3
89 Hatay Bayindirlik ve
Iskan Mud.
HTY 36.213 36.16 27.06.1998 36.85 35.55 89.3 27.07 25.79 12.36 2 6.3
90 Islahiye Meteoroloji Mud. ISL 37.05 36.6 27.06.1998 36.85 35.55 95.8 21.35 18.22 14.11 2 6.3
91 Nacarli Koyu NAC 36.87 35.617 04.07.1998 36.84 35.44 16.1 24.1 20 19.6 1 5.4
92 Kilicli Koyu Ilkogretim
Okulu
KIL 37.081 35.455 04.07.1998 36.84 35.44 26.8 122.1 132.9 35.9 3 5.4
93 Baklal Koyu Saglik Ocagi BKL 37.033 35.633 04.07.1998 36.84 35.44 27.4 28.3 20.8 13.8 3 5.4
94 Mersin Meteoroloji Mud. MRS 36.83 34.65 04.07.1998 36.84 35.44 70.2 46.7 60.9 12.1 3 5.4
95 Baklali Koyu Saglik Ocagi BKL 37.033 35.633 04.07.1998 36.88 35.62 17.0 22 23.1 12.6 3 4.6a
96 Kilicli Koyu Ilkogretim
Okulu
KIL 37.081 35.455 04.07.1998 36.88 35.62 26.7 90 90.7 25 3 4.6a
97 Bornava Ziraat Fakultesi BRN 38.455 27.229 09.07.1998 38.08 26.68 63.4 27 12.5 5.6 3 5.0a
98 Horasan Tarim Ilce Mud. HRS 40.043 42.173 19.12.1998 39.82 42.13 25.0 26.5 19.5 14 2 4.9a
99 Elazig Bayindirlik Mud. ELZ 38.672 39.193 13.04.1999 38.53 39.25 16.5 12.5 31 9.5 2 4.5a
100 Tosya Meteoroloji Mud. TOS 41.013 34.037 16.06.1999 40.96 33.87 15.2 34.36 30.49 17.76 2 4.1a
101 Erzurum Bayindirlik
ve Isk. Mud.
ERZ 39.903 41.262 20.07.1999 39.53 41.28 41.4 33.51 29.88 23.5 1 4.8a
102 Yarimca Petkim Tesisleri 40.7639 29.762 17.08.1999 40.76 29.97 17.5 230.22 322.2 3 7.5
103 Sakarya Bayindirlik
ve Isk. Mud.
SKR 40.737 30.384 17.08.1999 40.76 29.97 34.9 407.04 259 1 7.5
104 Iznik Karayollari Sefligi IZN 40.437 29.691 17.08.1999 40.76 29.97 42.9 91.89 123.32 3 7.5
105 Gebze Tubitak Marmara
A. M.
GBZ 4 0.82 29.44 17.08.1999 40.76 29.97 45.1 284.82 141.45 2 7.5
106 Darica Arcelik Arge Binasi 40.8236 29.3607 17.08.1999 40.76 29.97 51.7 2 11.37 133.68 2 7.5
107 Heybeliada Sanatoryum HAS 40.8688 29.087 17.08.1999 40.76 29.97 75.2 56.15 110.23 1 7.5108 Goynuk Devlet Hastanesi GYN 40.385 30.734 17.08.1999 40.76 29.97 76.7 117.9 137.7 129.9 2 7.5
109 Istanbul Bayindirlik
ve Isk. Mud.
IST 41.08 29.09 17.08.1999 40.76 29.97 81.9 60.67 42.66 36.22 2 7.5
110 Levent Yapi Kredi Plaza 41.0811 29.0111 17.08.1999 40.76 29.97 88.0 41.08 35.52 1 7.5
111 Fatih Turbesi FAT 41.0196 28.95 17.08.1999 40.76 29.97 90.4 189.39 161.87 3 7.5
112 Bursa Tofas Fabrikasi 40.2605 29.068 17.08.1999 40.76 29.97 94.2 100.89 100.04 3 7.5
113 Bursa Sivil Savunma Mud. BRS 40.184 29.131 17.08.1999 40.76 29.97 95.5 54.32 45.81 25.73 2 7.5
114 Yesilkoy Havalimani 40.9823 28.8199 17.08.1999 40.76 29.97 99.7 90.21 84.47 2 7.5
115 ITU Istanbul Maslak MSK 41.104 29.019 17.08.1999 40.76 29.97 88.5 47.7 27.1 1 7.5
116 ITU Istanbul Mecidiyekoy MCD 41.065 28.997 17.08.1999 40.76 29.97 88.4 61.8 27.5 2 7.5
117 ITU Istanbul Zeytinburnu ZYT 4 0.986 28.908 17.08.1999 40.76 29.97 92.6 112 46.8 3 7.5
118 ITU Istanbul K.M.Pasa KMP 41.003 28.928 17.08.1999 40.76 29.97 91.6 128.3 84.2 3 7.5
119 ITU Istanbul Atakoy ATK 40.989 28.849 17.08.1999 40.76 29.97 97.5 161.1 61.6 3 7.5
120 Izmit Meteoroloji Istasyonu IZT 40.761 29.907 17.08.1999 40.76 29.97 5.3 219.2 139.2 1 7.5
121 Akyazi Orman Isletme
Mud.
. 40.67 30.622 22.08.1999 40.69 30.7 7.0 33.6 35 19.9 3 5.3a
122 Golyaka Jandarma Kislasi GLY 40.799 31.003 22.08.1999 40.69 30.7 28.3 27.5 21.4 9.9 3 5.3a
123 Yarimca Petkim 40.7639 29.762 31.08.1999 40.75 29.92 13.4 20.8 14 10.1 3 5.1
124 Sakarya Bayindirlik
ve Isk. Mud.
SKR 40.737 30.384 31.08.1999 40.75 29.92 39.1 24.41 17.06 8.42 1 5.1
125 Sapanca Saglik Ocagi SPN 40.688 30.257 31.08.1999 40.75 29.92 29.3 30.5 31.7 24.4 3 5.1
126 USGS Golden Station tyw 40.7 30.38 31.08.1999 40.75 29.92 39.5 23.50 24.69 14.66 3 5.1
127 USGS Golden Station KOR 40.76519 29.79347 31.08.1999 40.75 29.92 10.9 36.34 32.08 14.39 1 5.1
128 USGS Golden Station TUN 40.75704 29.78836 31.08.1999 40.75 29.92 11.2 46.34 56.97 24.18 2 5.1
129 USGS Golden Station TUS 40.75455 29.78965 31.08.1999 40.75 29.92 11.1 33.76 60.33 22.89 2 5.1
Table 1 (continued)
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No. Station Code Station
coordinates
Earthquake
(date)
Epicenter
coordinates
Re(km)
PGA (gal) Site
C.
Mw
Lat. Lon. Lat. Lon. N S E W U D130 USGS Golden Station TUW 40.75646 29.78672 31.08.1999 40.75 29.92 11.4 46.64 36.89 26.47 2 5.1
131 USGS Golden Station TYN 40.71192 30.39047 31.08.1999 40.75 29.92 40.3 17.71 19.89 9.40 3 5.1
132 USGS Golden Station TUN 40.75704 29.78836 31.08.1999 40.73 29.95 14.1 23.46 32.44 14.71 2 4.7a
133 USGS Golden Station TUS 40.75455 29.78965 31.08.1999 40.73 29.95 13.9 34.40 56.47 15.66 2 4.7a
134 USGS Golden Station TUW 40.75646 29.78671 31.08.1999 40.73 29.95 14.2 24.31 30.20 19.14 2 4.7a
135 USGS Golden Station KOR 40.76517 29.79343 06.09.1999 40.77 29.73 5.4 57.18 24.62 22.71 1 4.1c
136 USGS Golden Station TUW 40.75644 29.78671 06.09.1999 40.77 29.73 5.1 46.16 44.37 38.72 2 4.1c
137 Sakarya Bayindirlik
ve Isk. Mud.
40.737 30.384 13.09.1999 40.77 30.1 24.2 42.21 50.6 23.35 1 5.8
138 Yarimca Petkim . 40.7639 29.762 13.09.1999 40.77 30.1 28.5 86 89.9 50 3 5.8
139 Heybeliada Senatoryum . 40.8688 29.087 13.09.1999 40.77 30.1 85.9 19.2 35.4 31.6 1 5.8
140 Tepetarla Koyu Muhtar Evi . 40.72 30.079 13.09.1999 40.77 30.1 5.9 595.8 332.9 186.8 3 5.8
141 Bahcecik Seymen Kislasi . 40.71 29.907 13.09.1999 40.77 30.1 17.6 300.4 379.4 70.7 2 5.8142 USGS Golden Station KOR . 40.76505 29.79332 13.09.1999 40.77 30.1 26.1 91.10 108.40 58.30 1 5.8
143 USGS Golden Station SUB . 40.6869 29.49396 13.09.1999 40.77 30.1 52.5 29.40 42.00 18.60 1 5.8
144 USGS Golden Station DOR 40.77736 29.51404 13.09.1999 40.77 30.1 49.9 20.61 23.29 25.47 1 5.8
145 USGS Golden Station OIL 40.75551 29.78091 13.09.1999 40.77 30.1 27.2 151.51 164.09 54.42 2 5.8
146 USGS Golden Station TUW 40.75644 29.78668 13.09.1999 40.77 30.1 26.7 107.24 110.07 55.71 2 5.8
147 USGS Golden Station TYN 40.71190 30.39040 13.09.1999 40.77 30.1 25.6 56.24 52.41 21.63 3 5.8
148 USGS Golden Station TYR 40.73701 30.38008 13.09.1999 40.77 30.1 24.2 47.29 50.98 29.32 1 5.8
149 USGS Golden Station TYW 40.70923 30.39163 13.09.1999 40.77 30.1 25.8 46.41 47.20 24.86 3 5.8
150 USGS Golden Station TYR 40.73702 30.38009 17.09.1999 40.77 30.13 21.6 46.97 70.51 19.76 1 4.2a
151 Sakarya Bayindirlik
ve Isk. Mud.
SKR 40.737 30.384 19.09.1999 40.64 30.52 15.7 18.68 32.53 11.41 1 4.3a
152 USGS Golden Station TYR 40.73705 30.38010 24.09.1999 40.77 30.23 13.3 15.46 26.03 15.96 1 4.3d
153 Bahcecik S eymen Kislasi BHC 40.71 29.907 29.09.1999 40.74 29.33 49.0 74.2 91.5 21.6 2 5.2a
154 Sapanca Saglik Ocagi . 40.688 30.257 29.09.1999 40.74 29.33 78.8 21.2 17.6 10.2 3 5.2a
155 USGS Golden Station DOR 40.77736 29.51404 29.09.1999 40.74 29.33 16.3 200.24 182.35 70.88 1 5.2a
156 USGS Golden Station KOR 40.76512 29.79343 29.09.1999 40.74 29.33 39.6 58.59 109.65 21.08 1 5.2a
157 USGS Golden Station OIL 40.75549 29.78091 29.09.1999 40.74 29.33 38.5 219.49 208.36 28.68 2 5.2a
158 USGS Golden Station TUW 40.75644 29.78673 29.09.1999 40.74 29.33 39.0 92.98 125.71 26.67 2 5.2a
159 USGS Golden Station TYW 40.70924 30.39165 29.09.1999 40.74 29.33 90.7 18.17 26.65 8.77 3 5.2a
160 USGS Golden Station SUB . 40.6869 29.49396 29.09.1999 40.74 29.33 15.2 109.70 96.40 76.30 1 5.2a
161 USGS Golden Station YAR 40.64472 29.27490 20.10.1999 40.83 29.03 29.6 23.49 30.94 12.06 1 5.2a
162 LDEO Station No.
C0362 CH
. 40.67 30.666 07.11.1999 40.7 30.72 5.7 51.9 48 63.1 2 5.0a
163 LDEO Station No.
C1061
. 40.72 30.792 07.11.1999 40.7 30.72 6.5 62.7 138.5 64.3 2 5.0a
164 LDEO Station No.
C1060 BU
. 40.777 30.613 07.11.1999 40.7 30.72 12.5 35.3 25.2 24.4 1 5.0a
165 Sakarya Bayindirlik
ve Isk. Mud.
SKR 40.737 30.384 11.11.1999 40.81 30.2 17.5 206.54 345.28 133.33 1 5.6
166 Yarimca Petkim . 40.7639 29.762 11.11.1999 40.81 30.2 37.2 17.1 23.9 19.5 3 5.6
167 LDEO Station No.
C1060 BU
. 40.777 30.613 11.11.1999 40.81 30.2 35.2 31.4 41.6 44.4 1 5.6
168 LDEO Station No.
C1061
. 40.72 30.792 11.11.1999 40.81 30.2 51.2 44.4 50.8 20.1 2 5.6
169 Sakarya Bayindirlik
ve Isk. Mud.
SKR 40.737 30.384 11.11.1999 40.88 30.3 17.4 39.795 78.49 20.08 1 4.1c
170 Duzce Meteoroloji Mud. DZC 40.85 31.17 12.11.1999 40.74 31.21 12.7 407.69 513.78 339.64 3 7.2
Table 1 (continued)
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No. Station Code Station
coordinates
Earthquake
(date)
Epicenter
coordinates
Re(km)
PGA (gal) Site
C.
Mw
Lat. Lon. Lat. Lon. N S E W U D171 Mudurnu Kaymakamlik
Binasi
40.463 31.182 12.11.1999 40.74 31.21 30.8 120.99 58.34 1 7.2
172 Bolu Bayindirlik
ve Iskan Mud.
BOL 40.747 31.61 12.11.1999 40.74 31.21 33.7 739.51 805.88 200.13 3 7.2
173 Sakarya Bayindirlik
ve Isk. Mud.
SKR 40.737 30.384 12.11.1999 40.74 31.21 69.5 17.33 24.72 11.54 1 7.2
174 LDEO Station No.
C1058 BV
. 40.743 30.876 12.11.1999 40.74 31.21 28.3 109.1 71.4 71.5 2 7.2
175 LDEO Station No.
C1061
. 40.72 30.792 12.11.1999 40.74 31.21 35.5 124 100.7 48.6 2 7.2
176 LDEO Station No.
C0362 CH
. 40.67 30.666 12.11.1999 40.74 31.21 46.9 28 40.3 20 2 7.2
177 LDEO Station No.C1060 BU . 40.777 30.613 12.11.1999 40.74 31.21 50.8 51.5 29.8 20.2 1 7.2
178 Bolu Bayindirlik
ve Iskan Mud.
BOL 40.747 31.61 12.11.1999 40.75 31.1 42.9 21.13 18.07 7.79 3 5.6c
179 Bolu Bayindirlik
ve Iskan Mud.
BOL 40.747 31.61 12.11.1999 40.75 31.45 13.5 175.95 130.34 57.03 3 5.3c
180 Bolu Bayindirlik
ve Iskan Mud.
BOL 40.747 31.61 12.11.1999 40.75 31.4 17.7 59.11 60.32 18.7 3 5.4d
181 Bolu Bayindirlik
ve Iskan Mud.
BOL 40.747 31.61 12.11.1999 40.74 31.4 17.7 27.99 17.15 12.33 3 4.2c
182 Bolu Bayindirlik
ve Iskan Mud.
BOL 40.747 31.61 12.11.1999 40.75 31.36 21.0 26.23 25.26 21.25 3 4.8c
183 Bolu Bayindirlik
ve Iskan Mud.
BOL 40.747 31.61 12.11.1999 40.74 31.05 47.1 57.06 48.24 12.99 3 5.6d
184 Sakarya Bayindirlikve Isk. Mud.
SKR 40.737 30.384 13.11.1999 40.78 30.3 8.5 27.99 22.22 10.68 1 5.1a
185 LDEO Station No.
C1058 BV
. 40.755 31.015 13.11.1999 40.78 30.3 60.7 44.8 57.5 23 2 5.1a
186 Bolu Bayindirlik
ve Iskan Mud.
BOL 40.747 31.61 13.11.1999 40.75 31.4 17.7 46.75 34.66 14.2 3 4.0a
187 LDEO Station No.
C1058 BV
. 40.755 31.015 13.11.1999 40.83 31.02 8.4 23.1 22.3 16.3 2 5.0a
188 LDEO Station No.
C1061
. 40.72 30.792 13.11.1999 40.83 31.02 22.9 65.1 50.5 24 2 5.0a
189 Sakarya Bayindirlik
ve Isk. Mud.
SKR 40.737 30.384 15.11.1999 40.91 30.33 19.7 23.59 20.17 7.97 1 4.5a
190 Duzce Meteoroloji Mud. DZC 40.844 31.149 20.12.1999 40.87 31.01 12.0 20.45 18.75 19.01 3 4.1a
191 Bolu Bayindirlik
ve Iskan Mud.
BOL 4 0.747 31.61 05.01.2000 40.84 31.3 28.0 24.73 18 10.67 3 4.2c
192 Duzce Meteoroloji Mud. DZC 40.844 31.149 20.01.2000 40.76 31.33 17.8 35.44 55.18 17.26 3 4.8c
193 Duzce Meteoroloji Mud. DZC 4 0.844 31.149 14.02.2000 40.9 31.75 50.9 37.56 29.56 9.15 3 5.2d
194 Sakarya Bayindirlik
ve Isk. Mud.
SKR 40.737 30.384 02.04.2000 40.79 30.23 14.2 59.27 103.82 30.3 1 4.5
195 Denizli Meteoroloji Mud. DNZ 37.812 29.114 21.04.2000 37.85 29.27 14.3 27.56 17 18.13 2 5.4
196 Cerkes Meteoroloji Mud. CER 40.814 32.833 06.06.2000 40.72 32.87 10.9 62.46 63.16 40.25 3 6.1
197 Akyazi Orman Isletme
Mud.
40.67 30.622 23.08.2000 40.68 30.71 7.5 79.01 96.69 30.42 3 5.5
198 Sakarya Bayindirlik
ve Isk. Mud.
SKR 40.737 30.384 23.08.2000 40.68 30.71 28.2 20.84 27.47 15.63 1 5.5
199 Duzce Meteoroloji Mud. DZC 40.844 31.149 23.08.2000 40.68 30.71 41.2 23.29 17.55 9.25 3 5.5
Table 1 (continued)
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the purpose, the site conditions reported in the data-
bases of several institutions and the literature men-
tioned above are carefully compared, and the site
conditions, which were same in more than one data-
base reported by the institutions, were selected. For
the rest of the stations, for which different site con-
ditions are defined by various institutions, the infor-
mation from ERD (2003), Gulkan and Kalkan (2002),
Zare and Bard (2002), Durukal et al. (1998) and
ISESD (2003) were chosen. In addition, site condition
Table 1 (continued)
No. Station Code Station
coordinates
Earthquake
(date)
Epicenter
coordinates
Re(km)
PGA (gal) Site
C.
Mw
Lat. Lon. Lat. Lon. N S E W U D200 Iznik Karayollari Sefligi IZN 40.44 29.75 23.08.2000 40.68 30.71 85.3 21.69 16.21 8.25 3 5.5
201 Denizli Bayindirlik
ve Iskan Mud.
DNZ 37.813 29.114 04.10.2000 37.91 29.04 12.7 49.13 66.38 49.32 2 5.0
202 Burdur Bayindirlik
ve Iskan Mud.
BRD 37.704 30.221 02.02.2001 37.64 30.19 7.6 21.15 30.12 24.02 2 4.6c
203 Erzurum Bayindirlik
ve Isk. Mud.
ERZ 39.903 41.262 29.05.2001 39.85 41.55 25.2 21.88 17.21 15.14 1 4.9
204 Erzurum Bayindirlik
ve Isk. Mud.
ERZ 39.903 41.262 10.07.2001 39.8273 41.62 31.7 19.53 21.94 26.703 1 5.2
205 Bolu Bayindirlik
ve Iskan Mud.
BOL 40.747 31.61 26.08.2001 40.9455 31.5728 22.3 189.07 131.64 44.06 3 5.2
206 Van Bayindirlik
ve Iskan Mud.
VAN 38.504 43.406 02.12.2001 38.617 43.294 15.9 29.85 24.81 33.78 2 4.8
207 Afyon Bayindirlik
ve Iskan Mud.
AFY 38.792 30.561 03.02.2002 38.581 31.248 64.0 113.5 94 35.5 3 6.6
208 Afyon Bayindirlik
ve Iskan Mud.
AFY 38.792 30.561 03.02.2002 38.685 30.835 26.5 40.5 51.5 28 3 5.9
209 Burdur Bayindirlik
ve Iskan Mud.
BRD 37.704 30.221 03.04.2002 37.8128 30.2572 12.5 28.93 21.3 31.25 2 4.4d
210 Andirin Tufan Pasa
Ilkogretim O.
AND 3 7.58 36.34 14.12.2002 37.472 36.221 15.9 76.87 50.42 32.23 1 4.8
211 Akyazi Orman Isl. 40.67 30.622 09.03.2003 40.7328 30.6205 7.0 19.17 23.13 11.63 3 4.3d
212 Bornova Ziraat Fak. Dek. 38.455 27.229 10.04.2003 38.2568 26.8345 40.8 78.58 37.11 17.36 3 5.7
213 Bingol Bayindirlik
ve Iskan Mud.
38.897 40.503 01.05.2003 38.9737 40.534 8.9 152.25 74.62 35.86 2 4.7d
214 Bingol Bayindirlik
ve Iskan Mud.
38.897 40.503 01.05.2003 38.9613 40.341 15.7 19.62 20.23 14.16 2 4.2d
215 Duzce Meteoroloji
Istasyonu
40.844 31.149 21.05.2003 40.87 30.98 14.5 17.82 31.86 16.91 3 4.4
216 Canakkale Meteoroloji Ist. 40.142 26.4 06.07.2003 40.42 26.21 34.8 26.18 15.56 9.12 3 5.8
217 Saraykoy Jeotermal
Lojmanlari
37.932 28.923 23.07.2003 38.1718 28.8533 27.3 90.16 123.23 60.68 3 5.4
218 Denizli Bayindirlik
ve Isk. Mud.
37.813 29.114 23.07.2003 38.1718 28.8533 45.9 22.19 45.84 19.99 2 5.4
219 Saraykoy Jeotermal
Lojmanlari
37.932 28.923 26.07.2003 38.11 28.88 20.1 47.54 34.46 36.25 3 4.9
220 Saraykoy Jeotermal
Lojmanlari
37.932 28.923 26.07.2003 38.11 28.89 20.0 107.51 121.12 153.97 3 5.5
221 Denizli Bayindirlik
ve Isk. Mud.
37.813 29.114 26.072003 38.11 28.89 38.4 23.74 25.79 21.67 2 5.5
aConverted from Ms.b Converted from ML.c Converted from Mb.d Converted from Md.
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at Bingol station, which was observed by one of the
authors of this recent study (Aydan et al., 2003), was
also considered.
Some recent attenuation models distinguish be-tween the ground motion from reverse and strike slip
earthquakes with the ground motion from reverse
earthquakes being larger than for strike slip earth-
quakes. Due to the small number of normal faulting
earthquakes in most strong motion data sets, the
difference between ground motions for strike slip
and normal faulting earthquakes has not been included
in most attenuation relations (Douglas, 2003). The
observations performed in the last decade suggested
that even the hypocentral distance is the same; the
acceleration values may be different depending on the
place of the strong ground motion station with respect
to the causative fault and its hanging wall or footwall
(Abrahamson and Somerville, 1996; after Aydan and
Hasgur, 1997). Particularly accelerations recorded at
the stations founded on the hanging wall may be
greater than those obtained from the stations on the
footwall. Although effect of faulting type can be
important, Aydan and Hasgur (1997), who assessed
recorded acceleration values with fault type for some
Turkish earthquakes, indicated that type of faulting
seems to have less influence on the observed PGA
values. These investigators, however, suggested that
this aspect should be further checked in the light of
available data in the future. Gulkan and Kalkan (2002),
who more recently examined the peak ground motiondata from the small number of normal faulting and
reverse faulting earthquakes in the data set of Turkey,
indicated that they were not significantly different
from ground motion characteristics of strike slip char-
acteristics, and normal, reverse or strike slip earth-
quakes could be combined into a single fault category.
It is also noted that focal plane solutions of the most
earthquakes selected from the existing database for this
recent study are not available. Therefore, in this study,
type of faulting was not considered in the development
of the attenuation relationship.
Among all the three-component accessible records,
221 records were selected from 122 earthquakes oc-
curred between 1976 and November 2003 following
the data selection criteria outlined above (PGAz 20
gal, Mwz 4, and 5 km VReV 100 km). The data set
employed in this study is given in Table 1 and distri-
bution of all records with respect to magnitude, dis-
tance to epicenterand site condition is shown in Fig. 4.
Station names in Table 1 are given in Turkish and are
not translated. Based on this set of data, magnitudes of
the earthquakes ranged between 4.1 and 7.5 (Mw).
Fig. 4. The distribution of records in the database employed in this study in terms of magnitude, distance to epicenter and site conditions.
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3. Attenuation relationship development and
comparison with some selected relationships for
PGA
In the development of the attenuation relation-
ship, moment magnitude (Mw), distance to epicenter
(Re), site condition (SA and SB, where SA= SB =0 for
rock sites, SA= 1 and SB = 0 for soil sites, and SA= 0
and SB = 1 for soft soil sites) and recorded largest
horizontal PGA value of each station were employed.
A total of 55 rock sites, 94 soil sites and 72 soft
soil sites were considered in the analyses. In the
first stage of the analyses, one coefficient for each
of these terms was found via multiple regressions,
and an attenuation relationship was derived for
PGA. Then the PGA values predicted from this
relationship and the observed PGA values in the
database were subjected to non-linear regression to
obtain the final attenuation relationship. Based on
the analyses, the following attenuation relationship
was obtained.
PGA 2:18e0:021833:3MwRe7:8427SA18:9282SB 6
The variation of PGA with distance to epicenter for
rock, soil and soft soil sites with respect to different
values of Mw is shown in Fig. 5.
The general performance of the attenuation equa-
tion developed in this study is shown in Fig. 6, where
measured PGA values from the database are plotted
against predicted PGA values using Eq. (6). As seen
from Fig. 6, although a few points fall above and
below the lines with 1:0.5 and 1:2 slopes, which
indicate some overestimates and underestimates, re-
spectively, most of the predictions are scattered withinthese lines. Particularly smaller PGA values fall close
to the line 1:1. Correlation coefficient and standard
deviation corresponding to PGAobserved =PGApredictedcondition are 0.63 and 86.4, respectively.
The PGA values predicted from Eq. (6) were also
compared to those predicted from the domestic and
some imported attenuation relationships. For the pur-
pose, three domestic equations based on Turkish
database and developed by Inan et al. (1996), Aydan
(2001) and Gulkan and Kalkan (2002) were employed.
In the selection of imported equations for comparison,the following criteria were considered: (i) range of
magnitudes employed in derivation of the imported
equations should be similar those employed in this
study, (ii) distance measures employed should be
similar to that used in this study or should be available
from the reports of various institutions, and (iii) the
database employed in derivation of the imported
equations should be collected from the region with
tectonic regimes similar to that in Turkey. Two
imported equations generally satisfying the above-Fig. 5. Curves of PGA versus distance to epicenter for various
magnitudes and different site conditions.
Fig. 6. PGA values predicted from Eq. (6) versus observed PGA
values (r: correlation coefficient; S.D.: standard deviation; n:
number of data).
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mentioned criteria were found in literature. These were
developed by Theodulidis and Papzachos (1992) and
Ambraseys et al. (1996). Theodulidis and Papzachos
(1992) used a database consisting of 105 horizontalcomponents from shallow earthquakes in Greece of
magnitude 4.5 to 7.0, and of 16 horizontal components
from four shallow earthquakes in Japan and Alaska of
magnitudes 7.2 to 7.5. These investigators considered
Ms and Mw, and distance to epicenter as magnitude
scales and distance measure, respectively, and used
two site categories such as alluvium and rock sites.
Ambraseys et al. (1996) used 422 dada from shallow
earthquakes in Europe, Middle East and Turkey. They
considered distance to projection of rupture plane on
surface (Rcl) for the earthquakes with Ms > 6, otherwise
Re as a distance measure. They used four site con-
ditions as rock (1), stiff soil (2), soft soil (3) and very
soft soil (4), but considered only three because only
three records from very soft soil were available.
In order to compare Eq. (6) to the abovementioned
five attenuation relationships main shocks of five
great and one moderate earthquakes of Turkey (1992
Erzincan, 1995 Dinar, 1998 Adana-Ceyhan, 1999
Kocaeli, 1999 Duzce and 2000 Akyazy earthquakes)
with Mw > 6, and a total of three aftershocks from the
1998 Adana-Ceyhan and 1999 Kocaeli earthquakes
with Mw > 5 were selected from Table 1. During thecomparisons the following considerations were made:
(a) Because Aydans equation uses distance to
hypocenter and he preferred to employ focal
depths from ETHZ and if such parameters are not
available, then he utilizes the parameters deter-
mined by USGS or Harvard (Aydan, 2003), in
computations the depths reported by these
institutions were employed. By considering that
Ambraseys et al. (1996) and Gulkan and Kalkan
(2002) employ Rcl as a distance measure, amongthe selected earthquakes mentioned above, only
the earthquakes with known Rcl values, which
have been reported by the institutions were taken
into comparison. However, for some of smaller
events, rupture surfaces have not been defined
clearly, therefore, distances to epicenter were also
used for Gulkan and Kalkans equation when Rclis not available.
(b) Site condition categories 3 and 4 used by
Ambraseys et al. (1996) for soft and very soft
soils were combined into a single group as soft
soil. Because the equations developed by Aydan
(2001) and Theodulidis and Papzachos (1992)
use only two site conditions (rock and soil), in
Fig. 7. Comparison of data from the 1996 Erzincan (a) and 1995
Dinar (b) earthquakes with the curves of the attenuation relation-
ships at soil sites (h: focal depth; Re: distance to epicenter; Rcl:
closest horizontal distance between the recording station and a point
on the horizontal projection of the rupture zone on the earths
surface).
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Fig. 9. Comparison of data from the 1999 Kocaeli earthquake with
the curves of attenuation relationships at rock (a), soil (b) and soft
soil (c) sites.
Fig. 8. Comparison of data from the 1998 Adana-Ceyhan
earthquake at soil (a) and soft soil (b) sites, and the aftershock of
this earthquake at soft soil site (c) with the curves of the attenuation
relationships.
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. .
.
.
.
.
Fig. 10. Comparison of data from two aftershocks (a and b) of the 1999 Kocaeli earthquake with the curves of the attenuation relationships at
rock, soil and soft soil sites.
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this study, both equations were used for the
stations founded on both soil and soft soil sites.
(c) Although type of the magnitude for the equation
developed by Inan et al. (1996) has not beenmentioned in literature, these investigators are
from ERD, which generally reports the earth-
quakes in ML and Md scales. Therefore, one of
these two magnitude scales available was con-
sidered to predict the PGA values from Inan et
al.s equation.
(d) The comparisons for each earthquake with respect
to site conditions were made separately. However,
these equations employed different definitions for
source to site distance. By considering these
differences, x-axis was called source to site
distance (km), and the measured points are shown
by different symbols for Re and Rcl. In other
words, the performance of the equations devel-
oped by Ambraseys et al. (1996) and Gulkan and
Kalkan (2002) was evaluated using Rcl versus
PGA on the plots, which also show the curves of
the other relationships using Re.
The attenuation of PGA for the selected Turkish
earthquakes for rock, soil and soft soil sites are
compared in Figs. 7 12. The observed database
points from these events were also shown on these
Fig. 12. Comparison of data from the 2000 Akyazy earthquake with
the curves of the attenuation relationships at soft soil.
Fig. 11. Comparison of data from the 1999 Du zce earthquake with
the curves of the attenuation relationships at rock (a), soil (b) and
soft soil (c) sites.
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curves to illustrate how well they fit the predictions.
The comparisons indicate that although the attenua-
tion relationships suggested by Inan et al. (1996) and
Theodulidis and Papzachos (1992) show better fits toa few observed data, they generally considerably
overestimates the PGA values for different site con-
ditions. This overestimation becomes more evident
particularly at the near source areas and for big
earthquakes. The second attenuation relationship,
which was used for comparison and developed by
Ambraseys et al. (1996), generally underestimates
the peak acceleration values particularly for some
soil and soft soil sites (Figs. 8b,c, 10bsoil, 11c),
while slightly overestimates for rock sites (Figs. 9a
and 11a). Comparison of the other three relationships
developed using Turkish database (Aydan, 2001;
Gulkan and Kalkan, 2002; this study) suggests that
although many data points fall very close to the
curves representing these relationships, they also
yield some underestimations and overestimations.
Among the equations considered for comparison,
the equations developed in this study and by Aydan
(2001) generally yield similar estimates, which are
closer to the observed PGA values, particularly for
rock sites (Figs. 9a, 10b and 11a). It is also noted
that for soft soil sites during Duzce earthquake
Aydans equation yields a good estimation for Bolustation, while the estimation from the equation de-
veloped in this study is very close to that recorded at
Duzce station. In addition, for this earthquake all
equations compared in this study overestimate the
PGA values for soil sites. Aydan (2003) indicates
that the estimations of the PGA for this earthquake
probably deserve more detailed and sophisticated
functions by considering not only rupture propaga-
tion and ground conditions, but also the topograph-
ical effects.
4. Iso-acceleration map of Turkey
A probabilistic seismic hazard map of Turkey
constructed by Gulkan et al. (1993) replaced seismic
zones in Turkey, and a total of 72 different combina-
tions were used in Bayesian sense to derive a weight-
ed average map corresponding to four different
periods. Then, the seismic hazard zonation map based
on this probabilistic approach was published by the
Ministry of Public Works and Settlement of Turkey
(1996). Based on this map, Turkey is divided into five
subclasses of seismic zone with PGA values of >0.4g,
0.30.4g, 0 .2 0 .3g, 0 .1 0 .2g and < 0.1g ar eassigned for zones ranging from I to V, respectively.
The current practice in Turkey is to directly use the
PGA values from the seismic codes published by the
Ministry of Public Works and Settlement of Turkey
(1998). According to the codes, PGA values of 0.4g,
0.3g, 0.2g and 0.1g are assigned for zones ranging
from I to IV, respectively.
The seismic zoning map of Turkey has some set-
backs and these were outlined by Kayabali and Akin
(2002). In order to minimize the effects of the set-
backs in the present map, new seismic hazard maps
were constructed by Kayabali (2002) and Kayabali
and Akin (2002) using the probabilistic and determin-
istic approaches, respectively. However, Kayabali and
Akin (2002) indicate that the probabilistic-based maps
appear to have employed relatively large seismic
zones, and therefore, deterministic-based seismic
map seems to be more realistic. But in the construc-
tion of the iso-acceleration and seismic hazard maps
of Turkey by Kayabali and Akin (2002), they did not
consider fault segmentation concept and connected
the segments of the main faults of Turkey in their
assessments. In addition, they assumed that a faultwould create a surface rupture equivalent to 1/3 of its
total length and yield the maximum magnitudes.
These assumptions resulted in very long faults, and
consequently very high magnitudes were obtained
when compared to those of the earthquakes associated
with these faults. In this previous study, location of the
epicenters particularly those falling in the areas, where
active faults are not known, were not considered.
Based on the magnitudes estimated, they employed
the attenuation relationship proposed by Sadigh et al.
(1997), who did not account data from normal fault-ing, for the construction of an iso-acceleration and
seismic hazard maps of Turkey. In addition, the PGA
values picked up from the iso-acceleration map con-
structed by these investigators are for bedrock and it is
necessary to carry out site response analyses for the
sites underlain by soil to compute the maximum PGA.
A deterministic based iso-acceleration map of Tur-
key accounting different site conditions and based on
the PGA values derived from the attenuation relation-
ship developed in this study was also constructed. For
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the purpose, the active fault map of Turkey by Saroglu
et al. (1992) was employed as the main material to
define the earthquake sources. In addition, based on
the more recent studies on some active faults, whichhave not been shown on the map by Saroglu et al.
(1992), were also included in the present assessments.
A completed form of the active fault map employed in
this study is shown in Fig. 13a together with the
numbers assigned to the faults. The segments of the
main faults were not connected and each segment was
separately evaluated. Thus a total of 92 main faults (a
total of 141 individual faults) were considered in the
model. Name, length and type of each fault with the
references related to these faults are listed in Table 2.
It is apparent from Fig. 13a, that there are some
regions free from active faults. However, Fig. 13b
indicates the epicenters of a number of earthquakes,
which occurred between 1900 and November 2003,
appear in these regions. This situation suggest that
only the use of distances to the known active faults in
the attenuation relationship will result in unrealistic
PGA assignments for a series of points selected in
such regions. Therefore, in this recent study, the
epicenters were also decided to be used as the second
group of earthquake source.
For fault sources, the magnitude of the upper level
earthquake is usually estimated from fault dimensions.Before fault segmentation concepts were developed,
usually some fraction of the total fault length was used
to estimate the magnitude of the design earthquake.
For example, it was common to use 1/3 to 1/2 of the
total fault length for the estimation of maximum
magnitudes (Mark, 1977). Fault segmentation studies
have replaced this approach for well-studied faults
(Abrahamson, 2000). Therefore, in this study, use of
fault segments is considered to be more realistic in the
prediction of magnitudes, instead of connecting the
segments. For a specific fault, the moment magnitude
of the potential earthquake can be estimated by
relating it to the potential rupture length of the fault
using the relation proposed by Wells and Coppersmith
(1994). However, it was considered that use of a
relationship between magnitude and surface rupture
length based on Turkish earthquake data would be
more realistic. Therefore, the relation proposed by
Aydan (1997) was preferred. This relation is given in
Fig. 13. (a) Active faults compiled from several investigators to be used in this study, and (b) distribution of the epicenters of the earthquakes
occurred in Turkey between 1900 and March 2003.
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Table 2
List of active faults appearing in Fig. 13a and the information
associated with the faults considered in the construction of iso-
acceleration map
Fault
number
Fault name
(segment no.
in Fig. 7a)
Length
(km)
Fault
typeaMaximum
magnitude
(Mw)
assigned
Referenceb
1 NAFZ: Marmara
segment (1-1)
192.3 SS 7.5 2
(1-2) 192.5 SS 7.5 2
(1-3) 60.9 SS 6.6 2
2 NAFZ: Etili Sarikoy
segment (2-1)
60.5 SS 6.6 1
(2-2) 56.1 SS 6.5 1
(2-3) 237.7 SS 7.6 1
3 NAFZ: Yenice
Gonen Bursasegment (3-1)
73.6 SS 6.7 1
(3-2) 108.5 SS 7.0 1
4 NAFZ: Duzce
segment
66.7 SS 6.7 1
5 NAFZ: (5-1) 169.6 SS 7.4 1
(5-2) 98.6 SS 7.0 1
(5-3) 107.0 SS 7.0 1
(5-4) 310.5 SS 7.8 1
(5-5) 154.7 SS 7.3 1
6 Ezinepazari fault 262.5 SS 7.7 1
7 Akpinar Kirsehir
fault zone (7-1)
40.3 SS 6.3 3
(7-2) 23.6 SS 5.9 3
8 Tuzgolu fault zone 187.3 N 7.4 4
9 Gumuskent fault 94.3 SS 6.9 1
10 Ecemis fault zone
(10-1)
97.7 SS 7.0 4
(10-2) 128.2 SS 7.2 4
(10-3) 102.2 SS 7.0 4
(10-4) 55.3 SS 6.5 4
(10-5) 90.1 SS 6.9 4
11 Deliler fault 77.2 SS 6.8 1
12 MalatyaO vacik
fault zone (12-1)
107.5 SS 7.0 1
(12-2) 71.4 SS 6.7 1
(12-3) 64.0 SS 6.6 1
13 Elbistan fault 67.9 SS 6.7 114 Surgu fault 62.3 SS 6.6 1
15 EAFZ (15-1) 269.4 SS 7.7 1
(15-2) 207.4 SS 7.5 1
(15-3) 122.7 SS 7.1 1
16 Kavakbasi fault
(South of Mus)
86.5 SS 6.9 1
17 Mus thrust 88.1 T 6.9 1
18 Bingol Karakocan
fault
51.7 SS 6.5 1
19 Genc fault 26.4 SS 6.0 1
Fault
number
Fault name
(segment no.
in Fig. 7a)
Length
(km)
Fault
typeaMaximum
magnitude
(Mw)
assigned
Referenceb
20 South-East
Anatolian thrust
744.4 T 7.7 1
21 Semdinli Yuksekova
fault zone (21-1)
51.8 SS 6.5 1
(21-2) 47.1 SS 6.4 1
22 NA (22-1) 80.2 SS 6.8 1
Karacadag fault
(22-2)
22.2 U 5.8 1
23 NA (23-1) 18.3 SS 5.7 1
NA (23-2) 42.9 N 6.3 1
24 Bozova fault 51.6 SS 6.5 1
25 Tut fault 25.1 SS 5.9 1
26 Tutak fault (26-1) 108.0 SS 7.0 1Ercis fault (26-2) 33.7 SS 6.1 1
27 Caldiran fault 55.7 SS 6.5 1
28 Hasantimur lake fault 15.6 SS 5.6 1
29 Igdir fault (29-1) 67.9 SS 6.7 1
(29-1) 30.0 SS 6.1 1
30 Balik Golu fault
zone (30-1)
108.7 SS 7.0 1
(30-2) 41.3 SS 6.3 1
(30-3) 39.1 SS 6.3 1
31 Dogubayazit fault 50.8 SS 6.5 1
32 Kagizman fault 90.1 SS 6.9 1
33 Malazgirt fault 21.3 SS 5.8 1
34 Suphan fault 47.0 SS 6.4 1
35 Erzurum fault zone
(35-1)
168.6 SS 7.4 1
(35-2) 169.5 SS 7.4 1
(35-3) 29.7 SS 6.1 1
(35-4) 42.7 SS 6.3 1
(35-5) 57.0 SS 6.5 1
(35-6) 43.4 SS 6.3 1
(35-7) 44.0 SS 6.3 1
(35-8) 40.4 SS 6.3 1
36 KaratasOsmaniye
fault zone (36-1)
59.4 SS 6.6 1
(36-2) 29.9 SS 6.1 1
37 Osun fault 27.1 U 6.0 1
38 Mut fault zone 42.6 U 6.3 139 Karadag fault 23.6 U 5.9 1
40 Sultandagi fault 145.8 N 7.3 1
41 Burdur fault 59.1 N 6.6 1
42 Golhisar-Cameli
fault zone (42-1)
81.7 N 6.8 1
(42-2) 32.0 N 6.1 1
(42-3) 25.4 N 5.9 1
(42-4) 18.1 N 5.7 1
43 Dinar graben (43-1) 17.8 N 5.7 1
(43-2) 19.9 N 5.8 1
Table 2 (continued)
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two forms, as fault rupture length versus Ms (Aydan,
1997) and fault rupture length in logarithmic scale
versus Ms (Aydan et al., 2002). In this study, the latter
relation was employed (Fig. 14). Assuming that each
segment of a main fault and an individual fault would
create a surface rupture equal to its total lengthmeasured from the map shown in Fig. 13a the
maximum magnitudes (Ms) were estimated from Fig.
14 and, then converted to Mw using the equations
found from Fig. 2a (Table 2). However, only the Bitlis
suture zone extending throughout southeastern Ana-
tolia (Fig. 13a) was assumed to cause a surface
rupture equivalent to 1/3 of its total length, when it
is broken (Table 2).
For the construction of the iso-accelaration map of
Turkey, a computer program was written in BASIC
Fault
number
Fault name
(segment no.
in Fig. 7a)
Length
(km)
Fault
typeaMaximum
magnitude
(Mw)
assigned
Referenceb
44 Eskisehir Sultanhani
fault system (44-1)
76.3 N 6.8 5
(44-2) 58.2 N 6.6 5
(44-3) 77.9 N 6.8 5
(44-4) 40.4 N 6.3 5
45 Kaymaz fault 33.1 N 6.1 1
46 Eskisehir fault zone 43.3 N 6.3 1
47 Inonu Dodurga fault
zone (47-1)
77.2 N 6.8 1
(47-2) 38.5 N 6.2 1
48 Kutahya fault 40.3 N 6.3 1
49 Simav fault 56.6 N 6.5 1
50 Akhisar fault 35.3 N 6.2 151 ZeytindagBergama
fault zone
61.8 N 6.6 1
52 Aliaga fault 24.1 N 5.9 1
53 Demirkopru fault
(53-1)
16.7 N 5.6 1
(53-2) 14.1 N 5.5 1
54 Gediz graben (54-1) 130.2 N 7.2 1
(54-2) 168.9 N 7.4 1
55 Buyuk Menderes
graben (55-1)
134.7 N 7.2 1
(55-2) 189.0 N 7.5 1
56 Denizli Honaz fault 61.5 N 6.6 1
57 KaraovaMilas fault
(57-1)
44.6 N 6.4 1
(57-2) 36.9 N 6.2 1
58 Mugla Yatagan fault 46.3 N 6.4 1
59 Ula Oren fault zone 58.3 N 6.6 1
60 Sandikli fault (60-1) 28.5 N 6.0 1
(60-2) 20.9 N 5.8 1
61 Dazkiri .Cardak fault 41.5 N 6.3 1
62 Kas fault 19.8 N 5.7 1
63 Marmaris Koycegiz
fault (63-1)
18.2 N 5.7 1
(63-2) 18.1 N 5.7 1
64 Kumdanli fault 50.2 N 6.4 1
65 Beysehirgolu fault 29.5 N 6.0 1
66 GedizDumlupinarfault (66-1)
33.6 N 6.1 1
(66-2) 46.1 N 6.4 1
67 Sancak Uzunpinar
fault
50.4 SS 6.5 1
68 Merzifon fault 36.4 SS 6.2 1
69 Dodurga fault 19.7 SS 5.7 1
70 Derinkuyu fault 18.2 N 5.7 1
71 Fethiye fault 13.4 U 5.5 1
72 Bala fault 22.7 N 5.9 1
73 Edremit fault 52.3 N 6.5 1
74 NA 45.2 U 6.4 1
Table 2 (continued)
Fault
number
Fault name
(segment no.
in Fig. 7a)
Length
(km)
Fault
typeaMaximum
magnitude
(Mw)
assigned
Referenceb
75 Cildir lake fault 157.1 SS 7.3 1
76 Erivan fault 65.7 SS 6.7 1
77 KarsantiKaraisali
fault zone
65.6 SS 6.7 1
78 Altinekin fault 41.5 N 6.3 5
79 NA 11.2 U 5.3 1
80 NA 13.9 U 5.5 1
81 NA 24.0 SS 5.9 1
82 Trakya fault 102.2 SS 7.0 6
83 NA 17.5 U 5.7 1
84 NA 31.9 U 6.1 1
85 NA 16.5 U 5.6 1
86 NA 17.0 U 5.6 187 Sorgun fault 64.8 SS 6.6 4
88 Sarikaya
Akdagmadeni fault
77.4 SS 6.8 3
89 Delice (Yerkoy) fault 65.9 SS 6.7 3
90 Kirsehir fault 18.8 SS 5.7 3
91 Tatarli fault 48.2 N 6.4 1
92 Acigol fault (92-1) 46.8 N 6.4 1
(93-2) 35.9 N 6.2 1
NAFZ: North Anatolian Fault Zone; EAFZ: East Anatolian Fault
Zone.a SS: Strike slip fault; N: Normal fault; T: Thrust or reverse
fault; U: Although shown on the active fault map of Turkey
(Saroglu et al., 1992), information on fault type is not available.NA: Fault name is not assigned on the available maps.
b 1: Saroglu et al. (1992); 2: Stein et al. (1997); 3:Dirik (1998);
4: Dirik and Goncuoglu (1996); 5: Dirik and Erol (2003); 6: Yaltirak
et al. (1998).
Table 2 (continued)
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programming language. All faults and earthquake
epicenters were identified as a series of points and
as single points with global coordinates, respectively.
Then, the area between the coordinates of 25.545.5j
eastern longitudes and 35.542.5j northern latitudes
was divided by 0.1j intervals and a grid systemcomposed of 14271 points was obtained using the
computer program. The program calculated closest
distances to all faults shown in Fig. 13a and to the
epicenters (Fig 13b) for each grid point. For the
purpose, the points defining each fault zone wereconsidered and the two closest points on each fault
to the grid point under consideration were found.
Then the shortest distance between the grid point
and the fault was calculated. The distances from the
grids to the epicenters were also computed by the
program. The maximum magnitudes assigned to each
fault and/or segment (Table 2) and obtained from the
database for each epicenter were separately employed
in the attenuation relationship (Eq. (6)) suggested in
this study to predict the PGA for each point under
consideration. Then two iso-acceleration maps based
on these two approaches (fault segments and epi-
centers) were constructed. Finally, both maps were
compared by pixel to pixel and the highest of these
PGA values was assigned to each point. Fig. 15 shows
the final iso-accelaration map of Turkey constructed
by following the steps given above. It should be
remembered that the PGA values picked up from this
map is only for rock sites. In order to estimate the
values of PGA for soil and soft soil sites, the picked
up value from the map should be multiplied by 1.186
and 1.511, respectively.
As can be seen from Fig. 15, higher values of PGAare generally concentrated along the main seismotec-
Fig. 14. Relation between surface magnitude (Ms) and surface
rupture length (L) based on the Turkish earthquakes (after Aydan et
al., 2002).
Fig. 15. Base iso-acceleration map of Turkey constructed using the attenuation relationship suggested in this study (PGA contours are in gal and
represent rock sites; for soil and soft soil sites multiple the PGA value picked up from the map by 1.186 and 1.511, respectively).
R. Ulusay et al. / Engineering Geology 74 (2004) 265291288
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25/27
tonic features of Turkey. However, in addition to the
faults, the use of the distances to the epicenters, which
has not been considered in construction of the previ-
ous iso-acceleration maps of Turkey, enabled a betterconsideration on the PGA values to represent some
regions far from and/or free from the faults.
5. Conclusions
In this study, an attenuation relationship of PGA
based on the recent Turkish database was presented.
In addition, an attempt was made to construct an iso-
accelaration map using the proposed prediction model
and deterministic approach for Turkey. The proposed
attenuation relationship seems to be helpful for the
prediction of PGA for earthquakes with magnitude
(Mw) ranging between 4.1 and 7.5, and distance to
epicenter equal and/or less than 100 km with respect
to rock, soil and soft soil site conditions.
The comparison between the attenuation relation-
ship suggested in this study and some imported
relations developed using data from Europe and
Middle East indicated that the relationship of Theo-
dulidis and Papzachos (1992) considerably overesti-
mated the PGA values, while Ambraseys et al.s
(1996) equation generally yields underestimated val-ues particularly for soft soil sites. Similarly, the
relationship based on Turkish data and developed by
Inan et al. (1996) yields highly overestimated PGA
values, especially at near source areas. Among the
attenuation relationships used for comparison, the
equations developed for Turkey by Aydan (1997,
2001), Gulkan and Kalkan (2002) and the authors of
this study yield better match with observed data.
Therefore, it can be concluded that the use of atten-
uation relationships based on Turkeys own data
should be preferred to predict more precise PGAvalues.
The suggested iso-acceleration map, which is a
base map considering only rocky ground condition,
was constructed using the PGA values predicted from
a model based on the data from Turkey and also offers
an opportunity to estimate PGA values for soil and
soft soil site conditions when the given coefficients
for these site conditions are multiplied by the PGA
values picked up from the map for a certain point. It is
concluded that the map constructed can be considered
as a base map for a further modification of the
previously suggested seismic hazard zonation map
of Turkey.
Although the attenuation relationship developedin this study and the other two domestic relation-
ships (Aydan, 1997, 2001; Gulkan and Kalkan,
2002) mentioned above predict more precise PGA
values, it is recommended that in order to improve
the precision of the ground motion estimates site
characterization parameters based on shear-wave
velocity measurements at each station, which are
currently lacking in Turkey, need to be included
into the equations. In addition, as recommended by
Aydan and Hasgur (1997) and Aydan (2003) di-
rectivity effect, faulting type and the effect of
overhanging side on footwall should be considered
for when sufficient data on these factors become
available.
Acknowledgements
The authors would like to express their sincere
thanks to Dr. John Douglas and Dr. Mehdi Zare for
their critical reviews and valuable comments that lead
to significant