sign in sign up
<<
Home , 1907 Sumatra earthquake, Greater Sunda Islands, Siberut, Simeulue, Sunda Trench

U.S. DEPARTMENT OF THE INTERIOR SUMMARY MAP XXX U.S. GEOLOGICAL SURVEY Prepared in cooperation with the Global Seismographic M7.4 , Earthquake of 20 February 2008 Network

Tectonic Setting Epicentral 80° 90° 100° 110° 90° 92° 94° 96° 98° 100° 102° 20° 20° Phatthalung L A O S EXPLANATION Trang Mag ≥ 7.0 1934 Nicobar Is. Songkhla 0 - 69 km (India) Simeulue, Indonesia INDIA PLATE Pattani 70 - 299 1955 20 FebruSaraytu 2n008 8:08:32 UTC T H A I L A N D Yala 300 - 600 Kangar Narathiwat 2.778° N., 95.978° E. P h i l i p p i n e V I E T N A M Depth 35 km F a u l t Rupture Zones Alor Setar Kota Baharu B A Y O F C A M B O D I A Mw = 7.4 (USGS) 6° 6° B E N G A L 1941 Year of Earthquake 1983 An earthquake occurred 310 km (195 miles) SSE A N D A M A N 2005 Banda S E A Gulf of , , Indonesia, 310 km (195 10° of 10° 1936 miles) WSW Poifn aMngedan, Sumatra, Indonesia, 335 km Thailand S O U T H 2004 BURMA 1881 (210 miles) WNW of Sibolga, Sumatra, Indonesia, C H I N A N PLATE A 1545 (960 miles) NW of , . Earth- S E A W H 1941 A G S R I L A N K A L U 2004 A O 1917 quakes of this type sometimes cause ; P R T 1881 however, the USGS has no information than an actual has been genIpeorhated. 1861 1935

B R U N E I M 1833 A Kuala Lipis 2004 L 1916 A Y S u m a t r a F a u l t 2008 S 4° 4° 2004 I A Plate Boundaries I S 2005 A Y A L 1936 M a l a y s i a A M i d - I n d i a n 1969 M Medan 1907 S I N G A P O R E 1976 B a s i n Transform 1861 S 1935 u 1938 0° m 0° a Kuala Lumpur 2005 tr Divergent EPICENTRAL a I N D O N E S I A Shah Alam REGION 1943 Seremban 1928 1833 2007 Convergent 2007 Greater 2000 Volcanoes Simeulue Melaka 1914 2007 J A V A S E A 1907 1969

Lesser Sunda Islands 2° 2°

I n

AUSTRALIA PLATE v

e

e Java s g

t

d i 55 2006

g i 1943 a mm/yr R

t

1994 10° o S 10° t U r N EXPLANATION D A 1977 ( s J AV R A ) T R E N C H S u m a t r a a i d 1971

E Pekanbaru g Main Shock M7.4

e I N D I A N

y

t 1984

e Aftershocks Pini 80° 90° 100° 110° 1946

n O C E A N RELATIVE PLATE MOTIONS i Ear0t°hquake Magnitude 0° N SCALE 1936 1:20,000,000 1935 Kilometers 4.00 - 5.99 The broad red vector represents the motion of 0 200 400 800 1,200 1,600 1998 Tanahbala S the Plate relative to the Sunda Plate u 6.00 - 6.99 m in the region. The motion of the Australia a t Plate is generally 50 - 60 mm/yr north and 7.00 - 7.99 Padang1943 ra slightly eastward with respect to the Sunda 1939 Plate. 8.001 9-9 98.99 1943

9.00 - 9.99 Seismic Hazard Siberut 1909 2° 2° 80° 90° 100° 110° Earthquake Depth Vishakhapatnam Vientiane Vinh 0 - 69 Sipora Hyderabad Pegu Udon Thani 90° 92° 94° 96° 98° 100° 102° BasseinRangoon Phitsanulok 70 - 299 Scale at the Equator 1:4,392,300 Slip (mm) Moulmein Khon Kaen Hue Nakhon Sawan Savannakhet Da Nang 300 - 700 Mercator Projection Ubon Ratchathani 0.00 - 10.00 Finite Model Nakhon Ratchasima Quang Ngai Kilometers 0 100 200 400 10.01 - 20.00 Tavoy Bangkok Play Cu for M7.4 Earthquake Madras Siemreab Qui Nhon Bangalore Samut SakhonBatdambang 20.01 - 30.00 Buon Me Thuot Nha Trang Pondicherry Port Blair Phnom Penh 30.01 - 40.00 Bien Hoa Ho Chi Minh City 40.01 - 50.00 My Tho Phan Thiet Cochin Rach Gia Can Tho 10° 10° Madurai Bac Lieu TECTONIC SUMMARY 50.01 - 60.00 Trivandrum Nakhon Si Thammarat 60.01 - 70.00 The magnitude 7.4 Simeulue, Indonesia earthquake of February 20, Significant Mag >= 7.5 Colombo Songkhla 2008 occurred as the result of thrust faulting on the boundary between 70.01 - 80.00 Yala Kota Baharu Year Mon Day Time Lat Long Dep Mag Galle Alor Setar the Australia and Sunda plates. At the location of this earthquake, the Banda Aceh 1907 01 04 0519 2.000 94.500 50 7.5 80.01 - 90.00 Pinang Kuala Terengganu Australia plate moves north-northeast with respect to the Sunda plate at Ipoh Bandar Seri Begawan 1935 12 28 0235 -0.345 98.147 35 7.8 a velocity of about 55 mm/year. The direction of relative plate motion is 90.01 - 100.00 Medan 1943 06 09 0306 -1.000 101.000 50 7.5 Kuala Lumpur oblique to the orientation of the plate boundary offshore of the west 1969 11 21 0205 1.973 94.574 11 7.6 100.01 - 110.00 Seremban - 2004 12 26 0058 3.295 95.982 30 9.0 17 Melaka coast of Sumatra. The component of plate-motion perpendicular to the 0 Johor Baharu Singapore Kuching boundary is accommodated by thrust faulting on the offshore plate- 2004 12 26 0421 6.910 92.958 39 7.5 2005 03 28 1609 2.085 97.108 30 8.6 Pekanbaru boundary, with the Australia plate subducting beneath the Sunda plate. FINITE FAULT MODEL Pontianak 0° 0° Much of the component of plate motion parallel to the plate boundary is Balikpapan accommodated by strike-skip faulting on the Sumatra fault, which is Distribution of the amplitude Jambi EPICENTRAL REGION Palangkaraya inland on Sumatra proper. and direction of slip for Palembang subfault elements (small Bandjermasin Bengkulu This earthquake occurred at the south end of the rupture zone of the rectangles) of the fault rupture great magnitude 9.1 earthquake of December 26, 2004 and at the north model are determined from the Tanjungkarang-Telukbetung inversion of teleseismic body ) end of the rupture zone of the magnitude 8.6 Nias Island earthquake of m Jakarta waveforms. Arrows indicate k March 28, 2005, where the 2004 and 2005 rupture zones nearly abut. DATA SOURCES ( Bandung the amplitude and direction of ip Surabaya The earthquake of December 26, 2004, produced the devastating Indian d t slip (of the hanging wall with n s Yogyakarta EARTHQUAKES AND SEISMIC HAZARD 12 w a Semarang Ocean tsunami of that date. Since 2000, much of the 0 o e Mataram USGS, National Earthquake Information Center REFERENCES respect to the foot wall); the d th D e r Seismic hazard is expressed as peak between the northern to Eggano Island, a distance of NOAA, National Geophysical Data Center is c o slip amount is also color-coded ta n n N ground acceleration (PGA) on firm more than 2,000 km, has ruptured in a series of large subduction zone IASPEI, Centennial Catalog (1900 - 1999) and Bird, P., 2003, An updated digital model of plate boundaries: as shown. The view of the ce ta ° 10° rock, in meters/sec², expected to be 10° extensions (Engdahl and Villaseñor, 2002) Geochem. Geophys. Geosyst., v. 4, no. 3, pp. 1027- 80. a is 3 earthquakes. rupture plane is from above. lo D ip ng exceeded in a 50-yr period with a HDF (unpublished earthquake catalog) (Engdahl, 2003) s D tri probability of 10 percent. Global Seismic Hazard Assessment Program Engdahl, E.R. and Villaseñor, A., 2002, Global Seismicity: ke The strike of the fault rupture 2 1900 - 1999, chap. 41 of Lee, W.H.K., and others,eds., 95 AND FAULT MODEL International Earthquake and Engineering Seismology, plane is N65W and the dip is 3 ° ( N 80° 90° 100° 110° NE. The dimensions of the 65 PB2002 (Bird, 2003) Part A: New York, N.Y., Elsevier Academeic Press, 932 p. W SCALE 1:20,000,000 Finite Fault Model, Chen Ji, UC Santa Barbara (2007) subfault elements are 10 km in ) ( DISCLAIMER km Kilometers Engdahl, E.R., Van der Hilst, R.D., and Buland, R.P., 1998, the strike direction and 5 km in ) 0 200 400 800 1,200 1,600 BASE MAP Global teleseismic earthquake relocation with improved trav- the dip direction. The total 0 Base map data, such as place names and political NIMA and ESRI, Digital Chart of the World el times and procedures for depth determination: Bull. Seism. fault plane dimensions are 120 0 Peak Ground Acceleration in m/sec**2 boundaries, are the best available but may not be USGS, EROS Data Center Soc. Amer., v. 88, p. 722-743. km along strike and 170 km current or may contain inaccuracies and therefore NOAA GEBCO and GLOBE Elevation Models down dip. should not be regarded as having official significance. Map prepared by U.S. Geological Survey National Earthquake Information Center .2 .4 .8 1.6 2.4 3.2 4.0 4.8 13 September 2007 Map not approved for release by Director USGS