4 (1 to 31 Dec, 1998)
Nationwide M4 (1 to 31 Dec, 1998)
An M5.7 earthquake occurred off the eastern shore of Central Honshu at a depth of about 480km, an M5.5 earthquake occurred offshore of Miyazaki Pref., and an M5.1 earthquake occurred in the coastal waters of Amami Oshima.
Japan Meteorological Agency,Science and Technology Agency