The 1946 Nankaido earthquake occurred in the Nankai Trough, a highly active, vigorous, subduction zone where large earthquakes have been recorded since the seventh century, with a recurrence time of 100 to 200 years.
The 1946 Nankaido earthquake occurred in the Nankai Trough. Large earthquakes have been recorded since the seventh century. This was with a recurrence time of 100 to 200 years. The Nankai Trough was a highly active subduction zone. This was vigorous.