UK Daily Mail 
March 21, 2011
Geologists have warned that another powerful earthquake could hit Tokyo because the one that struck on March 11, which was of a size 9 magnitude, has altered the earth’s surface.
The monster quake has put pressure on the fault lines near the Japanese capital and experts have suggested that a size 7.5 magnitude earthquake could hit.
The structure of the tectonic plates and fault lines around the city makes it unlikely that Tokyo, home to 13million people, would be hit by a quake anywhere near the intensity of the one 10 days ago, said Roger Musson of the British Geological Survey.
But given the vast population – the capital and its surroundings are home to 39million people (including in the suburbs) – any strong tremor could be devastating.
‘Even if you’ve got, let’s say, a 7.5, that would be serious,’ the seismologist said.
Japan is located on the Ring of Fire, an arc of volcanoes and fault lines spanning the Pacific Basin, and is regularly hit by earthquakes.