Tohoku Region

a) There was intensified seismic activity, including an M4.1 event, on the east side of the Sanriku (Akita-Iwate-Miyagi) area ocean trench axis.
b) An M5.0 earthquake occurred on 9 January near the border of the Pacific Plate offshore of Fukushima Pref.
c) An M4.2 earthquake occurred on 10 January in northern Miyagi Pref. This earthquake occurred within the area of seismic activity in 1996 near the border of Akita, Miyagi, and Yamagata Prefs.

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 January 2000