Major earthquake off Japan's north coast prompts tsunami alert (7.7)

Tokyo — A powerful earthquake struck off the northern Japanese coast Monday, prompting the Japan Meteorological Agency (JMA) to issue a tsunami alert for a wide section of coastline, though waves of only about three feet were observed and the emergency appeared to be easing. The quake registered a preliminary magnitude of 7.5 but was later upgraded to 7.7. It occurred off the coast of Sanriku in northern Japan at around 4:53 p.m. (2:53 a.m. Eastern on Sunday), at a depth of about 6 miles below the sea surface, the agency said....