MALAYSIAN METEOROLOGICAL DEPARTMENT
MINISTRY OF SCIENCE, TECHNOLOGY AND
INNOVATION (MOSTI)
STUDY ON HYPOCENTER RELOCATION OF THE LOCAL
EARTHQUAKES IN MALAY PENINSULA USING THE
MODIFIED JOINT HYPOCENTER DETERMINATION
AND HYPOCENTER PROGRAMS
Project Leader:
Chai Mui Fatt
Researchers:
1. Zamuna binti Zainal
2. Devadas a/l Ramachandran
3. Zaty Aktar binti Mokhtar
4. Asmadi bin Abdul Wahab
5. Mohd Rosaidi bin Che Abas
Division:
Geophysics and Tsunami Division
Date Submitted:
18 August 2010
STUDY ON HYPOCENTER RELOCATION OF THE LOCAL
EARTHQUAKES IN MALAY PENINSULA USING THE MODIFIED
JOINT HYPOCENTER DETERMINATION AND HYPOCENTER
PROGRAMS
Chai Mui Fatt, Zamuna binti Zainal, Devadas a/l Ramachandran, Zaty Aktar binti Mokhtar,
Asmadi bin Abdul Wahab, and Mohd Rosaidi bin Che Abas
ABSTRACT
The formation of the fault lines in Malay Peninsula is associated with the
collision of the Indian Plate and the Eurasian Plate, which produced major
shear faults towards the east and the southeast in Southeast Asia. Two
complementary methods were used for hypocenter relocation using earthquake
information phases from the database archive at the Malaysian Meteorological
Department: Modified Joint Hypocenter Determination (Hurukawa, 2007) and
HYPOCENTER (Lienert, 1986). Both relocation programs have demonstrated
close agreement with USGS solution in verification of Southern Sumatra
earthquakes [2009]. Using the complementary methods, we have relocated 13
hypocenters of local earthquakes with magnitudes from 0.3 to 4.2 in Malay
Peninsula region. The nodal planes of the Manjong and Jerantut earthquake
are not well determined due of the insufficient data for analysis. For Manjong
Earthquake, the hypocenter, which was determined by the relocation
programs, is located near the offshore waters of Perak. Meanwhile, the
hypocenter of the Jerantut Earthquake which was determined by MJHD and
HYPOCENTER is located slightly north and south of the revised parameter,
respectively. However, hypocenter relocation for Bukit Tinggi and Kuala
Pilah earthquakes were dramatically improved by the programs. The
hypocenter programs had shown that the nodal plane of the Bukit Tinggi Fault
is striking NW-SE directions and dipping toward NE. Furthermore, MJHD
program had relocated three hypocentres along the Kuala Lumpur Fault and
the results are striking NW-SE directions and dipping toward SW. The NWSE trending faults are commonly associated with large quartz reefs along their
length. On the other hand, the nodal plane of the Kuala Pilah earthquakes is
striking SW-NE and dipping toward S. The epicentre distribution of the Kuala
Pilah earthquakes, determined by the relocation programs, follows the
curvilinear extension of Fault Line 2 of Seremban Fault Zone system.
TABLE OF CONTENTS
ABSTRACT
TABLE OF CONTENTS
1. INTRODUCTION
1.1 Seismicity and Tectonics Setting in Malaysia
1.1.1 Extrusion Tectonics
1.2 Major Fault Lines in Malay Peninsula
1.3 Local Earthquakes in Malay Peninsula
1.4 National Seismic Network of Malaysia
1.4.1 Weak Motion Stations
1.4.2 Strong Motion Stations
1.5 Hypocenter Determination Programs
1.5.1 Modified Joint Hypocenter Determination
1.5.2 HYPOCENTER
1.6 Scope of Study Areas
1.7 Purpose of Study
1
2
3
4
5
7
7
8
9
9
10
10
11
2. DATA
2.1 MiniSEED Data
2.2 Information Phases of the Local Earthquakes
2.3 Information Phases of the Southern Sumatra Earthquakes
11
11
11
14
3. THEORY AND METHODOLOGY
3.1 Processing Software
3.1.1 Obtaining P and S Phases from the Antelope
3.2 Verification of the Relocation Programs
3.3 Modified Joint Hypocenter Determination (MJHD)
3.3.1 Events and Stations Selection
3.3.2 Focus Decision
3.4 HYPOCENTER
3.4.1 Events and Stations Selection
3.5 Digitising of Fault Lines
18
18
18
19
21
21
22
22
22
23
4. RESULTS AND DISCUSSION
4.1 Verification of Programs with USGS
4.1.1 Antelope
4.1.2 MJHD
4.1.3 HYPOCENTER
4.2 Region 1 (R1) for Manjong Earthquake
4.3 Region 2 (R2) for Jerantut Earthquake
4.4 Region 3 (R3) for Bukit Tinggi Earthquakes
4.5 Region 4 (R4) for Kuala Pilah Earthquakes
4.6 Hypocenter Mapping of the Relocated Earthquakes
24
24
24
25
26
27
29
31
33
36
5. CONCLUSION
38
FUTURE PLAN
39
ACKNOWLEDGEMENT
39
APPENDICES
Appendix-1
Appendix-2
Appendix-3
Appendix-4
40
40
41
43
45
REFERENCES
49
1. INTRODUCTION
The Malay Peninsula is generally stable with a low seismicity profile. However, it is situated
rather close to the most active plate boundary between the Indian-Australian Plate and the
Eurasian Plate. The Indian-Australian Plate is actively subducting southwestward underneath
the Eurasian Plate. This subduction zone can rupture and can generate large tsunamis that
will have significant impacts on the countries in the Indian Ocean region. Major large
earthquakes that originated along the Sumatra fault and the subduction fault offshore of
Sumatra have resulted in tremors being felt in Malay Peninsula (Balendra et al., 2001) with
maximum intensity up to VII on the Modified Mercalli Intensity (MMI) scale. The closest
distance of these two major active faults from the Malay Peninsula is 300 km and 500 km,
respectively.
A tectonic model made by Metcalfe [2006] shows that Malay Peninsula is divided
into two tectonic blocks (Figure A-1-1 in Appendix-1). The suture line for this collision is
known as Raub-Bentong Suture. Most of the western and eastern coasts of Malay Peninsula
belong to Sibumasu Block and East Malaya Block, respectively. The reassessment of the
tectonic framework of Southeast Asia has indicated that East Malaya may well have been an
independent Cathaysian terrace at times in the Late Palaeozoic. The major fault lines in the
western part of Malay Peninsula consist of Kuala Lumpur Fault, Bukit Tinggi Fault,
Seremban Fault, Karak Fault, Bok Bak Fault and Kledang Fault. Meanwhile, in the eastern
part consist of Terengganu Fault, Lebir Fault, Lepar Fault and Mersing Fault (JMG, 2006).
They are mainly sinistral strike-slip with significant dip-slip components as shown by quartz
reefs along their length (Hutchison and Tan, 2009).
Generally, fault lines in the Malay Peninsula appeared to be infrequent and inactive.
However, a series of large earthquakes in recent years had changed the tectonic setting in the
Southeast Asian region, including the Malay Peninsula. The series of seismic activities is
believed as preliminary indications of the reactivation of major fault lines in Malay
Peninsula. Therefore, many seismologists believed that the reactivation of the faults system in
Malay Peninsula was associated with the great Sumatra-Andaman Earthquake (26 December
2004), Nias Earthquake (28 March 2005) and Bengkulu Earthquake (12 September 2007).
Subsequently, local earthquakes that had occurred in Bukit Tinggi (between 30 November
2007 to 25 May 2008), Jerantut (17 March 2009), Manjong (29 April 2009) and Kuala Pilah
(29-30 November 2009) are associated with these events. Recently, the Southern Sumatra
Earthquake that occurred on 30 September 2009 had reactivated again the Bukit Tinggi Fault
system, and caused a series of 7 weak local earthquakes around the Bukit Tinggi area (8
October and 4 December 2009).
To increase the capability of the National Seismic Network of Malaysia for efficient
earthquakes detection, the Malaysian Meteorological Department (MMD) has installed ten
strong motion stations in Klang Valley area and one broadband station in Jerantut, Pahang.
The purpose is to monitor the local earthquakes activities closely. Apart from that, MMD has
been coordinating with several agencies in the effort to increase awareness among the media
and public regarding disasters such as earthquake and tsunami hazards on the community
level.
1
1.1 Seismicity and Tectonics Setting in Malaysia
Geographically, Indosinia-Sundaland is a region that comprised of the Malay Peninsula and
Maritime Southeast Asia islands of Sumatra, Java, Borneo and surrounding smaller islands.
Malaysia is located in the region of Indosinia-Sundaland which is considered a geologically
stable condition. However, it is also situated close to the active volcanoes and the most
seismically active plate boundaries between the Indian-Australian Plate and Eurasian Plate in
the west and between Philippine Plate and Eurasian Plate in the east (Figure 1). The
convergence of the Indian-Australian Plate and the Pacific Plate against the Eurasian Plate is
6 cm/year and 11 cm/year, respectively (Tjia, 2008).
Generally, Malaysia is considered as a country with relatively stable and low seismicity
profile except for the state of Sabah. Therefore, Malaysia is facing a certain degree of
earthquake risks from both distant and local earthquakes, particularly in Sabah. Major
earthquakes with long period surface waves originating from active seismic areas along the
subduction zones in west coast of Sumatra (e.g. Southern Sumatra Earthquake on 30
September 2009), Sulawesi and Philippines have been felt especially in the west coast of
Peninsular Malaysia and Sabah. Thus, empirical evidence suggests that Malaysia is not
totally free from seismic risks.
Figure 1: Earthquake-prone region of Malaysia (Tjia, 2008).
2
1.1.1 Extrusion Tectonics
The collision of India and Asia have caused large strike-slip faults to form, and resulted in the
extrusion of crustal blocks towards the southeast since the Eocene as a result of the
indentation of rigid India into Asia (Peltzer and Tapponnier, 1988, Tapponnier et al., 1982).
The result of the relative motion between a rigid Indochina (Sundaland) block and China
(Briais et al., 1993) suggests that the block on South China Sea to be opened.
According to Tjia [2009] the formation of the fault lines in Malay Peninsula is associated
with the collision of the Indian Plate and Eurasian Plate, which produced major shear faults
towards the east and the southeast in Southeast Asia (Figure 2). The geophysical evidence,
derived from the pattern of magnetic stripes in the Indian Ocean, indicates that the northward
motion of India, with respect to Asia, slowed from about 100 mm a year to about 50 mm a
year at this time. This lower rate continues to the present day. As a result, almost 2500 km of
convergence between the two has occurred since collision, shortening and thickening the
crust to produce the Himalayan mountain chain and the Tibetan Plateau.
Su
Me
IC
Sundaland
Mentawei
Indochina
SC
South China
Figure 2. Extrusion Tectonics had produced major shear faults towards southeast (yellow
arrow 1) and east (yellow arrow 2) in Southeast Asia region (P. Tapponnier et al., 1982).
3
1.2 Major Fault Lines in Malay Peninsula
Malay Peninsula consists of several major fault lines that exist during the evolution of Upper
Palaeozoic and Mesozoic strata (Harbury, 1990). The major fault lines are Bok Bak Fault,
Lebir Fault, Terengganu Fault, Bukit Tinggi Fault, Kuala Lumpur Fault, Lepar Fault and
Mersing Fault (Figure 3). They are commonly NW-SE trending faults as associated with
large quartz reefs along their length. Generally, fault lines in Malay Peninsula are delineated
as infrequent and inactive. However, a large earthquake that occurred in recent years due to
stress release had changed the tectonic setting in Malay Peninsula. The series of seismic
activities in the recent years had reactivated some of the fault lines in this region (e.g. Bukit
Tinggi Fault, Lepar Fault and Seremban Fault zone).
2
3
1
6
4
5
7
Figure 3. Seismotectonic map of Malay Peninsula (JMG, 2006). 1. Bok Bak Fault, 2. Lebir
Fault, 3. Terengganu Fault, 4. Bukit Tinggi Fault, 5. Kuala Lumpur Fault, 6. Lepar Fault and
7. Mersing Fault.
4
1.3 Local Earthquakes in Malay Peninsula
Malaysia had also experienced earthquakes of local origin (Figure 4 and Table 1). These local
earthquakes are associated with active faults that exist in Malay Peninsula. However, several
possible active faults have been delineated and local earthquakes in Malay Peninsula are
appearing to be isolated and infrequent. Induced earthquakes (JMM and ASM, 2009) have
been instrumentally recorded in Terengganu when the large Kenyir Reservoir began filling up
in 1984. Later in 1985, a series of weak earthquakes had occurred at the man-made Kenyir
Lake due to the water impounding processes.
B
C
A
D
Figure 4. Epicentre of the local origin earthquakes recorded from 2007 to 2009 in
Malay Peninsula. A, B, C and D are labelled as Lepar Fault, Bukit Tinggi Fault, Kuala
Lumpur Fault and Seremban Fault zone system, respectively.
5
Between 30 November 2007 and 25 May 2008, a total of 19 weak earthquakes with
magnitudes ranging from 1.4 to 3.8 on Richter scale had occurred in Bukit Tinggi area,
Pahang. The epicentres are located within the Bukit Tinggi Fault zone, and the orientation
trend is more to NW-SE of the fault (Hutchison and Tan, 2009). Therefore, the occurrences
of these earthquakes are associated with a motion along the Bukit Tinggi Fault zone.
Recently in between 08 October 2009 to 04 December 2009, a total of 7 weak earthquakes
had occurred within this area. It is believed that the re-occurrences of the Bukit Tinggi
earthquake are related to stress release as a result of the Southern Sumatra Earthquake (30
September 2009). Furthermore, a total of 6 weak earthquakes occurred in Malay Peninsula.
The earthquake distributions are each one event for Jerantut (Pahang) and Manjong (Perak),
and 4 events in Kuala Pilah (Negeri Sembilan).
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
Table 1. Event of local earthquakes in Malay Peninsula (2007-2009) (MMD, 2010)
Date
OT
Lat
Long
Mb
Depth
Region
0
0
(UTC)
( N)
( E)
(km)
30-Nov-07
30-Nov-07
30-Nov-07
04-Dec-07
04-Dec-07
06-Dec-07
09-Dec-07
12-Dec-07
31-Dec-07
10-Jan-08
13-Jan-08
13-Jan-08
13-Jan-08
14-Jan-08
14-Jan-08
14-Mar-08
14-Mar-08
15-Mar-08
25-May-08
27-Mar-09
29-Apr-09
07-Oct-09
07-Oct-09
07-Oct-09
07-Oct-09
07-Oct-09
08-Oct-09
29 Nov-09
29 Nov-09
30 Nov-09
30 Nov-09
04 Dec-09
02:13
02:42
12:42
10:12
19:57
15:23
12:55
10:01
09:19
15:38
02.24
10:18
15:59
15:45
16:41
23:16:18
23:35:24
00:50:57
01:36:20
01:46:26
13:53:55
21:21:26
21:26:07
21.51:11
22:09:47
22:20:55
04:05:55
06:26:51
16:15:05
01:12:30
06:29:48
01:41:45
3.36
3.34
3.31
3.36
3.37
3.36
3.33
3.47
3.32
3.39
3.31
3.33
3.41
3.42
3.35
3.33
3.30
3.33
3.36
3.872
4.150
3.350
3.355
3.353
3.352
3.349
3.354
2.739
2.736
2.738
2.731
3.354
101.80
101.80
101.84
101.81
101.81
101.81
101.82
101.79
101.81
101.73
101.83
101.83
101.86
101.80
101.77
101.74
101.86
101.71
101.75
102.530
100.729
101.809
101.821
101.821
101.816
101.817
101.805
102.091
102.117
102.143
102.067
101.805
Remark: OT is origin time in UTC.
6
3.5
2.8
3.3
3.0
3.3
2.7
3.5
3.2
2.6
3.0
2.5
2.4
1.9
3.4
2.5
2.9
2.5
3.3
2.6
3.2
2.8
2.0
1.0
4.2
3.2
0.3
1.9
3.1
3.3
3.0
3.5
1.9
2.3
<10
6.7
<10
<10
<10
4.9
<10
3.0
1.2
<10
<10
3.0
2.1
0.0
0.0
0.0
0.0
0.0
50.0
23.0
2.0
1.0
3.0
2.0
3.0
3.0
3.0
3.0
4.0
15.0
3.0
Bukit Tinggi, Pahang
Bukit Tinggi, Pahang
Bukit Tinggi, Pahang
Bukit Tinggi, Pahang
Bukit Tinggi, Pahang
Bukit Tinggi, Pahang
Bukit Tinggi, Pahang
Bukit Tinggi, Pahang
Bukit Tinggi, Pahang
Bukit Tinggi, Pahang
Bukit Tinggi, Pahang
Bukit Tinggi, Pahang
Bukit Tinggi, Pahang
Bukit Tinggi, Pahang
Bukit Tinggi, Pahang
Bukit Tinggi, Pahang
Bukit Tinggi, Pahang
Bukit Tinggi, Pahang
Bukit Tinggi, Pahang
Jerantut, Pahang
Manjong, Perak
Bukit Tinggi, Pahang
Bukit Tinggi, Pahang
Bukit Tinggi, Pahang
Bukit Tinggi, Pahang
Bukit Tinggi, Pahang
Bukit Tinggi, Pahang
Kuala Pilah
Kuala Pilah
Kuala Pilah
Kuala Pilah
Bukit Tinggi, Pahang
1.4 National Seismic Network of Malaysia
1.4.1 Weak Motion Stations
Currently, the Malaysian Meteorological Department operates a total of 17 seismological
stations throughout the country with 10 broadband seismometers (Streckeisen STS-2) and 7
short period seismometers (SS-1 Ranger) as shown in Figure 5. The seismic stations are
located at Kulim, Ipoh, Kuala Lumpur, Kluang, Kota Tinggi, Kuala Terengganu, Jerantut,
Kuching, Sibu, Bintulu, Bakun, Kota Kinabalu, Kudat, Sandakan, Lahad Datu, Sapulut and
Tawau. The detailed information of these stations is described in Table 2.
The current real time digital seismic network is able to detect earthquakes and acquire
digital seismic waves from various seismometers and accelerometers. Each remote
seismological station is installed with three components weak motion seismometer and strong
motion accelerometer (Episensor). The real time data is transmitted via VSAT telemetry
using 256 kbps digital leased line communication from the service provider’s satellite
gateway to the central processing centre in headquarter of MMD for processing, analysis and
dissemination.
The central processing centre runs Boulder Real Time Technologies (BRTT)
Antelope system as processing software on SUN Blade for real time and post processing
base. BRTT provides software which supports the collection, archiving, integration, and
processing of environment sensors, particularly seismic sensors. The Antelope Real Time
System (ARTS) is providing automatic and manual event detections, arrival picking,
locations and magnitude calculation. MMD is also using SeismComP3 and EarlyBird
processing software for comparison purpose with Antelope.
KTM
KUM
IPM
JRM
FRM
KGM KOM
KDM
KKM
SDM
SPM LDM
BTM
TSM
SBM
BNM
KSM
Figure 5. Locations of seismic stations in Malaysia. (Blue triangles: stations with
Streckeisen STS-2 seismometers, yellow triangles: new stations with Streckeisen
STS-2 seismometers, green triangles: stations with SS-1 Ranger seismometers).
7
No
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
Table 2. Detailed information of the Malaysian seismic stations.
Station
Seismic Station Name
Latitude
Longitude
Code
(0N)
(0E)
BNM
Bakun, Sawarak
2.7767
114.0350
BTM
Bintulu, Sawarak
3.2000
113.0833
FRM
FRIM Kepong, Selangor
3.2333
101.6333
IPM
Ipoh, Perak
4.4795
101.0255
JRM
Jerantut, Pahang
3.8867
102.4767
KDM
Kudat, Sabah
6.9167
116.8333
KGM
Kluang, Johor
2.0157
103.3190
KKM
Kota Kinabalu, Sabah
6.0443
116.2147
KOM
Kota Tinggi, Johor
1.7922
103.8467
KSM
Kuching, Sawarak
1.4733
110.3083
KTM
Kuala Terengganu, Terengganu
5.3283
103.1356
KUM
Kulim, Kedah
5.2902
100.6492
LDM
Lahad Datu, Sabah
5.1777
118.4980
SBM
Sibu, Sawarak
2.4529
112.2140
SDM
Sandakan, Sabah
5.6409
117.1950
SPM
Sapulut, Sabah
4.7083
116.4650
TSM
Tawau, Sabah
4.2936
117.8725
Elevation
(m)
166
156
097
247
055
003
103
830
049
066
033
074
177
237
463
275
062
1.4.2 Strong Motion Stations
MMD also operates a total of 10 strong motion stations that has been installed in Klang
Valley area (Table 3 and Figure 6). The strong motion stations are located at Gohtong Jaya
(GTSM), Shah Alam (SASM), Bukit Kiara (BKSM), Dusun Tua (DTSM), Serendah
(SRSM), Ulu Yam (UYSM), Beranang (BRSM), Kundang (KNSM), Janda Baik (JBSM) and
Perbadanan Putrajaya (PYSM) and Wetland Putrajaya (PJSM).
Table 3. Detailed information of the strong motion stations in Klang valley area.
Station
Strong Motion Station Name
Latitude
Longitude Elevation
0
Code
( N)
(0E)
(m)
1
PYSM
Perbadanan Putrajaya
2.9180
101.6840
074
2
PJSM
Wetland Putrajaya
2.9683
101.6950
045
3
BKSM
Pusat Sains, Bukit Kiara
3.1467
101.6450
066
4
SASM
Bukit Cerakah, Shah Alam
3.0967
101.5117
028
5
UYSM
Empangan Batu, Ulu Yam
3.2717
101.6850
084
6
KNSM
Mardi Kundang, Kundang
3.2700
101.5150
027
7
SRSM
Pusat Serenti, Serendah
3.3650
101.6183
061
8
GTSM
Aminuddin Baki, Gohtong Jaya
3.3900
101.7750
844
9
JBSM
Pondok Polis, Janda Baik
3.3200
101.8633
577
10
DTSM
IKBN, Dusun Tua
3.1317
101.8400
067
11
BRSM
Kolej Mara, Beranang
2.9017
101.8633
073
No
8
Figure 6. Locations of strong motion stations in Klang Valley area. The colour is
indicating as ground elevation.
1.5 Hypocenter Determination Programs
1.5.1 Modified Joint Hypocenter Determination
The most fundamental parameters of an earthquake are the hypocenter (longitude, latitude
and depth) including the origin time. There are several methods for hypocenter determination.
Among them, the Joint Hypocenter Determination (JHD) method can determine hypocenters
of many earthquakes and station corrections simultaneously. However, sometimes the median
is very heterogeneous. Due to the trade-off between station corrections and focal depths of
earthquakes, the JHD method is unstable and unreliable. Thus, Hurukawa and Imoto [1992]
have introduced the Modified Joint Hypocenter Determination (MJHD) method. This method
can relocate many events and calculate the station corrections in order to remove the effects
of the lateral heterogeneity of the earth.
9
1.5.2 HYPOCENTER
HYPOCENTER version 3.2 (Lienert and Havskov, 1995) is a FORTRAN program for
locating local, regional and global earthquakes. The original version of this program was
described by Lienert, Berg and Frazer [1986], closely following the format of HYPO71 and
was programmed for locating local earthquakes (delta < 1000 km) due to the limitations of a
rectangular coordinate system and flat-earth layered velocity model. Therefore, this program
was modified by adapting the program to locate global as well as regional and local
earthquakes. The IASPEI91 software for calculating global travel times (Kennet and
Engdahl, 1991) had become available for making it possible to calculate the travel times
rather than interpolating tables.
1.6 Scope of Study Areas
The scope of study area covers four sub regions (R1, R2, R3 and R4) in Malay Peninsula as
shown in Figure 7. Each region is covering and associated with the local earthquakes that
occurred in 2009. Only the local events in 2009 are taken into consideration for analysis.
Figure 7. Scope of study areas (R1, R2, R3 and R4)
10
1.7 Purpose of Study
The purpose of this study is to relocate the hypocenter of the local earthquakes in Malay
Peninsula using the Modified Joint Hypocenter Determination (MJHD) and HYPOCENTER
programs. The revised hypocenter earthquake parameters determined by the programs are
then compared with the one obtained by the Antelope system. This study also will analyze the
hypocenter relocated parameters, striking direction and dipping of the nodal plane.
2.0 DATA
2.1 MiniSEED Data
We obtained the raw MiniSEED waveform data of local earthquakes in 2009 from the
National Seismic Network of Malaysia. The MiniSEED data is a stripped down version of
SEED data which contains waveform data without including the station and channel
metadata. This format of waveform data is used in Antelope V4.10 processing software for
analysis to determine the earthquake parameters.
2.2 Information Phases of the Local Earthquakes
Using the Antelope as processing software, the arrival times of P and S phases for 13 events
in 2009 are determined as described in Table 4, Table 5, Table 6 and Table 7. The S phase is
optional in this study and included for analysis when it is clearly seen in the horizontal
components.
Event
No.
1
Event
No.
1
Table 4. Information phases of Jerantut Earthquake
Date
Station
Arrival time (UTC)
Station channel
code
P
S
P
S
27-Mar-09
FRM
01:46:43.2 01:46:59.6
ELZ
HNN
27-Mar-09
KTM
01:46:49.9 01:47:9.20
HNN
HNN
27-Mar-09
IPM
01:46:51.3 01:47:17.3
HHZ
HNN
27-Mar-09
KGM 01:46:57.7 01:47:20.5
ELZ
HNN
27-Mar-09
KUM 01:47:0.30
HHZ
27-Mar-09
KOM 01:47:6.60 01:47:35.7
HHZ
HNN
Table 5. Information phases of the Manjong Earthquake
Date
Station
Arrival time (UTC)
Station channel
code
P
S
P
S
29-Apr-09
IPM
13:54:4.10 13:54:10.7
HHZ
HHZ
29-Apr-09
KUM 13:54:15.9 13:54:31.0
HHZ
HHZ
29-Apr-09
FRM
13:54:17.4 13:54:34.5
ELZ
ELZ
29-Apr-09
JRM
13:54:26.5
HHZ
-
11
Event
No.
1
2
3
4
5
6
7
Table 6. Information phases of the Bukit Tinggi earthquakes
Date
Station
Arrival time (UTC)
Station channel
code
P
S
P
S
07-Oct-09
JBSM 21:21:27.2 21:21:28.1
HNZ
HNE
07-Oct-09
GTSM 21:21:27.3
HNZ
07-Oct-09 UYSM 21:21:29.0
HNZ
07-Oct-09
SRSM 21:21:29.7 21:21:32.2
HNZ
HNN
07-Oct-09
FRM
21:21:30.0
ELZ
07-Oct-09
DTSM 21:21:30.2
HNZ
07-Oct-09
JRM
21:21:42.1
HHZ
07-Oct-09
IPM
21:21:52.5
HHZ
07-Oct-09
JBSM 21:26:07.7 21:26:08.7
HNZ
HNE
07-Oct-09
GTSM 21:26:07.9 21:26:08.8
HNZ
HNN
07-Oct-09 UYSM 21:26:11.5
HNZ
07-Oct-09
SRSM 21:26:12.7
HNZ
07-Oct-09
FRM
21:26:13.8
HNZ
07-Oct-09
JRM
21:26:18.9
HHZ
07-Oct-09
JBSM 21:51:12.2 21:51:13.1
HNZ
HNE
07-Oct-09
GTSM 21:51:12.3 21:51:13.2
HNZ
HNN
07-Oct-09
FRM
21:51:40.2
ELZ
07-Oct-09
JBSM 22:09:48.4 22:09:49.4
HNZ
HNE
07-Oct-09
GTSM 22:09:48.4 22:09:49.4
HNZ
HNE
07-Oct-09 UYSM 22:09:49.8 22:09:52.5
HNZ
HNN
07-Oct-09
SRSM 22:09:50.9 22:09:53.5
HNZ
HNN
07-Oct-09
JRM
22:10:01.3
HHZ
07-Oct-09
JBSM 22:21:01.0 22:21:02.0
HNZ
HNE
07-Oct-09
GTSM 22:21:01.1
HNZ
07-Oct-09 UYSM 22:21:02.9
HNZ
07-Oct-09
FRM
22:21:03.1
ELZ
07-Oct-09
SRSM 22:21:03.5
HNN
07-Oct-09 KNSM 22:21:03.6
HNZ
07-Oct-09
JRM
22:21:16.3
HHZ
08-Oct-09
JBSM 04:05:56.8 04:05:57.7
HNZ
HNE
08-Oct-09
GTSM 04:05:56.8 04:05:57.8
HNZ
HNE
08-Oct-09 UYSM 04:05:58.7
HNZ
08-Oct-09
SRSM 04:05:59.2
HNZ
08-Oct-09
FRM
04:05:59.9 04:06:02.9
ELZ
HNN
04-Dec-09 GTSM 04:41:46.9 01:41:47.9
HNZ
HNN
04-Dec-09 UYSM 01:41:48.6 01:41:50.8
HNZ
HNN
04-Dec-09
SRSM 01:41:49.3 01:41:51.5
HNZ
HNN
04-Dec-09 DTSM 01:41:49.8 01:41:52.7
HNZ
HNN
04-Dec-09
FRM
01:41:49.9 01:41:52.9
ELZ
ELE
04-Dec-09
JRM
01:42:01.7
HHZ
-
12
Event
No.
1
2
3
4
Table 7. Information phases of the Kuala Pilah earthquakes
Date
Station
Arrival time (UTC)
Station channel
code
P
S
P
S
29-Nov-09 BRSM 06:26:56.9 06:27:01.2
HNZ
HNE
29-Nov-09 DTSM 06:27:00.3
HNZ
29-Nov-09 UYSM 06:27:04.1
HNZ
29-Nov-09
FRM
06:27:04.3 06:27:13.6
ELZ
ELE
29-Nov-09 SRSM 06:27:05.9
HNZ
29-Nov-09
JRM
06:27:15.4
HHZ
29-Nov-09
KGM 06:27:18.4
ELZ
29-Nov-09
KOM 06:27:52.3
HHZ
29-Nov-09 BRSM 16:15:11.1 16:15:16.0
HNZ
HNE
29-Nov-09 UYSM 16:15:18.4
HNZ
29-Nov-09
FRM
16:15:18.6 16:15:27.9
ELZ
HNE
29-Nov-09 GTSM 16:15:19.5
HNZ
29-Nov-09 SRSM 16:15:20.4
HNZ
29-Nov-09 KNSM 16:15:20.5
HNZ
29-Nov-09
JRM
16:15:28.2
HHZ
29-Nov-09
KGM 16:15:31.1
ELZ
29-Nov-09
IPM
16:15:40.9
HHZ
29-Nov-09
KOM 16:15:41.1
HHZ
29-Nov-09
KUM 16:15:58.1
HHZ
30-Nov-09 BRSM 01:12:37.5 01:12:41.0
HNZ
HNE
30-Nov-09 DTSM 01:12:40.4 01:12:45.5
HNZ
HNE
30-Nov-09
FRM
01:12:43.0 01:12:52.2
HNZ
ELE
30-Nov-09 UYSM 01:12:43.8
HNZ
30-Nov-09 GTSM 01:12:44.7
HNZ
30-Nov-09 SRSM 01:12:45.8
HNZ
30-Nov-09
JRM
01:12:52.6 01:13:09.9
HHZ
BHE
30-Nov-09
KOM 01:13:04.8
HHZ
30-Nov-09
KGM 01:13:14.5 01:13:15.2
HNZ
HNE
30-Nov-09 BRSM 06:29:53.0 06:29:28.3
HNZ
HNE
30-Nov-09 DTSM 06:29:57.3
HNZ
30-Nov-09 UYSM 06:30:00.9 06:30:11.3
HNZ
HNN
30-Nov-09
FRM
06:30:01.4 06:30:10.5
ELZ
ELE
30-Nov-09 GTSM 06:30:02.1
HNZ
30-Nov-09 SRSM 06:30:03.3
HNZ
30-Nov-09
JRM
06:30:11.0
HHZ
30-Nov-09
KGM 06:30:13.9
ELZ
30-Nov-09
KOM 06:30:24.9
HHZ
-
13
2.3 Information Phases of the Southern Sumatra Earthquakes
The occurrence of the Southern Sumatra Earthquake on 30 September 2009 had created
temporary panic situations among the public in Malaysia due to the tremors being felt in
Malay Peninsula. According to the USGS, the intensity of the earthquake in the Malay
Peninsula is up to IV which meant that there are almost no structural damages to Malay
Peninsula (Figure 8). The arrival times of P and S phases for the mainshock and aftershocks
distribution of Southern Sumatra earthquakes (Figure 9) are determined using the MMD’s
Antelope processing software. The S phase is optional in this study and included for analysis
when it is clearly seen in the horizontal components. For the analysis, only local seismic
stations of the National Seismic Network of Malaysia are included. The detailed information
of the earthquake parameters and their phases is described in Table 8 and Table 9,
respectively.
Figure 8. USGS Community Internet Intensity Map of the Southern Sumatra,
Indonesia (USGS, 2009)
14
Figure 9. Epicentres distribution of the Southern Sumatra earthquakes. The colours
and circles are representing the categories of the hypocenter depth and magnitude,
respectively.
Table 8. Hypocenter parameters of the Southern Sumatra earthquakes.
Date
Origin Time
Longitude
Latitude
Depth
Mb/Mw
0
0
(UTC)
( E)
( S)
(km)
30 Sep 2009
10:16:10
99.7459
0.8733
91
Mw 7.5
30 Sep 2009
10:38:54
99.9309
0.8300
83
Mb 5.5
01 Oct 2009
01:52:31
101.6845
2.4898
25
Mb 6.2
01 Oct 2009
02:20:35
101.6820
2.3053
18
Mb 5.4
01 Oct 2009
03:17:10
101.7900
2.3264
40
Mb 4.6
01 Oct 2009
03:40:27
101.7670
2.2595
22
Mb 4.9
15
Table 9. Information phases of the Southern Sumatra earthquakes
Event
Date
Station
Arrival time (UTC)
Station channel
No.
code
P
S
P
S
1
30-Sep-09
FRM
10:17:15.4
ELZ
30-Sep-09
KGM
10:17:17.1
ELZ
30-Sep-09
KOM
10:17:21.4
HHZ
30-Sep-09
JRM
10:17:29.9
HHZ
30-Sep-09
IPM
10:17:30.0 10:18:31.1
HHZ
HHE
30-Sep-09
KUM
10:17:38.3 10:18:29.2
HHZ
HHN
30-Sep-09
KTM
10:17:50.0
ELZ
30-Sep-09
KSM
10:18:44.3
HHZ
30-Sep-09
SBM
10:19:12.2
HHZ
30-Sep-09
BTM
10:19:26.0
ELZ
30-Sep-09
BNM
10:19:35.1
HHZ
30-Sep-09
SPM
10:20:11.1
HHZ
30-Sep-09
KKM
10:20:13.0
HHZ
30-Sep-09
SDM
10:20:21.3
ELZ
30-Sep-09
KDM
10:20:23.0
ELZ
30-Sep-09
TSM
10:20:24.0
ELZ
30-Sep-09
LDM
10:20:34.1
HHZ
2
30-Sep-09
FRM
10:39:56.5
ELZ
30-Sep-09
KGM
10:39:57.0
ELZ
30-Sep-09
KOM
10:40:01.0
HHZ
30-Sep-09
JRM
10:40:10.0
HHZ
30-Sep-09
IPM
10:40:12.0 10:41:10.0
HHZ
HHE
30-Sep-09
KUM
10:40.21.0 10:41.27.2
HHZ
HHE
30-Sep-09
KTM
10:40:31.4
ELZ
30-Sep-09
KSM
10:41:22.0
HHZ
30-Sep-09
SBM
10:41:51.0
HHZ
30-Sep-09
BTM
10:42:10.5
ELZ
30-Sep-09
BNM
10:42:15.1
HHZ
30-Sep-09
SPM
10:42:52.5
HHZ
30-Sep-09
KKM
10:42:53.1
HHZ
30-Sep-09
SDM
10:43:01.4
ELZ
30-Sep-09
KDM
10:43:02.1
ELZ
30-Sep-09
TSM
10:43:04.0
ELZ
30-Sep-09
LDM
10:43:14.1
HHZ
3
01-Oct-09
KOM
01:53:41.4 01:55:00.1
HHZ
HHE
01-Oct-09
KGM
01:53:42.0
ELZ
01-Oct-09
FRM
01:53:55.0
ELZ
01-Oct-09
JRM
01:54:04.0 01:55:58.7
HHZ
HHN
01-Oct-09
IPM
01:54:13.1 01:56:08.0
HHZ
HHN
01-Oct-09
KUM
01:54:25.0 01:56:40.0
HHZ
HHN
01-Oct-09
KTM
01:54:25.4
ELZ
01-Oct-09
KSM
01:54:47.0
HHZ
01-Oct-09
SBM
01:55:18.1
HHZ
01-Oct-09
BTM
01:55:32.0
ELZ
16
4
5
6
01-Oct-09
01-Oct-09
01-Oct-09
01-Oct-09
01-Oct-09
01-Oct-09
01-Oct-09
01-Oct-09
01-Oct-09
01-Oct-09
01-Oct-09
01-Oct-09
01-Oct-09
01-Oct-09
01-Oct-09
01-Oct-09
01-Oct-09
01-Oct-09
01-Oct-09
01-Oct-09
01-Oct-09
01-Oct-09
01-Oct-09
01-Oct-09
01-Oct-09
01-Oct-09
01-Oct-09
01-Oct-09
01-Oct-09
01-Oct-09
01-Oct-09
01-Oct-09
01-Oct-09
01-Oct-09
01-Oct-09
01-Oct-09
01-Oct-09
01-Oct-09
01-Oct-09
01-Oct-09
BNM
SPM
KKM
SDM
TSM
KDM
LDM
KGM
KOM
FRM
JRM
IPM
KUM
KTM
SBM
BNM
SPM
KKM
SDM
TSM
KDM
LDM
KOM
KGM
FRM
JRM
IPM
KTM
KUM
BNM
SPM
KDM
LDM
KOM
KGM
FRM
JRM
IPM
KUM
KTM
01:55:43.0
01:56:22.
01:56:26.1
01:56:35.0
01:56:35.3
01:56:39.0
01:56:47.0
02:21:44.0
02:21:44.1
02:21:56.3
02:22:06.1
02:22:14.1
02:22:26.0
02:22:28.0
02:23:21.1
02:23:45.0
02:24:25.5
02:24:31.4
02:24:39.4
02:24:41.3
02:24:44.0
02:24:52.0
03:18:17.1
03:18:17.1
03:18:30.0
03:18:39.4
03:18:49.0
03:19:02.0
03:19:02.0
03:20:29.0
03:21:01.0
03:21:05.4
03:21:09.1
03:41:35.0
03:41:35.0
03:41:47.2
03:41:57.1
03:42:05.2
03:42:17.4
03:42:19.0
17
02:22:39.4
02:23:50.1
02:24:41.0
03:19:34.0
03:20:18.0
03:42:30.1
03:43:31.0
-
HHZ
HHZ
HHZ
ELZ
ELZ
ELZ
HHZ
ELZ
HHZ
ELZ
HHZ
HHZ
HHZ
ELZ
HHZ
HHZ
HHZ
HHZ
ELZ
ELZ
ELZ
HHZ
HHZ
ELZ
ELZ
HHZ
HHZ
ELZ
HHZ
HHZ
HHZ
ELZ
HHZ
HHZ
ELZ
ELZ
HHZ
HHZ
HHZ
ELZ
HHE
HHE
HHE
HHE
HHN
HHN
HHE
-
3. THEORY AND METHODOLOGY
3.1 Processing Software
Antelope is a software package for real-time seismic network data acquisition and processing.
It is a commercial software package with roots in the academic seismology community. This
study is using Antelope V4.10 which runs in UNIX environment on Sun Solaris as processing
software to determine the earthquake parameters such as origin time, hypocenter (e.g.
longitude, latitude, depth) and magnitude for an automatic and manual analysis. Antelope is
using Boulder Real Time Technologies (BRTT) software as commercial vendor for the
package which supports the collection, archiving, integration, and processing of environment
sensors, particularly seismic sensors.
3.1.1 Obtaining P and S Phases from the Antelope
We used the Antelope as processing software to read and display the MiniSEED data (Figure
10) and obtaining the P and S phases from the database archive of MMD (Figure 11). P is
primary wave and it moves in a compressional motion similar to the motion of a slinky, and
can be clearly seen in the vertical component (Z). Meanwhile, S is secondary wave and it
moves in a shear motion perpendicular to the direction the wave is travelling, and can be
clearly seen in the horizontal components (N-S or E-W).
Figure 10. The vertical component of the earthquake phase using the Antelope
processing software. P phase is denoted as red rectangular.
18
Figure 11. Obtaining the arrival time of P and S phases from the database at MMD
3.2 Verification of the Relocation Programs
In order to verify the hypocenter relocation of the local earthquakes, the MJHD and
HYPOCENTER programs were used. The phases of P and S of these earthquakes are taken
from the database archive of MMD (Table 9). We followed the directions of the nodal planes
as described by Hurukuwa [2009]. In order to increase a number of earthquakes, we included
the aftershocks of Southern Sumatra earthquakes. We analyzed the hypocenter relocation
using the MJHD and HYPOCENTER programs without considering the magnitude
calculation. Then, we compared the hypocenter parameters of the Southern Sumatra
earthquakes with the ones obtained by USGS and MJHD (Hurukawa, 2009). The predetermined results of the hypocenters relocated by USGS and MJHD method are shown in
Figure 12 (Hurukawa, 2009). Only local seismic stations of Malaysia are included for this
analysis. The uses of these stations for teleseismic events will enhance the capabilities of the
programs in determining the hypocenter parameters.
19
Figure 12. Hypocenters relocated by the MJHD method (upper figure) and USGS (lower
figure). Global CMT solution is also shown. Epicentres distribution and two vertical cross
sections along A-B and C-D lines, which are perpendicular to strikes of the two nodal planes,
are shown. Two nodal planes are shown by lines in cross sections. The nodal plane
corresponding to the fault plane is shown by a thick solid line in the A-B cross section. Note:
In order to increase a number of earthquakes, we included the Mw 6.6 Southern Sumatra
earthquake and its aftershock for relocation (Hurukawa, 2009).
20
3.3 Modified Joint Hypocenter Determination (MJHD)
In order to relocate hypocenter more accurately, this study is using the modified joint
hypocenter determination (MJHD) method developed by Hurukawa [2007]. According to
Hurukawa [1995], this technique allows us to relocate many events and station corrections
are calculated simultaneously in order to remove effects of the lateral heterogeneity of the
earth. The equation which is used in the determination of hypocenter is described as follows.
O  C ij  t ij  To j   Tij

t ij
x j
dx j 
t ij
y j
dy j 
t ij
z j
dz j  dTo j  dS i
(1)
where t ij and Tij are the arrival time and the calculated travel time of the j –th event at the i -th
station, respectively, dS i is the station correction at the i th station, To j is the origin time, O is
the observed travel time, C is the calculated travel time, O  C ij is the travel time residual
j th event at i th station, dx , dy , dz and dTo are correction of trial hypocenter of j th event.
The Joint Hypocenter Determination (JHD) solutions become unstable and unreliable
because of the trade-off between the station corrections and focal depths of earthquakes due
to the heterogeneous earth’s structure when the station coverage is less dense. Therefore,
Hurukawa and Imoto (1990, 1992) had modified this method by using the following
constraints.
n
S D
i 1
n
i
i
0
S
i
cos  i  0
S
i
sin  i  0
S
i
0
i 1
n
i 1
n
i 1
(2)
Here S i is the station correction at i th station, Di is the distance between the i th station and
the center of the region,  i is the azimuth of the i th station from the center of the region and
n is the number of stations.
3.3.1 Events and Stations Selection
We selected 13 events of local earthquakes that had occurred in Malay Peninsula for the
period of January to December 2009 and 6 events of the Southern Sumatra Earthquake (30
September until 1 October 2009). For the station selection, we used 17 weak motion (Table
2) and 10 strong motion (Table 3) stations which are located in Malay Peninsula. We used the
phase data of P-wave as described in Table 4, Table 5, Table 6, Table 7 and Table 9 as the
input data of the program (e.g. mjhd.data).
21
3.3.2 Focus Decision
Since the data quality is not so good, we applied a focus decision using the following
algorithm.
Repeat changing parameters
Iform:
1→ 0→ 0→ 0→ 0→ 0→ 0→ 0→ 0→ 0→ 0→ 0→ 0→ 0→ 0
Input files name:
prn1→ prn1→ prn2→ prn3→ prn4→ prn5→ prn6→ prn7→ prn8→
prn9→ prn10→ prn11→ prn12→ prn13→ prn14
Output files name:
out1→ out2→ out3→ out4→ out5→ out6→ out7→ out8→ out9→
out10→ out11→ out12→ out13→ out14→ out15
prn1→ prn2→ prn3→ prn4→ prn5→ prn6→ prn7→ prn8→ prn9→
prn10→ prn11→ prn12→ prn13→ prn14→ prn15
Max-res:
100→100→ 90→ 80→ 70 →60 →50 →40 →30 →20 →10 →5 →3
→2 →1
3.4 HYPOCENTER
HYPOCENTER is a FORTRAN program for locating local, regional and global earthquakes
(Lienert, 1986). This study is mainly focusing on the local earthquakes (delta < 1000 km)
due to the limitations of a rectangular coordinate system and flat-earth layered velocity
model. Since the structures of the crust and upper mantle beneath Malaysia are not precisely
studied, this study used IASPEI91 software for calculating global travel times (Kennet and
Engdahl, 1991) for P and S. The IASPEI91 model can be modified if so desired by changing
one of the included FORTRAN sources and regenerating the table files. The initial depth
guess is set to 0 km. The velocity model (Lienert, 1986) used for all local and regional events
is described in Table 10.
Table 10. Velocity model used for relocation (Lienert, 1986)
P-wave velocity (km/sec)
Depth to top of layer (km)
6.2
0.0
6.6
12.0
7.1
23.0
8.05
31.0
8.25
50.0
8.5
80.0
3.4.1 Events and Stations Selection
We selected the same events and stations as described in subsection 3.3.1. We used the phase
data of P and S waves as described in Table 4, Table 5, Table 6, Table 7 and Table 9 as the
input data of the program.
22
3.5 Digitising of Fault Lines
The major fault lines in Malay Peninsula can be digitised using Golden Software Surfer
[2004] to read the location of the fault lines in the coordinates of longitude and latitude
(Figure 13). The data of the fault lines map is taken from the Minerals and Geoscience
Department or JMG [2006]. Using this software, we digitised the Bukit Tinggi Fault, Kuala
Lumpur Fault, Lepar Fault and Seremban Fault Zone. Then, the fault lines data in XY
coordinates are plotted in the map using the Generic Mapping Tools option (Wessel and
Smith, 2007).
Figure 13. Digitising of fault lines using Golden Software Surfer [2004]. The red line is
indicated as digitised fault line in the coordinates of longitude and latitude.
23
4. RESULTS AND DISCUSSION
4.1 Verification of Programs with USGS
We verified the relocation programs of Antelope, MJHD and HYPOCENTER with USGS for
the case of Southern Sumatra earthquakes [2009]. However, the information phases of
Southern Sumatra earthquakes (Table 9) that are used for relocation are slightly different with
USGS parameters.
4.1.1 Antelope
The hypocenter parameters determined by the Antelope are well agreeing with the one
obtained by USGS. The detailed information of the earthquake parameters as described in
Table 8. The nodal plane is dipping toward SSE as shown by a thick solid line in Figure 14.
These phenomena had shown an interplate earthquake between the Australia Plate and the
Eurasia Plate.
Figure 14. Hypocenters located by the Antelope. Global CMT solution is also shown.
Epicenters distribution and two vertical cross sections along A-B and C-D lines,
which are perpendicular to strikes of the two nodal planes, are shown. Two nodal
planes are shown by lines in cross sections. The nodal plane corresponding to the fault
plane is shown by a thick solid line in the A-B cross section.
24
4.1.2 MJHD
The hypocentre parameters determined by the MJHD are almost agreeing with the ones
obtained by USGS [2009] and Hurukawa [2009]. Table 11 is describing the results for
hypocenter relocation by the MJHD method. The nodal plane is dipping toward SSE as
shown by a thick solid line in Figure 15. These phenomena had shown an intraplate
earthquake in the Australia Plate.
Table 11. Hypocentre relocation of the Southern Sumatra Earthquakes by MJHD
Date
Origin Time Longitude
Latitude
Depth
Mb/Mw
(UTC)
(0E)
(0S)
(km)
30-Sep-09
10:16:02
99.8153
0.7288
83
Mw 7.5
30-Sep-09
10:38:02
100.0051
0.6627
92
Mb 5.5
01-Oct-09
01:52:09
101.9738
1.9701
54
Mb 6.2
01-Oct-09
02:20:06
101.6493
2.0988
34
Mb 5.4
01-Oct-09
03:17:11
101.9832
1.7621
22
Mb 4.6
01-Oct-09
03:40:01
101.5863
2.3982
12
Mb 4.9
Figure 15. Hypocenters relocated by the MJHD. Global CMT solution is also shown.
Epicenters distribution and two vertical cross sections along A-B and C-D lines,
which are perpendicular to strikes of the two nodal planes, are shown. Two nodal
planes are shown by lines in cross sections. The nodal plane corresponding to the fault
plane is shown by a thick solid line in the A-B cross section.
25
4.1.3 HYPOCENTER
The hypocentre parameters of the Southern Sumatra earthquakes are well determined by the
HYPOCENTER program. Most of the hypocentre locations are located within the region.
However, the variation of the hypocenter depth is very large. Table 12 is describing the
results for hypocenter relocation by the HYPOCENTER method. The nodal plane is dipping
toward SSE as shown by a thick solid line in Figure 16. These phenomena had shown an
intraplate earthquake in the Eurasia Plate.
Table 12. Hypocentre relocation of the Southern Sumatra Earthquakes by HYPOCENTER
Date
Origin Time Longitude
Latitude
Depth
Mb/Mw
0
0
(UTC)
( E)
( S)
(km)
30-Sep-09
10:16:06
99.4870
1.3710
78
Mw 7.5
30-Sep-09
10:38:53
99.9320
1.1350
91
Mb 5.5
01-Oct-09
01:52:35
101.9730
2.3130
0
Mb 6.2
01-Oct-09
02:20:39
101.8500
2.0960
0
Mb 5.4
01-Oct-09
03:16:52
102.1040
3.8610
7
Mb 4.6
01-Oct-09
03:40:31
101.8250
2.0390
0
Mb 4.9
Figure 16. Hypocenters relocated by the HYPOCENTER. Global CMT solution is
also shown. Epicenters distribution and two vertical cross sections along A-B and CD lines, which are perpendicular to strikes of the two nodal planes, are shown. Two
nodal planes are shown by lines in cross sections. The nodal plane corresponding to
the fault plane is shown by a thick solid line in the A-B cross section.
26
4.2 Region 1 (R1) for Manjong Earthquake
The study area for R1 is located within Manjong district, Perak. The region between Latitude
3.800N to 4.500N and Longitude 100.400E to 101.100E was selected for hypocenter
determination. We analyzed only 1 event using 4 weak motion stations. The weak motion
stations are Ipoh, Kulim, FRIM and Jerantut. Since the fault system over this region was not
identified well (JMG, 2006), we assumed that the nodal planes of the fault line are along A-B
and C-D directions. Table 13 is describing the results for hypocenter relocation before
(Antelope) and after (MJHD and HYPOCENTER programs).
Before relocation as shown in Figure 17, the epicentre location was located over the
land with 3 km hypocenter depth. This epicentre was located within the Manjong district and
was verified based on the felt reports received by the department (e.g. BERNAMA, 2009).
Table 13. Hypocenter parameters before and after relocation process for Manjong Earthquake
Program
Date
OT
Long
Lat
Depth
Mb
(UTC)
(0E)
(0N)
(km)
Antelope
29-Apr-09
13:53:54.8 100.7290
4.1500
3.0
2.8
MJHD
29-Apr-09
13:53:23.8 100.6770
4.1123
0.0
2.8
HYPOCENTER
29-Apr-09
13:53:54.5 100.6640
4.0997
0.0
2.8
Figure 17. Hypocenter located by the Antelope processing software. The size of the
symbol represents the magnitude of the event. The colour and shape of the symbols
denoted the depth range of the event. A-B and C-D are cross section along and
perpendicular to the assumed fault, respectively.
However, after relocations the epicentre location are located near the offshore waters
of Perak (Figure 18 and Figure 19), and the hypocenter depth was constant at 0 km. The
epicentre distances relocated by the MJHD and HYPOCENTER programs are 7.1 km and 9.1
km (Chris, 1997), respectively from the revised parameters. The output results for the
27
relocation programs are described in Appendix-2, Appendix-3 and Appendix-4. Since, there
is only a single event occurred within this region and the location of the fault line was
undetermined. Therefore, the detail information of the nodal plane for this event was not
precisely resolved.
Figure 18. Hypocenter relocated by the MJHD program. Symbols are same as in
Figure 17.
Figure 19. Hypocenter relocated by the HYPOCENTER program. Symbols are same
as in Figure 17.
28
4.3 Region 2 (R2) for Jerantut Earthquake
The study area for R2 is located within Jerantut area, Pahang. The region for hypocenter
determination was selected between Latitude 3.500N to 4.200N and Longitude 102.200E to
102.900E. We used 6 weak motion stations to analyze the earthquake events. The weak
motion stations are Ipoh, Kulim, FRIM Kepong, Kuala Terengganu, Kluang and Kota Tinggi.
The cross section of the A-B and C-D are parallel and perpendicular to the Lepar Fault line,
respectively. Table 14 is describing the results for hypocenter relocation before (Antelope)
and after (MJHD and HYPOCENTER programs).
Before relocation, the epicentre location is located about 35 km from Lepar Fault with
hypocenter depth of 50 km (Figure 20). After relocation, the epicentre location which was
determined by the MJHD (Figure 21) was slightly north, and located 12.56 km from the
revised parameter which was determined by the Antelope processing software. However,
HYPOCENTER (Figure 22) result had shown that the epicentre location was located slightly
south, and located 15.14 km from the revised parameter. Both relocation programs had
determined that the hypocenter depth is 0 km. This described the characteristic of the strikeslip fault motion when occurred along the surface. However, the type of strike-slip fault was
unknown due to the limitation data for analysis.
Table 14. Hypocenter parameters before and after relocation process for Jerantut Earthquake
Program
Date
OT
Long
Lat
Depth
Mb
0
0
(UTC)
( E)
( N)
(km)
Antelope
27-Mac-09
01:46:25.5 102.5299
3.8721
50.0
3.2
MJHD
27-Mac-09
01:46:04.1 102.5080
3.9828
0.0
3.2
HYPOCENTER
27-Mac-09
01:46:29.0 102.4713
3.7493
0.0
3.2
Figure 20. Hypocenter located by the Antelope processing software. The size of the
symbol represents the magnitude of the event. The colour and shape of the symbols
denoted the depth range of the event. The cross sections of A-B and C-D are parallel
and perpendicular to the Lepar Fault, respectively.
29
As there was only a single earthquake event that had occurred within this region and
the epicentre location was located a few kilometres from the Lepar Fault, the dipping and
striking of the nodal plane for this event were not precisely resolved because of the
insufficient data and further analysis cannot be carried out.
Figure 21. Hypocenter relocated by the MJHD program. Symbols are same as in
Figure 20.
Figure 22. Hypocenter relocated by the HYPOCENTER program. Symbols are same
as in Figure 20.
30
4.4 Region 3 (R3) for Bukit Tinggi Earthquakes
The study area for R3 is located within Bukit Tinggi area, Pahang. The region for hypocenter
determination was selected between Latitude 3.100N to 3.700N and Longitude 101.400E to
102.100E. We used 3 weak motion and 6 strong motion stations to perform analysis of 7
events. The cross section of the A-B and C-D are perpendicular and parallel to the Bukit
Tinggi Fault line, respectively.
Before relocation, the epicentres of the earthquakes are rather scattered at the Bukit
Tinggi Fault line, and the hypocenter depths are varying from 1 to 3 km (Figure 23). We
cannot clarify the accurate hypocenter depth for these earthquakes. Table 15 is describing the
results for hypocenter relocation before (Antelope) and after (MJHD and HYPOCENTER
programs).
After relocation, the epicentres location which were determined by the MJHD are
scattered along the Bukit Tinggi Fault and Kuala Lumpur Fault (Figure 24), and the
hypocenter depth is varying between 6 to 30 km. Based on this result, we can see that the
Bukit Tinggi Fault is striking NW-SE directions and dipping toward NE. On the other hand,
the Kuala Lumpur Fault is striking NW-SE directions and dipping toward SW, and situated
just south of the Bukit Tinggi Fault. The NW-SE trending faults are commonly associated
with large quartz reefs along their length. However, HYPOCENTER results (Figure 25) had
shown that the epicentre locations are scattered at the Bukit Tinggi Fault line, and the
hypocenter depth is varying from 0 to 10 km. The nodal plane of Bukit Tinggi earthquakes
which was determined by HYPOCENTER is agreeing with the MJHD program.
Event
No.
1
2
3
4
5
6
7
Table 15. Hypocenter parameters for the Bukit Tinggi earthquakes
Program
Date
OT
Long
Lat
Depth
0
0
(UTC)
( E)
( N)
(km)
Antelope
07-Oct-09
21:21:26.0 101.8094 3.3495
2
MJHD
21:20:56.3 101.8040 3.1384 29.37
HYPOCENTER
21:21:26.4 101.8073 3.3345
0.0
Antelope
07-Oct-09
21:26:06.6 101.8215 3.3553
1
MJHD
21:26:29.7 101.8506 3.3704
6.47
HYPOCENTER
21:26:06.1 101.9073 3.4113
0.0
Antelope
07-Oct-09
21:51:11.1 101.8218 3.3538
3
MJHD
Undetermined – Insufficient data
HYPOCENTER
21:51:10.9 101.7943 3.3183
0.0
Antelope
07-Oct-09
22:09:47.1 101.8157 3.3518
2
MJHD
22:09:41.5 101.8191 3.3313 19.94
HYPOCENTER
22:09:46.5 101.8340 3.3438
10.0
Antelope
07-Oct-09
22:20:59.7 101.8135 3.3438
2
MJHD
22:19:56.6 101.8011 3.0498 27.08
HYPOCENTER
22:20:60.0 101.7967 3.3167
0.0
Antelope
08-Oct-09
04:05:55.6 101.8171 3.3486
3
MJHD
04:04:56.8 101.8770 3.1272
30.0
HYPOCENTER
04:05:55.5 101.8268 3.3677
4.2
Antelope
04-Dec-09
01:41:45.7 101.8054 3.3541
3
MJHD
01:40:53.4 101.8071 3.1413
29.6
HYPOCENTER
01:41:46.0 101.8057 3.3493
2.0
31
Mb
1.7
1.7
1.7
1.0
1.0
1.0
4.2
4.2
3.2
3.2
3.2
0.3
0.3
0.3
1.0
1.0
1.0
1.9
1.9
1.9
Figure 23. Hypocenters located by the Antelope processing software. The size of the
symbol represents the magnitude of the event. The colour and shape of the symbols
denoted the depth range of the event. Two vertical cross sections along C-D and A-B
lines, which are perpendicular to strikes of the nodal planes, are shown. The blue lines
are the Bukit Tinggi Fault and Kuala Lumpur Fault.
Figure 24. Hypocenters relocated by the MJHD program. Symbols are same as in
Figure 23.
32
Figure 25. Hypocenters relocated by the MJHD program. Symbols are same as in
Figure 23.
According to Hutchison and Tan [2009], the Bukit Tinggi Fault line is striking NWSE directions and mainly sinistral strike-slip with significant dip-slip components. Both
hypocenter relocation programs had demonstrated similar agreement that the nodal plane of
the Bukit Tinggi Fault is striking NW-SE directions and dipping toward NE. The type of the
fault is believed to be strike-slip fault with steep dip-slip components due to stress release as
the result of the great Andaman-Sumatran Earthquake [2004] (JMM and ASM, 2009).
When the data coverage provided is inadequate for analysis, the earthquake
hypocenter cannot be relocated by MJHD program, and may indeed be ignored without
sacrificing accuracy as happened for earthquake event number 3 in Table 15, In order to
remove the effects of lateral heterogeneity of the earth, the origin time determined by MJHD
is slightly faster than other programs because this program tries to minimize the travel times
between the observed and the calculated ones.
4.5 Region 4 (R4) for Kuala Pilah Earthquakes
The study area for R4 is located within Kuala Pilah area, Negeri Sembilan. The region for
hypocenter determination was selected between Latitude 2.400N to 3.100N and Longitude
101.800E to 102.500E. We used 6 weak motion and 6 strong motion stations to analyze 4
earthquake events. The cross sections of the A-B and C-D are parallel and perpendicular to
the Seremban Fault zone system, respectively. Table 16 is describing the results for
hypocenter relocation before (Antelope) and after (MJHD and HYPOCENTER programs).
Before relocation, the epicentres of the Kuala Pilah earthquakes are concentrated near
the connection point of Seremban Fault zone system, and the hypocenter depths are varying
from 3 to 15 km (Figure 26).
33
Event
No.
1
2
3
4
Table 16. Hypocenter parameters for the Kuala Pilah earthquakes
Program
Date
OT
Long
Lat
(UTC)
(0E)
(0N)
Antelope
29-Nov-09
06:26:51.6 102.0906 2.7398
MJHD
29-Nov-09
06:29:09.9 101.8785 2.6453
HYPOCENTER
29-Nov-09
06:29:52.2 102.0067 2.6737
Antelope
30-Nov-09
16:15:05.2 102.1169 2.7363
MJHD
30-Nov-09
16:15:00.9 101.9673 2.6530
HYPOCENTER
30-Nov-09
16:15:06.2 102.1202 2.7323
Antelope
30-Nov-09
01:12:30.0 102.1432 2.7382
MJHD
30-Nov-09
01:12:28.2 101.9047 2.6859
HYPOCENTER
30-Nov-09
01:12:30.4 101.9492 2.5812
Antelope
30-Nov-09
06:29:48.7 102.0665 2.7314
MJHD
30-Nov-09
06:29:00.4 102.0164 2.6890
HYPOCENTER
30-Nov-09
06:29:48.7 102.0810 2.6885
Depth
(km)
3.0
14.79
0.0
3.0
18.09
0.0
4.0
30.0
0.0
15.0
11.7
0.0
Mb
3.1
3.1
3.1
3.3
3.3
3.3
3.0
3.0
3.0
3.5
3.5
3.5
1
2
3
Figure 26. Hypocenter located by the Antelope processing software. The size of the
symbol represents the magnitude of the event. The colour and shape of the symbols
denoted the depth range of the event. Two vertical cross sections along A-B and C-D
lines, which are perpendicular to strikes of the nodal planes, are shown. The blue lines
are the Seremban faults zone.
The fault lines of Seremban Fault zone system were delineated as unnamed. It is
consists of 3 sub faults and labelled as 1, 2 and 3. After relocation, the nodal plane which was
determined by the MJHD (Figure 27) and HYPOCENTER (Figure 28) is striking SW-NE
and dipping toward S. The hypocenter depths which were relocated by the relocation
programs varied from 11 to 30 km and 0 km, respectively. However, HYPOCENTER
program was unable to determine the accurate hypocenter depth for the Kuala Pilah
34
earthquakes. The relocation programs had demonstrated 4 events occurring within this region
and the epicentre locations are following the curvilinear extension of fault line 2 of Seremban
Fault zone system.
1
2
3
Figure 27. Hypocenter relocated by the MJHD program. Symbols are same as in
Figure 26.
1
2
3
Figure 28. Hypocenter relocated by the HYPOCENTER program. Symbols are same
as in Figure 26.
35
4.6 Hypocenter Mapping of the Relocated Earthquakes
We mapped the hypocenter of the local earthquakes in Malay Peninsula based on the analysis
results obtained by the MJHD (Figure 29) and HYPOCENTER (Figure 30) programs and the
hypocenters were drawn using Generic Mapping Tools option (Wessel and Smith, 2007).
B
C
A
D
Figure 29. Epicentres distributions of the local earthquakes in Malay Peninsula [2009]
were relocated by MJHD program. The colour and circle are representing the depth
and magnitude of the earthquake, respectively. A, B, C and D are labelled as Lepar
Fault, Bukit Tinggi Fault, Kuala Lumpur Fault and Seremban Fault zone system,
respectively.
36
The significant difference between these two figures (Figure 29 and Figure 30) is that
an additional epicentre is observed at the Kuala Lumpur Fault line for the analysis using
MJHD program. It seemed to be that these epicentres at the Kuala Lumpur Fault line has also
been triggered due to stress release by the Southern Sumatra earthquakes [2009].
B
C
A
D
Figure 30. Epicentres distributions of the local earthquakes in Malay Peninsula [2009]
were relocated by HYPOCENTER program. The colour and circle are representing
the depth and magnitude of the earthquake, respectively. A, B, C and D are labelled as
Lepar Fault, Bukit Tinggi Fault, Kuala Lumpur Fault and Seremban Fault zone
system, respectively.
37
5. CONCLUSION
The collision of Indian Plate and Eurasian Plate had caused large strike-slip faults to form,
and resulting in the extrusion of crustal blocks towards the east and southeast in Southeast
Asia. This theory has suggested the existing of the major shear fault lines in Malay Peninsula.
A series of large earthquakes in recent years had changed the tectonic setting in the Southeast
Asia. The series of active seismic activities are believed to be preliminary indications of the
reactivation of major fault lines in Malay Peninsula.
This study used two complementary methods for hypocenter relocation namely
Modified Joint Hypocenter Determination or MJHD (Hurukawa, 2007) and HYPOCENTER
(Lienert, 1986) programs. The hypocentre parameters of the Southern Sumatra earthquakes
which were determined by the Antelope, MJHD and HYPOCENTER methods had been
verified with the one obtained by the USGS. Their results showed that the nodal plane is
dipping toward SSE and it is associated with an earthquake occurring in the subduction zone.
Since the results demonstrated are in close agreement with USGS and MJHD (Hurukawa,
2009), we are highly confident to use both relocation programs to determine the hypocenters
of local earthquakes in Malay Peninsula.
Each single event of Manjong and Jerantut Earthquake was precisely relocated by the
relocation programs. However, the detailed information of the nodal plane is not well
resolved because of the insufficient data for analysis. For Manjong Earthquake, the
hypocenter relocation programs had shown the epicentre was located near the offshore waters
of Perak. Meanwhile, the Jerantut Earthquake was located slightly north and south from the
revised parameter by the MJHD and HYPOCENTER programs, respectively. According to
Hutchison and Tan [2009], the metasediments along the Lepar Fault have been sheared into
phyllonites that show sub-horizontal to horizontal striations indicating sinistral strike-slip
movement, resulting from E-W compression.
Before relocation, the epicentres of the Bukit Tinggi earthquakes are rather scattered
at the Bukit Tinggi Fault line and the accurate hypocenter depth was not well determined.
After relocation by MJHD, the epicentres were scattered along the Bukit Tinggi Fault and
Kuala Lumpur Fault lines, and the hypocenter depth varies from 6 to 30 km. These results
showed that the nodal plane of the Bukit Tinggi Fault line is striking NW-SE directions and
dipping toward NE. Meanwhile, the nodal plane of the Kuala Lumpur Fault is striking NWSE directions and dipping toward SW. However, HYPOCENTER program showed that the
epicentre locations were scattered within the Bukit Tinggi Fault line and the hypocenter depth
varies from 0 to 10 km. The nodal planes of Bukit Tinggi Fault line which were determined
by the relocation programs had a similar agreement. When the data coverage provided is
inadequate for analysis, the earthquake hypocenter cannot be relocated by MHJD program
(e.g. earthquake event number 3 in Table 15). In order to remove the effects of lateral
heterogeneity of the earth, the origin time determined by the MJHD is slightly faster than
other programs because this program tried to minimize the travel time differences between
the observed and the calculated ones.
Hypocenter parameters for Kuala Pilah earthquakes were precisely determined by the
hypocenter relocation programs. Before relocation, the epicentres are concentrated near the
Seremban fault zone system. However, after relocation the nodal plane was striking SW-NE
directions and dipping toward S, and following the curvilinear extension of fault line 2 of
Seremban fault zone system.
Our study demonstrated that hypocenter locations were dramatically improved by
using the MJHD and HYPOCENTER methods. These methods will be quite effective in
determining hypocenters of local earthquakes in Malay Peninsula.
38
FUTURE PLAN
As part of our study on hypocenter relocation of the local earthquakes in Malay Peninsula, we
would like to extend our study on focal mechanism determination. The focal mechanism of
the local earthquakes can be determined using the first motion of P-wave and moment tensor
inversion analysis. We would like to study more on Peak Ground Acceleration or PGA for
strong motion analysis to estimate the g-value of the local earthquake in Malay Peninsula.
The g-value analysis becomes very important in the recent year due to the tremors being felt
in Malaysia. The g-value analysis may help us to build a new standard code for buildings in
Malaysia.
ACKNOWLEDGEMENT
Special thanks to Dr. Nobuo Hurukawa (Director of International Institute of Seismology and
Earthquake Engineering, IISEE) for kindly providing us the MJHD program.
39
APPENDICES
Appendix-1
Figure A-1-1. Distribution of continental blocks, fragments and terranes, and principal
sutures of Southeast Asia. Numbered microcontinental blocks: 1. Hainan Island terranes, 2.
Sikuleh, 3. Paternoster, 4. Mangkalihat, 5. West Sulawesi, 6. Semitau, 7. Luconia, 8. Kelabit
Longbowan, 9. Spratley Islands– Dangerous Ground, 10. Reed Bank, 11. North Palawan, 12.
Paracel Islands, 13. Macclesfield Bank, 14. East Sulawesi, 15. Bangai–Sula, 16. Buton, 17.
Obi–Bacan, 18. Buru–Seram, 19. West Irian Jaya. C–M=Changning–Menglian Suture
(Metcalfe, 2006).
40
Appendix-2
Output result of the first iteration for Manjong Earthquake using the MJHD program
**********************************************************
*
*
*
Modified Joint Hypocenter Determination (MJHD)
*
*
*
*
for Teleseismic Event
*
*
*
*
with Two Priors
*
*
*
**********************************************************
X0,Y0 =
100.729
slope =
0.000 0.000 0.000
If these are not zero, the centroid will change.
AST
1
2
3
4
1
0
1
2
3
4
5
6
7
8
9
10
NO
AST
DAMP
12172.6182
1.9371
1.9371
1.9371
1.9371
1.9371
1.9371
1.9371
1.9371
1.9371
1.9371
M D
P,SEC
1
MEQ= 1
NCOL= 9
SSR
Y
9
ZST
0.5000
1.0000
1.0000
1.0000
1.0000
1.0000
1.0000
1.0000
1.0000
1.0000
1.0000
SEC
DT
D,DEG
0.097
0.247
0.074
0.055
1 JRM
1
MNST= 3
d
az
0.000
0.000
0.000
0.000
ress= 100.0
1.282 135.228
0.441 42.081
1.135 355.987
1.763 98.470
STD1= 999.00
AIC
0.6143411E+02
0.2645114E+02
0.2645114E+02
0.2645114E+02
0.2645114E+02
0.2645114E+02
0.2645114E+02
0.2645114E+02
0.2645114E+02
0.2645114E+02
0.2645114E+02
HMN
429 1353 34.50
1.01
9.30
0.50
21.10
1.17
22.60
1.29
31.70
1.81
PHC
3.23330
4.47950
5.29020
3.88670
1 KUM
NST= 4
NROW= 5
ITR
YST
101.63330
101.02550
100.64920
102.47670
1 IPM
NEQ=
IPM
KUM
FRM
JRM
XST
FRM
IPM
KUM
JRM
FRM
4.150
X
DX
O-C
Y
DY
Z
DZ
MAG
N
STD
0.00
7.20
2.8
4
0.804
AZIM
100.677
4.112
0.081
0.039
0.78
43.60
-0.19
358.64
-1.04
132.42
0.46
97.05
41
STN
1
2
3
4
FRM
IPM
KUM
JRM
SUM=
PSC
DSC
0.000
0.000
0.000
0.000
0.000
MEAN
32.804
52.394
24.608
60.590
STD
-1.044
0.777
-0.189
0.456
0.000
42
N
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
NEQ=
1
1
1
1
1
Appendix-3
Output result of the second iteration for Manjong Earthquake using the MJHD program
**********************************************************
*
*
*
Modified Joint Hypocenter Determination (MJHD)
*
*
*
*
for Teleseismic Event
*
*
*
*
with Two Priors
*
*
*
**********************************************************
X0,Y0 =
100.729
slope =
1
2
3
4
XST
101.63330
101.02550
100.64920
102.47670
YST
3.23330
4.47950
5.29020
3.88670
1
KUM
1
MEQ= 1
NCOL= 9
MNST=
1 IPM
NEQ=
ITR
0
1
2
3
4
5
6
7
8
9
10
NO
AST
1
NST= 4
NROW= 5
SSR
12172.6182
1.9371
1.9371
1.9371
1.9371
1.9371
1.9371
1.9371
1.9371
1.9371
1.9371
Y
M D
P,SEC
1
IPM
KUM
FRM
JRM
0.000 0.000 0.000
If these are not zero, the centroid will change.
AST
FRM
IPM
KUM
JRM
FRM
9
4.150
DAMP
0.5000
1.0000
1.0000
1.0000
1.0000
1.0000
1.0000
1.0000
1.0000
1.0000
1.0000
SEC
DT
D,DEG
JRM
3
PHC
0.000
0.000
0.000
0.000
d
1.282
0.441
1.135
1.763
az
135.228
42.081
355.987
98.470
1
ress= 100.0
STD1= 999.00
AIC
0.6143411E+02
0.2645114E+02
0.2645114E+02
0.2645114E+02
0.2645114E+02
0.2645114E+02
0.2645114E+02
0.2645114E+02
0.2645114E+02
0.2645114E+02
0.2645114E+02
HMN
429 1353 34.50
1.01
9.30
0.50
21.10
1.17
22.60
1.29
31.70
1.81
ZST
0.097
0.247
0.074
0.055
X
DX
O-C
Y
DY
Z
DZ
MAG
N
STD
0.00
7.20
2.8
4
0.804
AZIM
100.677
4.112
0.081
0.039
0.78
43.60
-0.19
358.64
-1.04
132.42
0.46
97.05
43
1
2
3
4
STN
FRM
IPM
KUM
JRM
SUM=
PSC
0.000
0.000
0.000
0.000
0.000
DSC
32.804
52.394
24.608
60.590
MEAN
-1.044
0.777
-0.189
0.456
0.000
44
STD
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
NEQ=
1
N
1
1
1
1
Appendix-4
Output results for the Manjong Earthquake using HYPOCENTER program
Input File: NIEDD1.DAT
Reset
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test(
test(
test(
test(
test(
test(
test(
test(
test(
test(
test(
test(
test(
test(
test(
test(
test(
test(
test(
test(
test(
test(
test(
test(
test(
test(
test(
test(
test(
test(
2)= 500.0000
7)=
-3.0000
8)=
2.6000
9)=
0.0010
11)=
99.0000
13)=
20.0000
31)=
3.0000
34)=
0.5000
35)=
3.0000
36)=10000.0000
38)=
0.0000
40)=
0.0000
41)=20000.0000
51)=
3.6000
52)=
10.0000
50)=
1.0000
56)=
1.0000
60)=
10.0000
61)=
0.0000
62)=
1.0000
63)=
0.0000
64)=
2.0000
65)=
3.0000
66)=
0.0000
67)=
0.0000
69)= 110.0000
71)=
1.0000
72)=
0.0000
74)=
0.0000
79)=
1.0000
IPM
KUM
FRM
JRM
428.770N101 1.530E
517.410N10038.950E
314.000N10138.000E
353.200N10228.600E
247
74
97
55
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
--------- HYPOCENTER Version 4.0
1998 -----------
Maximum elev. station: IPM 428.77N 101 1.53E
Trial depth = 0.00 Vp/Vs = 1.74
Velocity Model
Depth, km
0.00
12.00
23.00
31.00
50.00
80.00
Vp, km/s
6.20
6.60
7.10
8.05
8.25
8.50
Vs, km/s
3.56
3.79
4.08
4.63
4.74
4.89
N
45
elevation = 247 m
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test(
test(
test(
test(
test(
test(
test(
test(
test(
test(
test(
test(
test(
test(
test(
test(
test(
test(
test(
test(
test(
test(
test(
test(
test(
test(
test(
test(
test(
test(
2)= 500.0000
7)=
-3.0000
8)=
2.6000
9)=
0.0010
11)=
99.0000
13)=
20.0000
31)=
3.0000
34)=
0.5000
35)=
3.0000
36)=10000.0000
38)=
0.0000
40)=
0.0000
41)=20000.0000
51)=
3.6000
52)=
10.0000
50)=
1.0000
56)=
1.0000
60)=
10.0000
61)=
0.0000
62)=
1.0000
63)=
0.0000
64)=
2.0000
65)=
3.0000
66)=
0.0000
67)=
0.0000
69)= 110.0000
71)=
1.0000
72)=
0.0000
74)=
0.0000
79)=
1.0000
IPM
KUM
FRM
JRM
428.770N101 1.530E
517.410N10038.950E
314.000N10138.000E
353.200N10228.600E
247
74
97
55
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
--------- HYPOCENTER Version 4.0
Maximum elev. station: IPM
Trial depth = 0.00
1998 -----------
428.77N 101 1.53E
elevation =
247 m
Vp/Vs = 1.74
Velocity Model
Depth, km
0.00
12.00
23.00
31.00
50.00
80.00
EVENT #
Vp, km/s
6.20
6.60
7.10
8.05
8.25
8.50
Vs, km/s
3.56
3.79
4.08
4.63
4.74
4.89
N
1
2009 0429 1353 54.80D
4.1500 102.729 03.0
Consistency check performed
46
004
2.8BMMD 2.5LMMD
1
First arrival: IPM
2009
429
13 54
4.10
Starting location depth = 0.0 km
Starting location .15 km from closest station: 4.53
rms = 5.56
maximum multi-station phase: P
101.10
4
Regression azimuth= -109.1 Apparent velocity= 9.04 km/s
delta = 1.0 R2 = 0.61
3 multiple-phase stations
IPM
KUM
FRM
P -S
P -S
P -S
71.8 km
164.3 km
186.0 km
Starting location from 2 distances: 4.10
rms = 8.51
Starting location from 2 distances: 3.81
rms = 6.72
iter
origin
lat
long depth
(sec) (dg mn)
(dg mn) (km)
1
54.72 350.06N 10056.81E
0.0
2
51.39 357.80N 10027.38E
0.0
3
54.58 4 6.13N 10040.30E
0.0
4
54.47 4 5.98N 10039.86E
0.0
4
54.48 4 5.98N 10039.86E
0.0
depth freed: icd= 3
no
m
7
7
7
7
7
2
2
2
2
2
101.57
100.95
rms
(sec)
6.48
1.84
0.50
0.50
0.50
date hrmn
sec lat
long
depth no m
9 429 1353 54.48 4 5.98N 100 39.9E 0.0 7 3
damp.
0.005
0.005
0.005
0.005
0.005
erlg
(km)
0.0
115.5
35.4
14.7
14.7
erlt
(km)
0.0
60.7
16.2
7.3
7.3
erdp
(km)
0.0
0.0
0.0
0.0
0.0
rms damp erln erlt erdp
0.50 0.000 17.7 16.8 62.9
ic
7
Origin time error: 2.90
DRMS Values: d= 20.00 km
DRMS:
DRMS pos
lon+d
1.15
lon-d
0.96
lat+d
2.18
lat-d
2.61
depth+d
0.75
depth-d
0.00
Resolution matrix: k = 0.005
Long
Lat
Depth
Long
0.993
-0.004
0.000
Lat
-0.004
0.975
-0.021
Depth
0.000
-0.021
0.976
Azimuthal Gap in Station Coverage 228 degrees
stn
IPM
IPM
KUM
KUM
FRM
FRM
JRM
dist
58
58
132
132
144
144
203
azm
43.7
43.7
359.3
359.3
131.6
131.6
96.6
ain
90.2
90.2
90.0
90.0
70.0
70.0
50.4
w
0
0
0
0
0
0
0
phas
P
S
P
S
P
S
P
calcphs
PG
SG
PG
SG
PN2
SN2
PN4
hrmn
1354
1354
1354
1354
1354
1354
1354
47
tsec
4.1
10.7
15.9
31.0
17.4
34.5
26.5
t-obs
9.6
16.2
21.4
36.5
22.9
40.0
32.0
t-cal
9.4
16.3
21.2
36.9
23.2
40.3
30.6
res
0.26
-0.07
0.19
-0.42
-0.24
-0.28
1.41
wt di
0.99* 1
1.00*34
1.00*15
0.96*17
0.99*12
0.98*20
0.61* 1
Difference from previous solution:
dorigin= -0.3 sec dx= -229.0 km dy= -5.6 km dz= -3.0 km drms= 0.10
unweighted rms = 0.59
--------------------------------------------------------------------------average differences from previous solutions: 1 events
origin time:
longitude:
latitude:
depth:
mean
-0.3 sec
-229.0 km
-5.6 km
-3.0 km
rms
0.0
0.0
0.0
0.0
average station residuals (weighted):
station
IPM
KUM
FRM
JRM
p residual rms dev
0.26
0.00
0.19
0.00
-0.24
0.00
1.41
0.00
Mean rms value (
no p
1
1
1
1
s residual rms dev
-0.07
0.00
-0.42
0.00
-0.28
0.00
1 events) =
48
0.499
no s
1
1
1
REFERENCES
Balendra, T., Lam, N.T.K., Wilson, J.L., and Kong, K.H., (2001) Analysis of long-distance
earthquake tremors and base-shear for buildings in Singapore, Journal of Engineering
Structures 2001: Vol 24, pp 99-108, 2001.
BERNAMA, 2009, Mild Tremor Detected in Manjong, Perak, released on 30 April 2009.
Briais, A., Patriat, P., and Tapponnier, P., 1993, Updated interpretation of magnetic
anomalies and seafloor spreading stages in the South China Sea: implications for the
Tertiary tectonics of Southeast Asia. Journal of Geophysical Research 98: 6299-6328
Chris, M., 1997, Latitude/Longitude Distance Calculation, website
http://jan.ucc.nau.edu/~cvm/latlongdist.html.
Hutchison, C., S., and Tan, N., K., 2009, Geology of Peninsula Malaysia, Department of
Geology, University of Malaysia.
Golden Software Surfer version 8.05, 2004, released on 11 May 2004, Golden Software Inc.
Harbury et al., 1990, “Structural evolution of Mesozoic Peninsular Malaysia”, Journal of the
Geological Society; February 1990; v. 147; no. 1; p. 11-26; DOI:
10.1144/gsjgs.147.1.0011 © 1990 Geological Society of London.
Hurukawa, N., and Imoto, M., 1990, Fine structure of an underground boundary between the
Philippine Sea and Pacific plates beneath the Kanto district, Japan, Zisin (J. Seismol. Soc.
Jpn.), 43, 413-429.
Hurukawa, N., and Imoto, M., 1992, Subducting oceanic crust of the Philippine Sea and
Pacific plates and weak-zone-normal compression in Kanto district, Japan. Geophysics
Journal Int., 109, 639-652.
Hurukawa, N., 1995, Quick aftershock relocation of the 1994 Shikotan earthquake and its
fault planes. Geophy. Res. Letters, Vol. 22, No. 23, pp 3159-3162.
Hurukawa, N., 2007, Program for Modified Joint Hypocenter Determination (received via
email on 26 October 2009).
Hurukawa, N., 2009, “Aftershock Distribution and the Mainshock Fault Plane by MJHD
method: Application to September 30, 2009 Southern Sumatra Earthquake”, International
Institute of Seismology and Earthquake Engineering, Building Research Institute, Japan.
Metcalfe, I., 2006, Palaeozoic and Mesozoic Tectonic Evolution and Palaeogeography of
East Asian Crustal Fragments: The Korean Peninsula in context. Gondwana Research 9,
24-46.
MMD, 2010, Data recorded by the Geophysics and Tsunami Division, Malaysian
Meteorological Department, last reviewed on 30 Mac 2010.
JMM and ASM, 2009, “Seismic and Tsunami Hazards and Risks Study in Malaysia”, Final
Report, 1-200.
Kennett, B. L. N., and E. R. Engdahl, 1991, Travel times for global earthquake location and
phase identification. Geophysical Journal International 122, 429–465.
Lienert, B., R., E., Bery and Frazer, L., N., 1986, HYPOCENTER: An earthquake location
method using centered, scaled, and adaptively least squares, Bull. Seism. Soc. Am., 76,
771-783.
Lienert, B., R., and Havskov, 1995, A computer program for locating earthquakes both
locally and globally, Seism. Res. Lett., 66, 26-36.
JMG (Minerals and Geoscience Department), 2006, “Seismotectonic of Malaysia”, Third
Edition 2006, Malaysia.
Tapponnier, P., Peltzer, G., GAY, L., D., Armijo, R., and Cobbold, P., R., 1982, Propagating
Extrusion Tectonics in Asia: New Insights from Simple Experiments with Plasticine.
Geology 10: 611–616.
49
Tjia., H., D., 2008, Earthquake and Tsunami Risks in Continental Southeast Asia, 2nd
International Round Table 2008, Kota Kinabalu, Sabah.
Tjia., H., D., 2009, Recognising Active Geological Structures, Training Workshop in
Engineering Seismology, Malaysian Meteorological Department, Petaling Jaya, Selangor,
Malaysia.
Peltzer, G., and Tapponnier, P., 1988, Formation and evolution of strike-slip faults, rifts, and
basins during the India-Asia Collision: an experimental approach. Journal of Geophysical
Research 93: 15085-1511.
USGS, 2009, last accessed on 2 April 2010, website:
http://earthquake.usgs.gov/earthquakes/dyfi/events/us/2009mebz/us/index.html.
Wessel, P., and Smith, W., H., F., 2007, “The Generic Mapping Tools, version 4.2.0”
http://gmt.soest.hawaii.edu/gmt/doc/pdf/GMT_Tutorial.pdf.
50