A quake big enough to shake houses, about 100 miles from the
broken Fukushima Daiichi nuclear reactors.
Details from Japan Meteorological Agency:

Earthquake Information (Information on seismic intensity at each site)
Issued at 21:10 JST 17 Apr 2013

Occurred at (JST)	Latitude (degree)	Longitude (degree)	Depth	Magnitude	Region Name
21:03 JST 17 Apr 2013	38.5N	141.6E	60 km	5.8	Miyagi-ken Oki

-jsq

PS: Owed to Masaichi Shiozaki.