Hokkaido Region

a)There was seismic activity in the Soya Kaikyo sea, in which a shallow M4.3 event on 15 May was the strongest event.
b)There was a deep (340 km) M5.0 event in the Soya Kaikyo sea on 8 May.

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 May 2000