Seismic Microzonation

Seismic Hazard Assessment of KPK
UET
Presented By:
Muhammad Nouman
Supervised By:
Engr. Dr. Naveed Ahmad

2
Introduction
 Seismic hazard:
• A seismic hazard is the probability that an earthquake will occur in a given geographic area,
within a given window of time, and with ground motion intensity exceeding a given
threshold.
• With a hazard thus estimated, risk can be assessed and included in such areas as building
codes for standard buildings, designing larger buildings and infrastructure projects and
land use planning.
• In general terms, the seismic hazard defines the expected seismic ground motion at a site,
phenomenon which may result in destructions and losses.
Seismic Micro zonation
Presented by
Engr.M.Nouman, EEC UET Peshawar, KP.

3
Introduction
Presented by
 Seismic hazard:
• Two major approaches deterministic and probabilistic are worldwide used at present for
seismic hazard assessment.
• The deterministic approach takes into account a single, particular earthquake, the event
that is expected to produce the strongest level of shaking at the site.
• The outputs intensity, peak ground acceleration, peak ground velocity, peak ground
displacement, response spectra may be used directly in engineering applications.
• In the probabilistic approach, initiated with the pioneering work of Cornell, the seismic
hazard is estimated in terms of a ground motion parameter intensity, peak ground
acceleration and its annual probability of exceedance (or return period) at a site.
• The method yields regional seismic probability maps, displaying contours of maximum
ground motion (macroseismic intensity, PGA) of equal specified return period.

Steps of Cornel’s Approach of PSHA
1. Study Area.
2. Sources Used as per compilation.
3. Composite catalogue.
4. Regression Analysis.
5. Homogenization of catalogue.
6. Declustering of Catalogue.
7. Plotting the Declustered Catalogue
8. Completeness analysis.
9. Zoning.
10. Recurrence Models .
11. Hazard computation using CRISIS-2007.
Presented by

5
Introduction
 Area of Responsibility:
• The area for which seismic hazard is to be computed, which is Khyber Pakhtunkhwa (KPK)
in our case.
 Area of influence (AI):
• It is the region surrounding KPK Boundary in which if
any earthquake occurs will affect KPK.
• It is taken 200 Km area surrounding KPK.
Area of influence
200 KM
KPK
Presented by
Area of
Responsibility

6
Sources used in the compilation of the catalogue
• The seismic event data was collected From the Following Sources (year 1500 to 2016).
No. Sources
1 Ambrasey and Douglas (2004)
2 Ambrasey (2000)
3 Qittermeyer & Jacob (1979)
4 International Seismological Center
(ISC)
5 Global – CMT
6 National Geophysical Data Center
(NGDC)
7 USGS
Presented by
29.49824 S 38.72559 N
68.26591 W 75.88964 E

• All the sources data was merged in excel sheet and Combined or Composite catalogue was
formed.
• It Consisted of 12788 Earthquake events.
• The data is filtered and sorted.
• All the duplicate events are colored which were reported in two or more sources.
7
Combined Catalogue
Presented by

• Homogenization Relationships
8
Homogenization
Relationship
between
Relationship (Equation)
Mw & MS ≤ 6.2 Mw=0.5998Ms+2.3885
Mw& MS > 6.2 Mw=0.8573Ms+0.8806
Mw & Mb Mw=0.7998Mb+1.135
Mw & ML Mw=0.0487Ml+5.2428
Presented by

• Using the relationships shown above, all the sources data is converted to Mw.
9
Homogenization
Presented by

• Sources Priority
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Homogenization
Presented by
1) Ambrasey and Douglas
(2004)
2) Ambrasey (2000)
3) Qittermeyer & Jacob
(1979)
4) ISC
5) Global – CMT
6) NGDC
7) USGS

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The Homogenized Catalogue
Presented by

1. DE-CLUSTERING :
• Aftershocks And Foreshocks are temporally and spatially dependent on the main shocks.
• De-clustering is performed to remove these dependent events from the catalogue.
• The De-clustered Catalogue consists of independent events which is also known as
Independent Catalogue.
• The Method used is Gardner & Kenopoff 1974 De-clustering Algorithm.
• The De-Clustering was done using ZMAP programming in MATLAB.
12
Processing of Earthquake Catalogue
Presented by

13
The De-Clustered Catalogue
Presented by

2. Completeness analysis (Visual inspection method)
• One of the methods used for completeness is Visual Cumulative method (CUVI)
formulated by Mulargia and Tinti (1985).
• It is a simple, graphical procedure based on the observation that earthquakes follow
a stationary occurrence process.
• For a given magnitude class, the period of completeness is considered to begin at
the earliest time when the slope of the fitting curve can be well approximated by a
straight line.
14
Processing of Earthquake Catalogue
Presented by

15
Completeness analysis (Visual inspection method)
0
100
200
300
400
500
600
700
800
1950 1960 1970 1980 1990 2000 2010 2020
Cumulativeno.ofevents
Year
Completeness (4-4.5)
CP=1995
0
200
400
600
800
1000
1200
1950 1960 1970 1980 1990 2000 2010 2020
Year
Completeness (4.6-5)
0
50
100
150
200
250
300
350
1900 1920 1940 1960 1980 2000 2020 2040
Year
Completeness (5.1-5.5)
0
10
20
30
40
50
60
70
80
90
1880 1900 1920 1940 1960 1980 2000 2020 2040
Year
Completeness (5.6-6)
Presented by

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Mw Average Mw Interval Tc
4.0- 4.5 4.25 1995-2016 20
4.51 - 5.0 4.75 1984-2016 31
5.01 - 5.50 5.25 1973-2016 42
5.51 - 6.0 5.75 1961-2016 54
6.01 - 6.5.0 6.25 1931-2016 84
>= 6.6 6.75 1907-2016 108
0
5
10
15
20
25
30
35
1860 1880 1900 1920 1940 1960 1980 2000 2020 2040
Year
Completeness (6.1-6.5)
0
5
10
15
20
25
30
1490 1590 1690 1790 1890 1990 2090
Year
Completeness (6.6 onwards)
Processing of the earthquake catalogue
Presented by

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Seismic sources considered in the analysis
(Building Code of Pakistan)
Seismic Sources Georeferenced with map of Pakistan
Presented by

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Seismic Zones After De-clustering:
1. Shallow Seismic Zones ( Depth < 50km )
Presented by

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Shallow seismic zones with shallow events
Zone
No. of
Earthquakes
Minimum
Mw
Maximum
Mw
1 482 4 7.7
2 90 4.2 6
3 104 4.3 7.6
4 149 4 7.6
5 48 4 6.8
6 75 4.3 5.9
7 154 4.2 6.4
8 42 4.1 6.4
Presented by

20
Deep Earthquake Zones
Presented by

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Deep seismic Zones with Events
Zone No. of
Earthquakes
Minimum
Mw
Maximum
Mw
1 726 4 7.5
2 165 4 6.7
3 110 4.3 5.9
Presented by

• The Gutenberg–Richter law(GR law) expresses the relationship
between the magnitude and total number of earthquakes in any given
region and time period of at least that magnitude.
• Inputs for crisis needs the values of commutative frequency “N” or “λ”
which is the number of magnitude earthquakes per year. It can be
obtained from G-R relationship in recurrence model.
•
22
Gutenberg–Richter law
Presented by
log10 𝑁 = 𝑎 − 𝑏𝑀

23
Gutenberg Richter Models for Shallow Zones
N = 10 5.612-1.0599Mw
-2
-1.5
-1
-0.5
0
0.5
1
1.5
4 4.5 5 5.5 6 6.5 7
Cum.No.ofEQuakesperyear
Mw
G-R Model Shallow Zone 1
N = 10 3.879-0.9192Mw
-1.6
-1.4
-1.2
-1
-0.8
-0.6
-0.4
-0.2
0
4 4.5 5 5.5 6
Mw
N = 10 5.3967-1.1539Mw
-2.5
-2
-1.5
-1
-0.5
0
0.5
1
4 4.5 5 5.5 6 6.5
Mw
N = 10 4.996-1.0164Mw
-2.5
-2
-1.5
-1
-0.5
0
0.5
1
4 4.5 5 5.5 6 6.5 7
Mw
Presented by

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Gutenberg Richter Models for Shallow Zones
N = 10 4.3117-1.007Mw
-1.2
-1
-0.8
-0.6
-0.4
-0.2
0
0.2
4 4.2 4.4 4.6 4.8 5 5.2 5.4
Mw
y = 10 6.0562-1.3219Mw
-2
-1.5
-1
-0.5
0
0.5
1
4 4.5 5 5.5 6
Mw
N = 10 6.1028-1.2411Mw
-2.5
-2
-1.5
-1
-0.5
0
0.5
1
4 4.5 5 5.5 6 6.5
Mw
N = 10 4.104 -0.9684Mw
-1.2
-1
-0.8
-0.6
-0.4
-0.2
0
4 4.2 4.4 4.6 4.8 5 5.2 5.4
Mw
Presented by

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G-R Parameters for Shallow Zones
Seismic Zone a b
1 5.612 1.0599
2 3.879 0.9192
3 5.3967 1.1539
4 4.996 1.0164
5 4.3117 1.007
6 6.0562 1.3219
7 6.1028 1.2411
8 4.104 0.9684
Presented by

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G-R models for deep seismic zones
G-R Parameters for Deep Zones
N = 10 5.7137-1.2193Mw
-3
-2.5
-2
-1.5
-1
-0.5
0
0.5
1
4 4.5 5 5.5 6 6.5 7
Mw
G-R Model Deep ZONE 2
N = 10 4.6056-1.0108Mw
-1
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
4 4.2 4.4 4.6 4.8 5 5.2 5.4
Mw
Seismic Zone a b
1 4.9046 0.8564
2 5.7137 1.2193
3 4.6056 1.0108
N = 10 4.9046-0.8564Mw
-1
-0.5
0
0.5
1
1.5
4 4.5 5 5.5 6 6.5 7
Mw
Presented by

• Inputs for crisis needs the values of commutative frequency “λ” which
is the number of magnitude earthquakes per year. It can be obtained
from G-R relationship in recurrence model.
• Log (λ) = a-b*M
o α=a*2.303
o β=b*2.303
27
Hazard Computation Using CRISIS 2007
Presented by

• Shallow Zones
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CRISIS Input Parameters
Seismic Zone a b λ M0 Mmax α β
1 5.612 1.0599 23.57 4 6.8 12.92444 2.44095
2 3.879 0.9192 1.59 4 5.8 8.933337 2.116918
3 5.3967 1.1539 6.04 4 6.3 12.4286 2.657432
4 4.996 1.0164 8.52 4 6.8 11.50579 2.340769
5 4.3117 1.007 1.92 4 5.3 9.929845 2.319121
6 6.0562 1.3219 5.87 4 5.8 13.94743 3.044336
7 6.1028 1.2411 13.75 4 6.3 14.05475 2.858253
8 4.104 0.9684 1.7 4 5.3 9.451512 2.230225
Presented by

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• Deep Zones
CRISIS Input Parameters
Seismic Zone a b λ M0 Mmax α β
1 4.9046 0.8564 30.13 4 6.8 11.29529 1.972289
2 5.7137 1.2193 6.86 4 6.8 13.15865 2.808048
3 4.6056 1.0108 3.65 4 5.3 10.6067 2.327872
Presented by

 For Shallow Zones:
1. Akkar and Boomer ,2010
2. Bore and Atkinson,NGA 2008
 For Deep Zones:
1. Lin and Lee ,2008
2. Kanno et al.,2006
- Grid size used in the analysis = 0.05
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Ground Motion Prediction Equations
Presented by

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Ground Motion Maps
Presented by

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Levels Used in the Ground Motion Maps
The levels are divided according to the values used in Building Code
of Pakistan as follows:
1. ZONE 1 : 0.01-0.08 g
2. ZONE 2A : 0.08-0.16 g
3. ZONE 2B : 0.16-0.24 g
4. ZONE 3 : 0.24-0.32 g
5. ZONE 4 : > 0.32 g
Presented by

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Average of GMPEs Used for Shallow plus Deep Seismic Zones for 50yrs Return Period
Presented by

34Seismic Micro zonation
Presented by
Average of GMPEs Used for Shallow plus Deep Seismic Zones 100yrs Return Period

Presented by

Seismic Microzonation

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