As per US Geological Survey:

Earthquake Details

This event has been reviewed by a seismologist.

Magnitude 8.7
Date-Time

Wednesday, April 11, 2012 at 08:38:38 UTC
Wednesday, April 11, 2012 at 02:38:38 PM at epicenter
Time of Earthquake in other Time Zones

Location: 2.348°N, 93.073°E
Depth 33 km (20.5 miles)
Region OFF THE WEST COAST OF NORTHERN SUMATRA
Distances 434 km (269 miles) SW of Banda Aceh, Sumatra, Indonesia
550 km (341 miles) SW of Lhokseumawe, Sumatra, Indonesia
963 km (598 miles) W of KUALA LUMPUR, Malaysia
1797 km (1116 miles) WNW of JAKARTA, Java, Indonesia
Location Uncertainty horizontal +/- 14 km (8.7 miles); depth +/- 2.8 km (1.7 miles)
Parameters NST=243, Nph=243, Dmin=514.3 km, Rmss=1.67 sec, Gp= 36°,
M-type=regional moment magnitude (Mw), Version=8
Source

Magnitude: USGS NEIC (WDCS-D)
Location: USGS NEIC (WDCS-D)

Event ID usc000905e

As per IMD:

PRELIMINARY EARTHQUAKE REPORT

Date of Occurrence:11/04/2012

Time:14:08:35.0 HRS(IST)

Intensity:GREAT

Magnitude:8.5

Epicentre:Lat. 2.3°N Long. 93.0°E

Region:OFF WEST COAST OF NORTHERN SUMATRA