Earthquake Details

Magnitude: 7.7

Date-Time: Tuesday, April 06, 2010 at 22:15:02 UTC
Wednesday, April 07, 2010 at 05:15:02 AM at epicenter
Time of Earthquake in other Time Zones

Location: 2.360°N, 97.132°E

Depth: 31 km (19.3 miles) set by location program

Region: NORTHERN SUMATRA, INDONESIA

Distances: 200 km (125 miles) WNW of Sibolga, Sumatra, Indonesia
215 km (135 miles) SW of Medan, Sumatra, Indonesia
515 km (320 miles) W of KUALA LUMPUR, Malaysia
1425 km (880 miles) NW of JAKARTA, Java, Indonesia

Location Uncertainty: horizontal +/- 4.8 km (3.0 miles); depth fixed by location program

Parameters: NST=240, Nph=240, Dmin=317.9 km, Rmss=1.08 sec, Gp= 29°, M-type=teleseismic moment magnitude (Mw), Version=7

Source: USGS NEIC (WDCS-D)

Event ID: us2010utc5

Earthquake Summary

Tectonic Summary

The Banyak Islands, Sumatra earthquake of April 6, 2010 occurred as a result of thrust faulting on or near the subduction interface plate boundary between the Australia-India and Sunda plates. At the location of this earthquake, the Australia and India Plates move north-northeast with respect to the Sunda plate at a velocity of approximately 60-65 mm/yr. On the basis of the currently available fault mechanism information and earthquake depth, it is likely that this earthquake occurred along the plate interface.

The subduction zone surrounding the immediate region of this event last slipped during the Mw 8.6 earthquake of March 2005, and today's event appears to have occurred within the rupture zone of that earthquake. Today's earthquake is the latest in a sequence of large ruptures along the Sunda megathrust, including two M 7.3 earthquakes beneath Simeulue 125 km to the north in 2002 and 2008; a M 9.1 earthquake that ruptured to within 125 km north of this earthquake in 2004; a M 7.9 250 km to the south in 2007; a M 8.4 375 km to the south in 2007; and a M 7.5 260 km to the south near Padang in 2009.