LOS ANGELES :

An earthquake that unleashed deadly tsunami waves on Asia was so powerful it made the Earth wobble on its axis and permanently altered the regional map, US geophysicists said Monday.

The 9.0-magnitude temblor that struck 250 kilometers (155 miles) southeast of Sumatra island Sunday may have moved small islands as much as 20 metres, according to one expert.

"That earthquake has changed the map," US Geological Survey expert Ken Hudnut told AFP.

"Based on seismic modeling, some of the smaller islands off the southwest coast of Sumatra may have moved to the southwest by about 20 metres. That is a lot of slip."

The northwestern tip of the Indonesian territory of Sumatra may also have shifted to the southwest by around 36 meters (120 feet), Hudnut said.

In addition, the energy released as the two sides of the undersea fault slipped against each other made the Earth wobble on its axis, Hudnut said.

"We can detect very slight motions of the Earth and I would expect that the Earth wobbled in its orbit when the earthquake occurred due the massive amount of energy exerted and the sudden shift in mass," Hudnut said.