Earthquake in Central Nagano Prefecture on June 30 (Past Activities)

For the seismic activity since August 1923, in the area around the recent event (Area b), there had been no earthquake over M5.0 until the recent event occurred.
There have been earthquakes over M6.0 outside Area b, and the 1984 Nagano-ken Seibu Earthquake that occurred on September 14, 1984 caused damage with 29 fatalities, 10 injured persons, 14 totally destroyed houses and 73 half destroyed houses (Comprehensive Bibliography of Destructive Earthquakes in Japan, Latest Edition).

For the seismic activity since the Edo period, there have been earthquakes over M6.0 in the area around the recent event. According to Comprehensive Bibliography of Destructive Earthquakes in Japan, Latest Edition, the following seismic damage is known.
- M6.2 earthquake on April 28, 1714
100 fatalities, 37 injured persons, 594 damaged houses
- M6.3 earthquake on August 14, 1725
Collapsed stone walls and embankments of Takatou Castle (Damage was unknown outside castle), collapsed stone walls of Suwa-Takashima Castle, landslides
- M6.7 earthquake on July 23, 1791
Collapsed moats of Matsumoto Castle, damaged houses
- M7.4 earthquake on May 8, 1847 (Zenkoji Earthquake)
8,174 fatalities, 4,116 injured people

Japan Meteorological Agency
[Seismic Activity for June 2011 (July 11, 2011)]