Why Japan Experiences Frequent Earthquakes
Japan sits at the intersection of four tectonic plates—Pacific, North American, Eurasian, and Philippine Sea plates. This unique geographical position results in approximately 20% of the world's earthquakes occurring in Japan, making it one of the most seismically active nations.
Types of Japanese Earthquakes
Japanese earthquakes fall into two main categories: subduction zone earthquakes (mega-thrust earthquakes at plate boundaries) and inland crustal earthquakes. Subduction zone earthquakes, such as the 2011 Great East Japan Earthquake (magnitude 9.0), can be extremely powerful. Inland earthquakes, like the 1995 Kobe earthquake (magnitude 7.3), occur more frequently and can cause significant urban damage.
Risk Assessment Across Japan
Nearly 99% of Japanese municipalities face some level of earthquake risk. Coastal regions, major metropolitan areas, and zones near active fault lines carry the highest risk. The Japanese government publishes detailed seismic hazard maps showing the probability of earthquakes exceeding magnitude 6 or greater in the next 30 years for each region.