Tsunami quake wobbled Earth's axis
http://theage.com.au/news/World/Tsun...996533891.html
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Tsunami quake wobbled Earth's axis
An earthquake that unleashed deadly tidal waves on Asia was so powerful it made the Earth wobble on its axis and permanently altered the regional map, US geophysicists said today.
The 9.0-magnitude temblor that struck 250 km south-east of Sumatra island on 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 modelling, some of the smaller islands off the south-west coast of Sumatra may have moved to the south-west by about 20 metres. That is a lot of slip."
The north-western tip of the Indonesian island of Sumatra may also have shifted to the south-west by around 36 metres, 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 to the massive amount of energy exerted and the sudden shift in mass," Hudnut said.
