Japan's biggest recorded earthquake appears to have moved the island by about 2.4 metres, according to the US Geological Survey. That's a reasonable number. Eight feet, that's certainly going to be in the ballpark," said USGS seismologist Paul Earle.
Friday's 9.0 magnitude quake unleashed a terrifying tsunami that engulfed towns and cities on Japan's northeastern coast, destroying everything in its path in what Prime Minister Naoto Kan said was an "unprecedented national disaster".
The quake and its tectonic shift resulted from "thrust faulting" along the boundary of the Pacific and North America plates, News.com.au quoted the USGS, as saying.
"With an earthquake this large, you can get these huge ground shifts. On the actual fault you can get 20 metres of relative movement, on the two sides of the fault," Earle said.
He said similar movements would have been seen for Chile and Indonesia.
In December 2004, a 9.1 magnitude quake off Sumatra caused a tsunami that killed an estimated 228,000 people. An 8.8 quake off the coast of Chile in February 2010 killed more than 500.