Ring of Fire subduction of the Pacific Plate and the Philippine Sea Plate. As many as 1,500 earthquakes are recorded yearly, and magnitudes of 4 to 6 are not uncommon. Minor tremors occur almost daily in one part of the country or another, causing some slight shaking of buildings. Major earthquakes occur infrequently; the most famous in the 20th century were: the Great Kantō earthquake of 1923, in which 130,000 people died; and the Great Hanshin earthquake of 17 January 1995, in which 6,434 people died. On March 11, 2011 a magnitude 9.0 earthquake hit Japan, the country's biggest ever and the fifth
2011 Tōhoku earthquake and tsunami intensities were smaller than the actual ones in some places, especially in Kanto, Koshinetsu, and Northern Tōhoku regions where the populace warning did not trigger. According to the JMA , reasons for the underestimation include a saturated magnitude scale when using maximum amplitude as input, failure to fully take into account the area of the hypocenter, and the initial amplitude of the earthquake being less than that which would be predicted by an empirical relationship. There were also cases where large differences between estimated intensities by the Earthquake Early Warning system and the actual intensities occurred in the aftershocks and