Japan shallow thrust earthquake

 This was a thrust earthquake in the 'backyard', which is normally extension.

The aftershocks have already defined the fault plane.

Since it was some distance out, the Peak Ground Velocity is probably 20 cm/s on land.  That must be some really bad foundation conditions to cause damage at that level.  If there were rock somewhere, the pgv would only be about 5 cm/s.  I'll try to penetrate the horrible web sites to get a pgv, but don't hold your breath.  Japan enjoys its total earthquake isolation.

ps. no chance of a tsunami, since it was a low-displacement thrust.  These produce a high pgv, but little displacement.  It was in very solid rock.

pps.  this is the type of earthquake that is very intense at the source.  It was the same size and type of the Kobe earthquake, but this one was out in the water.

more:  Having fun with the weird Japanese conventions, looks like there is an instrumented spur of land (sandbar?) with 325 cm/s.  The populated sections on mud got 40 cm/s and the firm ground looks to be 10 cm/s.  Distant wave effects were about 2 feet.