Tsunami advisory lifted after 6.7 quake rattles northern Japan

Japan’s weather authorities have lifted a tsunami advisory along the Pacific coast of northern Japan after an offshore earthquake briefly raised concerns of rising seas, national broadcaster NHK reported.

The magnitude 6.7 quake struck off the coast of Aomori Prefecture at 11:44am local time (02:44 GMT) on Friday, at a depth of about 20km, according to the Japan Meteorological Agency (JMA). The advisory was issued as a precaution and later lifted after officials confirmed there was no significant danger.

The JMA recorded two small waves, each about 20 centimetres high, in the town of Erimo on the northern island of Hokkaido at 12:35pm, followed by another similar wave minutes later in the Aomori region. NHK said there were no noticeable changes in port conditions.

Japan’s Nuclear Regulation Authority also reported no abnormalities at nuclear facilities in the affected area.

Friday’s tremor came just days after a more powerful magnitude 7.5 earthquake struck the same region on Monday, injuring at least 50 people, damaging roads and buildings, and generating tsunami waves of up to 70 centimetres. NHK noted that the shaking from the latest quake was noticeably weaker than Monday’s event.

In the aftermath of that earlier earthquake, the JMA issued a rare special advisory, warning residents from Hokkaido in the north to Chiba, east of Tokyo, to remain alert for the possibility of another strong quake within a week.

Northern Japan remains deeply marked by the memory of the 2011 magnitude 9.0 undersea earthquake off the northeast coast, which unleashed a devastating tsunami that killed or left missing about 18,500 people.

More broadly, Japan has been on edge over seismic risks along its Pacific coast. Earlier this year, the JMA issued its first special advisory for the southern half of the country, warning of a potential “megaquake” along the Nankai Trough. Government estimates suggest such a disaster, combined with a tsunami, could kill up to 298,000 people and cause as much as $2 trillion in damage.