I Felt by very few people; barely noticeable. II Felt by a few people, especially on upper floors. III Noticeable indoors, especially on upper floors, but may not be recognized as an earthquake. IV ...

The Japan Meteorological Agency has a unique seismic scale called ... Zero intensity is detected by seismometers but not perceptible to people. The Great East Japan Earthquake on March 11, 2011 ...