April 8, 2011
Earthquake Research Committee,
Headquarters for Earthquake Research Promotion
* On April 7 at 23:32 (JST), there was a M7.1 earthquake at a depth of approximately 65km, off-shore of Miyagi prefecture. This event had a maximum seismic intensity 6 Upper observed in Miyagi prefecture, and caused damage. After this event, there was an earthquake with seismic intensity 3 (as of 14 o’clock, April 8).
* The focal mechanism of this event showed a reverse fault with a compression axis in a WNW-ESE direction. The focal depth was deep and the aftershock distribution showed a southeast dip. In view of them, this event did not occur on the plate boundary, but occurred within the Pacific plate.
* This event occurred within the aftershock area of the 2011 off the Pacific Coast of Tohoku Earthquake, and there is a continuing fear that large aftershocks will hereafter occur.