Tohoku Region

a)Two events of M5.2 and M5.1 occurred in the aftershock region [off the Sanriku coast] of the 1994 M7.5 Sanriku Haruka Offshore earthquake occurred on April 26, and another M5.1 event on April 30. Also, on April 13, there was an M4.8 event from the continental region.
b)On April 26, there was a shallow-focus M4.3 event (maximum seismic intensity: 3) in the Aizu region of Fukushima Prefecture.

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 April 2000