7.1-Magnitude Quake Hits Off Southern Japan

A powerful earthquake struck off Japan's southern coast on Thursday, triggering a tsunami advisory. Residents were urged to stay away from the coastline, but there were no immediate reports of injuries or major damage. The Japan Meteorological Agency said the quake registered a preliminary magnitude of 7.1 and was centered off the eastern coast of Japan's southern main island of Kyushu at a depth of about 18.6 miles. The agency said tsunami waves of up to 50 centimeters—1.6 feet—were detected along parts of Kyushu's southern coast and the nearby island of Shikoku about a half-hour after the quake struck, the AP reports.

The US Geological Survey said the 7.1-magnitude quake came less than a minute after a 6.9-magnitude quake, the New York Times reports. Public broadcaster NHK reports that no problems have been detected at nuclear power plants in the region. The quake most strongly shook Nichinan city and nearby areas in Miyazaki prefecture on Kyushu island. Seismologists were holding an emergency meeting to analyze whether the quake had affected the nearby Nankai Trough, the source of past devastating earthquakes. This story has been updated with new developments. (More Japan earthquake stories.)