Earthquake under the Suruga Bay on August 11 (M6.5)

On August 11, 2009 at 05:07 (JST) there was a M6.5 earthquake at a depth of 23km under Suruga Bay (maximum seismic intensity 6 Lower). This earthquake caused damage with 68 injured people in the area centered on Shizuoka prefecture (Fire and Disaster Management Agency, as of 12:15 on August 11). The focal mechanism had a compression axis in a NNE-SSW direction. The aftershock activity has been declining. (The largest aftershock as of 18:30 on August 11 was the M4.3 (preliminary) at 18:09.) Judging from the source depth, the focal mechanism, and the aftershock distribution, it is thought that this event occurred within the Philippine Sea plate.
Since October 1997, seismic activity in this vicinity (Area b) had been at a low level compared to seismicity in the neighboring area, with occasional M2–3 class events.

For seismic activity since August in 1923, in the area near this event (Area c), in 1935 and 1965, Shizuoka Earthquakes occurred in the onshore area to the northwest of the recent earthquake.

*The hypocentral data for August 11 is partially unprocessed.

Japan Meteorological Agency
[Seismic Activity under the Suruga Bay on August 11, 2009 (August 11, 2009)]