Tokyo sees high quake probability, scientists warn

Gibson said that while the area is a very active one seismically, building standards are high, therefore reducing the damage caused by earthquakes. Buildings in Tokyo held up well in the face of the "Tohoku" quake. Reinforced concrete and anti-seismic systems in buildings are among features that have helped absorb shocks when earthquakes occur.

"A magnitude 7.0 earthquake is very much smaller than the magnitude 9.0 Tohoku earthquake," he wrote. "It would need 1,000 magnitude-7.0 earthquakes to release as much strain energy as the magnitude 9.0. The fault rupture size is tens of kilometers, rather than hundreds of kilometers, and the fault displacement two to three meters rather than 20 to 30 meters."

Serious damage could be limited, if it occurs offshore, he added. And the shallower the quake, such as within 10 kilometers of the surface, the more localized the damage.