Earthquake Off-shore East of Aomori Prefecture on April 29
On April 29, 2008, at 14:26 (JST) there was a M5.7 earthquake off-shore east of Aomori prefecture (depth of 62km, maximum seismic intensity 4). The focal mechanism showed a reverse fault with a compression axis in a WNW-ESE direction. This event occurred at the boundary between the Pacific and the continental plates. The aftershock activity subsided within two days.
For the seismic activity since October 1997, in the vicinity of the recent event (Area b), earthquakes over M5.0 have sometimes occurred, such as the M5.3 event on May 19, 2007 (depth of 68km, maximum seismic intensity 4).
For the seismic activity since August 1923, in the area near the recent event (Area c), M6 class earthquakes have sometimes occurred, such as the M6.6 event on October 18, 1951 (maximum seismic intensity 4). In addition, in the neighboring area, earthquakes over M7.0 have occurred, such as the 1968 Tokachi Earthquake (M7.9) and the 1994 Far-offshore Sanriku Earthquake (M7.6).
Japan Meteorological Agency
[Seismic Activity for April 2008 (May 12, 2008)]