Tohoku Region

a) On July 31st, there was activity including an M5.2 event occurring in conjunction with the subduction of the Pacific Plate in the sea off Sanriku (off the coast of Iwate Prefecture).
b) On July 20th, there was an M5.2 event occurring in conjunction with the subduction of the Pacific Plate in the sea off Sanriku (off the coast of Miyagi Prefecture).
c) On July 1st, there was an M5.1 event occurring in conjunction with the subduction of the Pacific Plate in the sea off the coast 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 July 2000