The 9.3 magnitude Indian Ocean earthquake occurred December 26, 2004.  The epicenter was off the west coast of Sumatra, Indonesia, and the earthquake triggered a series of deadly tsunamis along all the landmasses surrounding the Indian Ocean.  Some of the waves making land fall were a hundred feet high. 

Victims numbered nearly a quarter of a million people in eleven countries.  This earthquake had a long duration of nearly 10 minutes,  it caused the entire planet to vibrate, and it triggered earthquakes in distant localities.  The energy released has been estimated at about 26.3 megatons of TNT.

The earthquake was caused by a double slippage along the fault line between the India Tectonic Plate and the Burma Plate.  The slip began off the coast of Aceh and proceeded northwest.  At one point it stopped for a couple of minutes, but then it continued slipping again in the northwest direction.

This earthquake came just three days after a magnitude 8.1 earthquake west of New Zealand.  It is unusual for two violent quakes to happen so close in time and distance. 

Just 44.6 hours after the Indian Ocean quake, Earth experienced the brightest gamma ray burst (GBR) ever recorded by 100 times.  Its brightness rivaled the brightness of the full Moon, but its wavelengths were in the gamma ray range, and during a flicker of time it outshone the full Moon by a factor of two.  It has been estimated that the source of the GBR was about 20,000 light years away.  Evidently a shock wave from the source is emitted prior to the gamma ray burst, and that shock wave was responsible for the earthquake. 

On December 27, 2004, more that a dozen spacecraft recorded this gamma ray burst.  The super flare irradiated Earth with more total energy than any solar flair.

The expanding fireball outburst  of the December 27, 2004 GRB

GRBCREDIT: G.B. Taylor, NRAO/AUI/NSF