Modern Seismic Hazard With 2009 Quake

VIETNAM

Seismic Hazard of Western Indonesia

PHILIPPINES

Seismic Hazard

Ho Chi Minh City

Pan a y

Long XuyenMy Tho Rach GiaCan Tho

110°

115°

Banda Aceh

Pinang

5°

T

10°

INDIAN OCEAN

2006

2006

2006

SU

EXPLANATION

Fatal Earthquakes Sep 2007 M8.5

ND

A (J AVA ) TREN CH

Magnitude

5 - 5.9 6 - 6.9 7 - 7.9 8-9

Depth for 1988-June 2009 events 1 - 64 km 65 - 299 ≥ 300

Faults

Subduction Transform

Active Volcanoes

DISCLAIMER Base map data, such as place names and political boundaries, are the best available but may not be current or may contain inaccuracies and therefore should not be regarded as having official significance.

400

Scale 1:7,500,000

800

Lo mp o c

Su m ba w a 10°

1994

1994

65 mm/yr 115°

1,200 Kilometers

DISCUSSION The tectonics of the poster region are dominated by the subduction of the Australia plate beneath the Sunda plate. The rate of relative plate motion varies from east to west across the map region, as indicated in the large map. Interplate earthquakes occur as the result of seismic slip on the thrust boundary between the overriding Sunda plate and the subducting Australia plate. The Sumatran fault accommodates a large component of trench parallel motion of the western Australia/Sunda plate boundary that is not be accommodated by slip on the thrust-fault interface between the two plates. Intraplate shocks within the Australia or Sunda plate reflect stresses generated in those two plates by the overall subduction process. The large map shows epicenters of magnitude 5 and larger earthquakes occurring in the region from the beginning of 1988 through February 2008. Main shocks of magnitude 7.7 and larger and aftershocks occurring within 31 days of the main shocks are represented by differently colored symbols. The large map also shows earthquakes for which fatalities are listed in the Preliminary Determination of Epicenters publication of the U. S. Geological Survey. For some earthquakes, casualties were the result of building damage due to shaking. For other earthquakes, casualties were the result of inundation by tsunami generated by the earthquakes. Several earthquakes produced casualties from both building damage and tsunami inundation. In a few cases, fatalities resulted from fright at the occurrence of relatively minor shaking. The magnitude 7.5 earthquake of August 8, 2007, with an epicenter close to Jakarta and a focal depth of 290 km, did not produce fatalities, but it is labeled because it was widely felt.

Fatal Earthquakes 1988 - 2008 Year Mo Dy Hr Mn Lat Flo res 1990 11 1991 5 1994 2 1994 6 Su m ba 10 1995 1998 9 1999 12 2000 6 2000 6 2000 6 2002 11 2004 1 2004 2 2004 9 2004 12 2005 2 2005 3 2006 5 2006 7 2006 12 2007 3 2007 3 2007 9 2007 9 2008 2

15 26 15 2 6 28 21 4 5 7 2 1 16 15 26 2 28 26 17 17 6 6 12 12 20

2 10 17 18 18 13 14 16 23 23 1 20 14 8 0 5 16 22 8 21 3 5 11 23 8

TIMOR116.652 104.255 PLATE112.934 101.45

34 3.939 59 5.858 7 -4.999 17 -10.409 9 -2.007 34 -8.177 14 -6.823 28 -4.76 55 -4.151 45 -4.651 26 2.837 59 -8.349 44 -0.516 35 -8.784 58 3.287 55 -7.004 9 2.069 53 -7.961 19 -9.254 39 0.626 49 -0.512 49 -0.488 10 -4.52 49 -2.506 8 2.778

97.405

112.34 105.498 102.031 101.953 101.848 96.088 115.758 100.548 115.325 95.972 107.816 97.097 110.446 107.411 99.859 100.524 100.53 101.374 100.906 95.978

Dep 30 49 23 35 37 152 42 34 47 32 30 45 13 97 30 57 22 12 34 30 19 11 34 30 35

Mag 6.7 5.1 6.8 7.8 6.7 6.5 6.4 7.9 5.5 6.7 7.2 5.8 5 5.3 9 4.8 8.6 6.4 7.7 5.8 6.4 6.3 8.5 7.9 7.4

Bird, P., 2003, An updated digital model of plate boundaries: Geochem. Geophys. Geosyst., v. 4, no. 3, pp. 1027- 80. McCaffrey,Robert, 2009; The tectonic framework of the Sumatran subduction zone: Annual Review of Earth and Planetary Sciences; V. 37, P. 345-366. NIMA and ESRI, Digital Chart of the World NOAA GEBCO and GLOBE Elevation Models

60

0

>

-3

5

25

-2

0

0

7 1 207 277* 84 1 5 103 1 1 3 1 5 1 227898* 1 1303 5749 665* 7 67 ** 25 ** 3

Scale 1:10,000,000 250

115°

500 Kilometers

Ho Chi Minh City

2004 area outside of EERI paper extent

Significant rupture zones along offshore western Sumatra: 1797, 1833, and 2000 - 2008

Deaths

* most deaths are from tsunamis ** casualties for earthquakes on same day are listed with the first

DATA SOURCES USGS, National Earthquake Information Center IASPEI, Centennial Catalog (1900 - 1999) and extensions (Engdahl, E.R. and Villaseñor, A., 2002, Global Seismicity: 1900 - 1999, chap. 41 of Lee, W.H.K., and others,eds., International Earthquake and Engineering Seismology, Part A: New York, N.Y., Elsevier Academeic Press, 932 p.) HDF (unpublished earthquake catalog) (Engdahl, 2003)

20

-2

5

15

-1

0

10

-1

-9

9

8

-8

7

-6

5

-5

4

Lon

110°

95°

100°

5°

105°

5°

Much of the thrust-fault plate boundary offshore of Sumatra has ruptured in a sequence of great earthquakes since 2000. Although the effect of these earthquakes is to reduce stress on much of the thrustfault boundary, continuing readjustments of stress and associated aftershocks are expected around the edges of the rupture zones (solid colors on map). In addition, some sections of the thrust-fault boundary offshore of central and southern Sumatra have not ruptured in the recent sequence of great earthquakes and retain the potential to produce one or more earthquakes of magnitude 8 or greater in upcoming years or decades. This section of the Australia/Sunda plate boundary produced earthquakes of magnitude larger than 8.5 in 1797 and 1833 (rupture zones dashed on map), and geodetic and geologic observations imply that much of the elastic strain that accumulated on the plate boundary since the early 19th century has not yet been released in the shocks that have occurred in the region since 2000. The exact timing of future earthquakes cannot be specified. Rupture Zones from Rich Briggs, "2007 Sumatra, Indonesia, Earthquakes, " EERI Newsletter, Oct 2007, V 41, N 10.

Medan

2004

Discussion of Rupture Zones

IA

1988-June 2009 M ≥ 5

The broad red vectors represents the motion of the Australia Plate relative to the Sunda Plate in the region. The motion of the Australia Plate is generally 50-66 mm/yr northward with respect to the Sunda Plate in the southern region, but diminishes to 40-50 mm/yr towards the north.

200

2004

105°

YS

Jun 1994 M7.8

0

110°

1998

100°

LA

Jun 2000 M7.9

105°

Bal i 2004 2004

Mataram

A

Mar 2005 M8.6 100° Co co s I s. (Au sRELATIVE tra lia ) PLATE MOTIONS

Surabaya

Surabaya

M

Jul 2006 M7.7

95°

Ja va

-4

Semarang

Yogyakarta

55 mm/yr

BANDA SEA PLATE

Les ser S u n da I sla n d s

2005 Bandung

Yogyakarta

10°

Seismic Hazard expressed as Peak Ground Acceleration (%g) with a 10% probability of exceedance in 50 years. Reference site condition is firm rock. From USGS/AID Administrative Report.

3

Great er S u nd a Is la n ds

Semarang

Java

95°

5°

-3

Tanjungkarang-Telukbetung 2007 M 7.5 Jakarta

2

1994

1999

Dec 2004 M9

Bandjermasin

.

-2

2007 2000 2000

Bandung

INDIAN OCEAN

5°

Greater Sunda Islands

Jakarta

-7

-2.602° S., 101.702° E. Depth 10 km Mw = 6.6 (USGS)

Su la w esi

Bengkulu 2000

2000

10°

Palangkaraya

MOLUCCA SEA PLATE

Balikpapan

Bandjermasin

Tanjungkarang-Telukbetung

-1

1833

1 October 2009 1:52:47 UTC

Ban g ka

Palembang

5°

0°

6

Palembang

2007

Bor ne o

0°

Samarinda

Palangkaraya

Bengkulu

Southern Sumatra

2007

Sip u ra

Sumatra

0

5°

ra

AUSTRALIA PLATE

1995

LA

IA

I N D O N E S I A

Jambi

1

at

Sib er u t

Y

A SI

A

YS

Pontianak

Padang

I N D O N E S I A

Jambi

A

Pontianak

m

Padang

S I N G A P ONote: R EUnlike the sequences shown, the M7.6 earthquake

Su

2007 2007

A

M

of 30 September 2009 is not likely an interplate thrust event.

Pekanbaru

2006

SI

Nia s

Singapore

LA

45 km (30 miles) WNW of Padang, Sumatra, Indonesia 220 km (135 miles) SW of Pekanbaru, Sumatra, Indonesia 475 km (295 miles) SSW of KUALA LUMPUR, Malaysia

A Johor Baharu

SINGAPORE

Pekanbaru 0°

0.788° S., 99.961° E. Depth 80 km Mw = 7.6 (USGS)

M

Singapore

5°

30 September 2009 10:16:09 UTC

SI

2005

1797

Kuantan New Port

Y

Seremban

2005

0°

Kuala Lumpur

2008

Sim eu lu e

45 mm/yr

LA

2004

2002

A

Medan

Y

M

1990

Kuala Lumpur Seremban

1991

BRUNEI

Southern Sumatra

Kuantan New Port

A

Kuala Terengganu Ipoh

2004

Medan

5°

L

Pinang

BRUNEI

A

5°

Sumatra Fault

Kuala Terengganu

M

Banda Aceh

115°

Ipoh

SUNDA PLATE

Kota Baharu

110°

Kota Baharu

-6

105°

P

Nico b a r I s. (I n d ia)

Pal aw a n

100°

105°

Neg ro s

A R LA O W U A G N H

95°

100°

0

BURMA Western Indonesia Earthquakes, 1988 - June 2009 PLATE

95°

-4

Phnom Penh

Map prepared by U.S. Geological Survey National Earthquake Information Center April 2008, edited 30 September 2009 Map not approved for release by Director USGS original URL http://earthquake.usgs.gov/research/hazmaps/products_data/

40

Da Lat

0

And a ma n I s. (I n d ia)

Nha Trang

30

CAMBODIA

2002, 2008

SINGAPORE 2005

0°

0°

INDONESIA Sumat ra

1797

2007 5°

1833

Greater

5°

Jakarta

2000

Bandung

Java

INDIAN OCEAN

10°

95°

0

Scale 1:10,000,000 250

10°

100°

500 Kilometers

105°