The earthquake that generated the great Indian Ocean tsunami of 2004 is estimated to have released the energy of 23,000 Hiroshima-type atomic bombs, according to the U.S. Geological Survey (USGS).

Giant forces that had been building up deep in the Earth for hundreds of years were released suddenly on December 26, shaking the ground violently and unleashing a series of killer waves that sped across the Indian Ocean at the speed of a jet airliner.

By the end of the day more than 150,000 people were dead or missing and millions more were homeless in 11 countries, making it perhaps the most destructive tsunami in history.

The epicenter of the 9.0 magnitude quake was under the Indian Ocean near the west coast of