The answer to this question is not as straightforward as it may seem. In order to most accurately answer it, we will rephrase the question four different ways:
- For which country do we locate the most earthquakes? Japan. The whole country is in a very active seismic area, and they have the densest seismic network in the world, so they are able to record many earthquakes.
- Which country actually has the most earthquakes? Indonesia is in a very active seismic zone, also, but by virtue of its larger size than Japan, it has more total earthquakes.
- Which country has the most earthquakes per unit area? This would probably be Tonga, Fiji, or Indonesia since they are all in extremely active seismic areas along subduction zones. The sparse seismic instrumentation in those areas doesn't allow us to actually record all the smaller earthquakes.
- Which country has the most catastrophic earthquakes, or which has had the most damage and fatalities? Both China and Iran are in seismically active areas, have very long historical records, and have had many catastrophic earthquakes. Turkey is also worth mentioning in this category.