TOKYO - An earthquake with a preliminary magnitude of 7.3 struck off Japan's northeastern region late Saturday, injuring more than 50 people and causing widespread blackouts, but there are no tsunami threats or abnormalities at nuclear plants.The quake occurred at 11:07 p.m. with the focus about 55 kilometers below the sea surface off the coast of Fukushima Prefecture, according to the Japan Meteorological Agency. The temblor was also felt in Tokyo.It registered upper 6 on Japan's seismic intensity scale of 7 in parts of Fukushima and Miyagi prefectures, which were devastated by a catastrop…READ FULL ARTICLE