CE 5603 Seismic Hazard Assessment
Middle East Technical University, Ankara,Turkey
Department of Civil Engineering
Prof. Dr. K. Önder Çetin
ASSIGNMENT 5 – Seismic Hazard Assessment
North Anatolian Fault (NAF) Segment Source Parameters are given below:
Length of Western NAF segment = 100 km
Width = 12 km
Faulting Mechanism = Strike Slip
Slip rate = 19 mm/year
Shear Modulus,  = 3.0 1011 dyne/cm2
b value = 0.9
Min magnitude = 5.0
Characteristic Magnitude = 7.0  0.25
PART I. HAZARD ASSESSMENT
Compute the PGA hazard for a rock site located 5 km off of the fault at a location 25
km from the east end measure along strike as shown in Figure 1. Compute the hazard
at PGA’s of 0.1 g, 0.2 g, 0.4 g, 0.6 g and 1.0 g. Plot the resulting hazard curve.
However, before you proceed to developing hazard curves, follow (answer) the
following relevant steps (questions):
a. Verify the characteristic magnitude.
b. The historical earthquakes recorded within last 100 years with moment
magnitudes greater than the minimum magnitude of interest are given in
Table 1. Estimate  and  parameters.
c. Estimate the annual rate of earthquakes with magnitude greater or equal to
minimum magnitude, N(Mmin), by balancing the moment rate for the
Youngs and Coppersmith (1985) characteristic model. Compare this value
by the value you have calculated in part b.
d. Now bin earthquakes starting from the minimum magnitude earthquake to
maximum magnitude earthquake in bin steps of 0.5 (i.e.: M w= 5.0-5.5
represented by Mw= 5.25). Estimate probability of earthquakes to be within
Assignment 5 : Seismic Hazard Assessment
1
CE 5603 Seismic Hazard Assessment
Middle East Technical University, Ankara,Turkey
Department of Civil Engineering
Prof. Dr. K. Önder Çetin
the corresponding bin intervals for the Youngs and Coppersmith (1985)
characteristic model.
e. Estimate the rupture area, rupture width and rupture length corresponding
to representative bin values (i.e. : Mw=5.25, 5.75, 6.25, 6.75, 7.25)
f. Estimate rupture distances for the ruptures centered in 10 km sections
shown in Figure 1. Assume that the distance to the down dip center of the
fault rupture is 6 km.
g. For the representative magnitudes defined in part d and rupture distances in
part f, estimate median and standard deviations of ln(PGArock) values by
using Sadigh et al. (1997) attenuation relationship.
h. By using the median and standard deviations of ln(PGArock) you have
calculated in part f, estimate the probabilities of PGArock exceeding the
values of 0.1 g, 0.2 g, 0.4 g, 0.6 g and 1.0 g for given representative
magnitudes and rupture distances.
i.
Now estimate the joint probability of exceedence of PGArock exceeding
the values of 0.1 g, 0.2 g, 0.4 g, 0.6 g and 1.0 g by multiplying the
corresponding probabilities of the realization of the events (i.e.:
P(Mw)*P(Rupture Area)*P(Rupture Width)*P(EQ X coordinate)*P(EQ y
coordinate) * P(PGArock>0.1g | Mw,rupture distance)
j. Estimate the annual rate of excedence, , by multiplying joint probability
you have calculated in part (i) with N(Mmin) value you have calculated in
part c.
k. Finally, estimate probability of PGArock exceeding the values of 0.1 g, 0.2
g, 0.4 g, 0.6 g and 1.0 g in 50 years by using Poisson’s process.
PART II. DEAGGREGATION OF HAZARD
a. Calculate and present the fraction contributions of different Magnitude
earthquakes on aggregated hazard for 50 years (i.e. : Calculate % fractions
of hazard corresponding to 5 magnitude bins centered at Mw=5.25, 5.75,
6.25, 6.75, 7.25; Present your findings as % fraction vs. Mw plot.)
b. Calculate and present the fraction contributions of rupture distances on
aggregated hazard for 50 years (i.e. : Calculate % fractions of hazard
Assignment 5 : Seismic Hazard Assessment
2
CE 5603 Seismic Hazard Assessment
Middle East Technical University, Ankara,Turkey
Department of Civil Engineering
Prof. Dr. K. Önder Çetin
corresponding to 7 rupture distance bins of 10 km intervals (e.g. : 0-10;
11-20; 21-30;… 61-70 ) ; Present your findings as % fraction vs. Rupture
distance plot.)
c. Calculate and present the fraction contributions of different Magnitude
earthquakes and rupture distances on aggregated hazard for 50 years (i.e.:
Calculate % fractions of hazard corresponding to 5 magnitude and 7
rupture distance bins (35 combinations)). Present your findings as %
Distance Down Dip (km)
fraction vs. Mw and Rupture distance, 3-dimensional plot.)
0
2
4
6
8
10
12
-50
-40
-30
-20
-10
0
10
20
30
40
50
Distance Along Strike (km)
Figure 1
Assignment 5 : Seismic Hazard Assessment
3
CE 5603 Seismic Hazard Assessment
Middle East Technical University, Ankara,Turkey
Mw
range
Mw,
rep
P(Mw)
Area
P(A)
5-5.5
5-5.5
5-5.5
5-5.5
5-5.5
5-5.5
5-5.5
5-5.5
5-5.5
5-5.5
5.25
5.25
5.25
5.25
5.25
5.25
5.25
5.25
5.25
5.25
0.541
0.541
0.541
0.541
0.541
0.541
0.541
0.541
0.541
0.541
20.18
20.18
20.18
20.18
20.18
20.18
20.18
20.18
20.18
20.18
1
1
1
1
1
1
1
1
1
1
Department of Civil Engineering
Prof. Dr. K. Önder Çetin
Width
Length
P(W)
ECx P(ECx) ECy P(ECy)
(km)
rup
Rup.
Dist.
ln (PGA) ln (PGA)
ln(0.1) ln(0.2)
median sigma
ln(0.4)
ln(0.6)
4.54
4.54
4.54
4.54
4.54
4.54
4.54
4.54
4.54
4.54
68.07
58.12
48.19
38.29
28.47
18.84
9.97
6.24
9.97
18.84
-4.6192
-4.3463
-4.0332
-3.6666
-3.226
-2.6799
-2.0088
-1.6464
-2.0088
-2.6799
-0.916
-0.916
-0.916
-0.916
-0.916
-0.916
-0.916
-0.916
-0.916
-0.916
-0.511
-0.511
-0.511
-0.511
-0.511
-0.511
-0.511
-0.511
-0.511
-0.511
1
1
1
1
1
1
1
1
1
1
4.44
4.44
4.44
4.44
4.44
4.44
4.44
4.44
4.44
4.44
45
35
25
15
5
-5
-15
-25
-35
-45
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
6
6
6
6
6
6
6
6
6
6
1
1
1
1
1
1
1
1
1
1
0.655
0.655
0.655
0.655
0.655
0.655
0.655
0.655
0.655
0.655
-2.303
-2.303
-2.303
-2.303
-2.303
-2.303
-2.303
-2.303
-2.303
-2.303
-1.609
-1.609
-1.609
-1.609
-1.609
-1.609
-1.609
-1.609
-1.609
-1.609
ln(1.0)
0
0
0
0
0
0
0
0
0
0
P(lnPGA>l P(lnPGA>l P(lnPGA>l P(lnPGA>l P(lnPGA>l Jnt Prob Jnt Prob Joint Prob Joint Prob Joint Prob
N(mmin)
0.4
0.6
1
n(0.1))
n(0.2))
n(0.4))
n(0.6))
n(1))
0.1
0.2
0.0002
0.0009
0.0041
0.0186
0.0793
0.2823
0.6731
0.8418
0.6731
0.2823
0.0000
0.0000
0.0001
0.0008
0.0068
0.0511
0.2710
0.4775
0.2710
0.0511
0.0000
0.0000
0.0000
0.0000
0.0002
0.0035
0.0477
0.1325
0.0477
0.0035
0.0000
0.0000
0.0000
0.0000
0.0000
0.0005
0.0111
0.0415
0.0111
0.0005
0.0000
0.0000
0.0000
0.0000
0.0000
0.0000
0.0011
0.0060
0.0011
0.0000
9.6E-07
4.3E-06
1.9E-05
8.8E-05
0.00038
0.00134
0.00319
0.00398
0.00319
0.00134
1E-08
7E-08
5E-07
4E-06
3E-05
0.0002
0.0013
0.0023
0.0013
0.0002
3.7E-11
3.9E-10
4.6E-09
6.3E-08
1E-06
1.7E-05
0.00023
0.00063
0.00023
1.7E-05
8.5E-13
1.1E-11
1.8E-10
3.4E-09
8E-08
2.2E-06
5.3E-05
0.0002
5.3E-05
2.2E-06
Sample Deaggregation Scheme (with respect to magnitude)
GRAND
i, 1 yr
i,50 yr
Assignment 5 : Seismic Hazard Assessment

x
x
x
x
x
50 yr
x
x
x
x
x
Mag
0.1 g
0.2 g
0.4 g
0.6 g
1.0 g
5.25
5.75
6.25
6.75
7.25
x
x
x
x
x
100
x
x
x
x
x
100
x
x
x
x
x
100
x
x
x
x
x
100
x
x
x
x
x
100
4
4.2E-15
7.7E-14
1.8E-12
5.1E-11
2E-09
1E-07
5.1E-06
2.8E-05
5.1E-06
1E-07
0.0875
0.0875
0.0875
0.0875
0.0875
0.0875
0.0875
0.0875
0.0875
0.0875
CE 5603 Seismic Hazard Assessment
Middle East Technical University, Ankara,Turkey
Department of Civil Engineering
Prof. Dr. K. Önder Çetin
Table 1
Event No
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Assignment 5 : Seismic Hazard Assessment
Date
15/04/1905
13/11/1948
03/06/1953
06/10/1964
06/10/1964
20/11/1965
09/11/1968
06/09/1970
21/07/1981
22/07/1981
09/06/1982
01/02/1983
03/11/1984
21/10/1987
27/10/1992
Magnitude
6.2
6.4
5.3
5.0
6.7
5.0
6.0
6.3
5.0
5.6
6.7
5.0
5.3
5.1
6.7
5