Magnitude 7.5 - SOUTHERN SUMATRA, INDONESIA

2009 September 30 10:16:09 UTC

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Earthquake Details

Magnitude7.5
Date-Time
Location 0.725°S, 99.856°E
Depth81 km (50.3 miles) set by location program
RegionSOUTHERN SUMATRA, INDONESIA
Distances60 km (35 miles) WNW of Padang, Sumatra, Indonesia
225 km (140 miles) SW of Pekanbaru, Sumatra, Indonesia
470 km (295 miles) SSW of KUALA LUMPUR, Malaysia
975 km (600 miles) NW of JAKARTA, Java, Indonesia
Location Uncertaintyhorizontal +/- 4.2 km (2.6 miles); depth fixed by location program
ParametersNST=405, Nph=405, Dmin=534.3 km, Rmss=0.92 sec, Gp= 18°,
M-type=teleseismic moment magnitude (Mw), Version=A
Source
  • USGS NEIC (WDCS-D)
Event IDus2009mebz
  • This event has been reviewed by a seismologist.
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Earthquake Summary

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Earthquake Summary Poster

Felt Reports

At least 1100 people were killed, 2181 were injured and thousands are still unaccounted for in the Padang area. More than 2650 buildings have been damaged in the area and landslides have disrupted power and communications. Felt (VII) at Padang. Widely felt throughout Sumatra and Java, Indonesia, Malaysia, Singapore and Thailand. A small local tsunami with wave heights of 27 centimeters (amplitude measured relative to normal sea level) was generated.

Tectonic Summary

The southern Sumatra earthquake of September 30, 2009 occurred as a result of oblique-thrust faulting near the subduction interface plate boundary between the Australian and Sunda plates. At the location of this earthquake, the Australian Plate moves north-northeast with respect to the Sunda plate at a velocity of approximately 60 mm/yr. On the basis of the currently available fault mechanism information and earthquake depth of 80 km, it is likely that this earthquake occurred within the subducting Australian Plate rather than on the plate interface itself. The recent earthquake was deeper than typical subduction thrust earthquakes that generally occur at depths less than 50 km. The subduction zone surrounding the immediate region of this event has not witnessed a megathrust earthquake in the recent past, rupturing last in an earthquake of M 8.5 or larger in 1797. Approximately 350 km to the south, a 250 km section of the plate boundary slipped during an Mw 8.4 earthquake in September 2007, while approximately 300 km to the north, a 350 km section slipped during the Mw 8.7 earthquake of March 2005. In early 2008, the plate boundary updip of today’s earthquake was active in a sequence of Mw 5-6 earthquakes. It is not clear how today’s earthquake is related to the sequence of megathrust subduction zone events on the shallower section of the plate boundary.

Earthquake Information for Asia

Earthquake Information for Indonesia

Seismic Hazard of Western Indonesia Poster

Tsunami Information

The earthquake locations and magnitudes cited in NOAA tsunami bulletins are very preliminary and may be superseded by USGS locations and magnitudes computed using more extensive data sets.

Tsunami Bulletins for this Earthquake

No Bulletins have been issued at this time.

General Tsunami Information