Map prepared by U.S. Geological SurveyNational Earthquake Information Center20 November 2008Map not approved for release by Director USGS

EARTHQUAKE SUMMARY MAP XXXU.S. DEPARTMENT OF THE INTERIORU.S. GEOLOGICAL SURVEY

DISCLAIMERBase map data, such as place names and politicalboundaries, are the best available but may not be current or may contain inaccuracies and thereforeshould not be regarded as having official significance.

B

B'

1997

C e l e b e s S e a

Mo l uc c

a S e a

B a n d a S e a

B O R N E OS U L A W E S I

M O L U C C A S

A'

A

2007

WesternMindanao

Sabah

Kalimantan Timur

Sulawesi Utara Maluku

Sulawesi Tengah

Sulawesi Tenggara

Sulawesi Selatan

SouthernMindanao

Palu

Manado

Samarinda

Balikpapan

1918

1932

1905

1913

1907

1910

1936

19381939

1957

1968

1972

1984

1986

1990

1991

1996

1998

2000

1965

128°

128°

126°

126°

124°

124°

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122°

120°

120°

118°

118°

6° 6°

4° 4°

2° 2°

0° 0°

2° 2°

P HI L I P P I N E T R

E NC

HPALAWAN

TROUGH

SU N DA ( J AVA ) TR E N C H

SUNDA PLATE

MOLUCCASEA

PLATE

BANDA SEAPLATE

TIMORPLATE

PHILIPPINE SEA PLATE

CAROLINEPLATE

BIRD'S HEADPLATE

MAOKEPLATE

AUSTRALIA PLATE

P H I L I P P I N E S E A

S O U T HC H I N A

S E A

A R A F U R A S E A

B A N D A S E AJ A VA S E A New Gu inea

BorneoSumatra

Java Lesser Sunda IslandsGreater Sunda Is lands

S u m a t r a F a u l t

P h i l i p p i n eF a u l t

I N D O N E S I A

T H A I L A N D

S I N G A P O R E

MA L A Y S I A

T I M O R - L E S T E

C A M B O D I AV I E T N A M

L A O S

P H I L I P P I N E S

B R U N E I

M A L A Y S I A

P A P U AN E W G U I N E A

Gulfof

Thailand

W e s tM a r i a n a

B a s i n

Kyus

hu -

Pa l

a u R

i dg e

N o r t hA u s t r a l i a n

B a s i n

C e l e b e sB a s i n

P h i l i p p i n eB a s i n

W e s t C a r o l i n eB a s i n

1941

AUSTRALIA PLATE

CAROLINEPLATE

PHILIPPINE SEAPLATE

EURASIA PLATE

20051861

2004

1833

1881

140°

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130°

130°

120°

120°

110°

110°

10° 10°

0° 0°

10° 10°

M7.4 Sulawesi, Indonesia, Earthquake of 16 November 2008

0 250 500125Kilometers

PAPUA NEW GUINEA

IN DO N ES IA

PHI L I P P I NE S

VIETNAMCAMBODIA

LAOSTHAILAND

MALAYSIA

KhonKaen

BalikpapanJambiPalangkaraya

BandjermasinBengkulu KendariTanjungkarang-

Telukbetung

YogyakartaDiliMataram

Kupang

Darwin

KuantanNew Port

Phitsanulok Savannakhet Hue

Pinang

Da NangQuangNgai

NakhonRatchasima

Play CuQui NhonSamut Prakan

SamutSakhon

SiemreabBatdambang Buon MeThuot Nha TrangDa Lat

BienHoa Phan

ThietTan An

Ambon

VinhLongCan ThoRach Gia

SocTrang

Bac LieuNakhon SiThammarat

SongkhlaYala

KotaBaharu

AlorSetar

KotaKinabaluKuala

TerengganuBandar

SeriBegawanIpoh

SerembanMelakaKuching

JohorBaharu

ManadoPekanbaru

Pontianak SamarindaPadang

Jakarta

QuezonCityManila

PhnomPenh

Ho Chi Minh City

Davao

KualaLumpur

Palembang

Bandung SemarangSurabaya

Singapore

Makassar

140°

140°

130°

130°

120°

120°

110°

110°

100°

100°

10° 10°

0° 0°

10° 10° DATA SOURCESEARTHQUAKES AND SEISMIC HAZARD USGS, National Earthquake Information Center NOAA, National Geophysical Data Center IASPEI, Centennial Catalog (1900 - 1999) and extensions (Engdahl and Villaseñor, 2002) HDF (unpublished earthquake catalog) (Engdahl, 2003) Global Seismic Hazard Assessment ProgramPLATE TECTONICS AND FAULT MODEL PB2002 (Bird, 2003) Finite Fault Model, Chen Ji, UC Santa Barbara (2007)BASE MAP NIMA and ESRI, Digital Chart of the World USGS, EROS Data Center NOAA GEBCO and GLOBE Elevation Models

0 500 1,000 1,500250Kilometers

Scale

Prepared in cooperation

with the Global Seismographic

Network

Tectonic Setting

Seismic Hazard

Epicentral Region

Minahasa, Sulawesi 16 November 2008 17:02:32 UTC 1.289° N., 122.102° E.Depth 26.1 kmMw = 7.4 (USGS)At least three people killed, 20 injured, 700 houses collapsed and communications disrupted in the Buol area. One person killed, 23 injured and many buildings damaged in Gorontalo.

TECTONIC SUMMARYThe magnitude 7.4 Sulawesi, Indonesia earthquake of November 16,2008 occurred as a result of thrust faulting on a plate-boundary that ismarked by the North Sulawesi trench, separating the Celebes Sea basinand the Minahassa peninsula. Eastern Indonesia is characterized bycomplex tectonics in which motions of numerous small plates areaccommodating large-scale convergence between the Australia, Pacific,and Eurasia plates. At the location of today’s earthquake, the CelebesSea basin (commonly considered part of the Sunda plate) moves southwith respect to the Minahassa peninsula (part of the Molucca Sea plate)at a velocity of about 30 mm/year. The lithosphere of the Celebes Seabasin is thrust beneath that of the Minahassa peninsula and is seismicallyactive to a depth of about 250 km. Earthquakes in the epicentral regionhaving depths greater than 300 km (sections A -- A' and B -- B') areoccurring in lithosphere that has been subducted from the east ratherthan in the southward subducting lishosphere of the Celebes Sea basin.The earthquake occurred approximately 25 km off the northern coast ofthe Minahassa peninsula of the Island of Sulawesi in an area that hasseen large earthquakes in the past. For example, a damaging magnitude7.6 earthquake occurred on April 18, 1990 approximately 85 km east oftoday’s earthquake. The magnitude 7.6 earthquake in 1990 was followeda year later by a magnitude 7.5 earthquake in approximately the sameplace. More recently a magnitude 7.0 occurred within 45 km of today’searthquake on November 25, 1997. The 1997 earthquake caused damageto at least 90 building in the Gorontalo area of northern Sulawesi.

Seismic hazard is expressed as peakground acceleration (PGA) on firmrock, in meters/sec², expected to beexceeded in a 50-yr period with aprobability of 10 percent.

EXPLANATIONMag ≥ 7.0

0 - 69 km70 - 299300 - 600

Plate BoundariesSubductionTransformDivergent

ConvergentVolcanoes

RELATIVE PLATE MOTIONSEastern Indonesia is a region of complex plateinteractions. From a global perspective, easternIndonesia consists of microplates whose relativemotions absorb the convergence of the Pacific,Australia, and Eurasia plates.( Pacific Plateboundary is east of this map).

0 500 1,000 1,500250Kilometers

Scale

REFERENCESBird, P., 2003, An updated digital model of plate boundaries: Geochem. Geophys. Geosyst., v. 4, no. 3, pp. 1027- 80.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.Engdahl, E.R., Van der Hilst, R.D., and Buland, R.P., 1998, Global teleseismic earthquake relocation with improved trav- el times and procedures for depth determination: Bull. Seism. Soc. Amer., v. 88, p. 722-743.

1:4,000,000Scale

Significant Earthquakes Mag >= 7.5

Year Mon Day Time Lat Long Dep Mag1905 01 22 0243 1.000 123.000 90 7.81907 06 25 1754 1.000 127.000 200 7.51910 12 16 1445 4.500 126.500 0 7.61913 03 14 0845 4.500 126.500 0 7.91918 08 15 1218 5.653 123.563 35 8.21932 05 14 1311 0.258 126.169 35 8.11936 04 01 0209 4.165 126.521 35 7.71938 05 19 1708 -0.366 119.525 49.4 7.51939 12 21 2100 -0.208 122.565 35 7.81957 09 24 0821 5.230 127.117 35 7.71965 01 24 0011 -2.455 125.965 28.4 8.21968 08 10 0207 1.422 126.260 19.6 7.61972 06 11 1641 3.866 124.236 330 7.81984 11 20 0815 5.129 125.114 167 7.51986 08 14 1939 1.805 126.485 30.9 7.51990 04 18 1339 1.186 122.799 26 7.61991 06 20 0518 1.226 122.789 32.5 7.51996 01 01 0805 0.725 119.932 24 7.91998 11 29 1410 -1.916 124.823 16 7.72000 05 04 0421 -1.153 123.478 26 7.62007 01 21 1127 1.065 126.282 22 7.5

Peak Ground Acceleration in m/sec**2

.2 .4 .8 1.6 2.4 3.2 4.0 4.8

EPICENTRAL REGION

EXPLANATIONMain Shock

Earthquake Magnitude5.50 - 5.996.00 - 6.997.00 - 7.998.00 - 8.99

9.00 - 9.99

Earthquake Depth0 - 6970 - 299300 - 700

1:20,000,000

1:20,000,000

EPICENTRAL REGION

Depth ProfilesA A'

B B'Distance (km)

Depth

(km)

Distance (km) -100

-100

0

0

100

100

200

200

300

300

-600 -600

-500 -500

-400 -400

-300 -300

-200 -200

-100 -100

0 0 -100

-100

0

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800 -700 -700

-600 -600

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-300 -300

-200 -200

-100 -100

0 0

Note on earthquakes: From 1900 - 1963, earthquakes shown are fromCentennial Catalog, magnitudes greater than 5.5. From 1964 - 2002,earthquakes are from HDF catalog, magnitudes greater than 4.5. From2003 to present, earthquakes are from NEIC, magnitudes greater than 4.5.