Hi Juliet. The most logical reason there wasn’t any quake in the Tokyo area was that there wasn’t one going to occur in the first place. The area surrounding Tokyo, Yokohama and most of the Kanto Plains area is very heavy monitored by dilational strain meters, tensor strain meter, tilt meter, water level in wells, magnetometers and Radon 222 emissions and in some areas the VAN method that has been said to have worked in Greece. There wasn’t any change in the any of the data for the area. To put it another way the people who saw what they believed to be a major quake about to occur it the Tokyo area were wrong. If there data showed something for the Japan area then they need to improve upon interpreting what they see in regards to a more precise location.

About two months prior to the Hokkaido quake the Japanese authorities did identified the area of the M>8.3 quake as the most likely location for a major quake in the next 30 years. That 30 year time period occurred a lot sooner then they expected. Take Care…Don in creepy town