Tohoku Region

a) An M5.1 earthquake occurred on 16 February on the east side of the marine-trench axis offshore of Fukushima Pref.
b) There was clustered seismic activity with a maximum M4.7 earthquake on 11 February in the vicinity of the border of Iwate, Miyagi, and Akita Prefs. [Southern Iwate Prefecture] (maximum intensity: 3).
Furthermore, although it is outside our time frame, a shallow M3.8 earthquake occurred on 7 March in northern Iwate Pref.
Note: Within square brackets ([ ]) is the epicenter place name used by the Meteorological Agency in its information releases.

Note:
M=magnitude
N: total number of events in the figure
depth=depth of hypocenter
UND=Earthquakes of less than M1.0 and earthquakes whose magnitude was not recorded.
The key to the symbols shows on the left the size of an earthquake and on the right the depth of the hypocenter.

Japan Meteorological Agency,Science and Technology Agency

Seismic Activity in Japan February 2000