“If there is drastic plate movement, there is no guarantee that the scale of the quake will be in line with the government’s prediction of up to magnitude 7.3.”-Hirata Naoshi, Earthquake Research Committee
The University of Tokyo’s Earthquake Research Institute believes that major earthquakes are in the near future for Tokyo city, and Ibaraki Prefecture, no thanks to the 11 March 2011 9.0 quake.
Even though the 11 March earthquake was at least a hundred miles north of Tokyo, it was so powerful that the tectonic plate under Tokyo has changed so dramatically, that scientists think a massive quake caused by action on two or more areas of the plate is highly likely. Since 11 March, the number of Tokyo quakes of magnitude 3 or greater has increased by fourfold.
Tokyo is subject to earthquakes that are located along plate boundaries, as well as quakes that happen along fault lines within a single plate.
Ibaraki Prefecture, just south of Fukushima Prefecture, is even worse off. Since 11 March, quakes of magnitude 3 or greater have increased by 20 times!
The high tectonic activity is on the coastline, inland quake activity has not increased, but it has changed.
Japanese scientists say that recent inland quakes are much more shallower that past earthquakes.