Earthquake in Suruga Bay on August 1

On August 1, 2011 at 23:58 (JST), there was a M6.2 earthquake (maximum seismic intensity 5 Lower) at a depth of 23 km in Suruga Bay. The focal mechanism (CMT solution) showed a reverse fault with a compression axis in an N-S direction. This event occurred within the Philippine Sea plate. This event caused damage with 13 injured persons and 15 partially harmed houses (Shizuoka prefecture). There were 4 aftershocks with a seismic intensity 1 by 05:00 on August 2, but the aftershock activity has gradually been subsiding.
For the seismic activity since October 1997, in the vicinity of the recent event (Area c), there was a M6.5 earthquake (maximum seismic intensity 6 Lower) on August 11, 2009, and it caused damage with one fatality and 319 injured people (Fire and Disaster Management Agency).
For the seismic activity since August 1923, in the area around the recent event (Area d), there have sometimes been earthquakes of M6.0 or over.

Japan Meteorological Agency
[Seismic Activity for August 2011 (September 9, 2011)]