A powerful earthquake struck off the coast of northern Japan today, the weather office said, days after an even larger tremor shook the region and injured at least 50.
The Japan Meteorological Agency (JMA), upgrading its initial estimated magnitude of 6.5, also warned that tsunami waves of up to 1m could hit the northern Pacific coastline.
Two 20cm waves had so far been recorded, one in the town of Erimo on the main northern island of Hokkaido at 12.35pm (4.35pm NZT), and another three minutes later in the Aomori region, the agency said.
Broadcaster NHK said there was no obvious change at either of the ports.
The United States Geological Survey also said the quake measured 6.7 and was 130km off the city of Kuji in Iwate prefecture on the main island of Honshu.
Broadcaster NHK said the level of shaking was less than the bigger tremor late on Monday, which knocked items off shelves, tore apart roads, smashed windows and triggered tsunami waves of up to 70cm.
The Nuclear Regulation Authority said there were no immediate signs of abnormalities at the region’s nuclear facilities.
After Monday’s tremor, the JMA had published a rare special advisory warning another quake of similar or greater size was possible during the upcoming week.
The advisory covered the Sanriku area on the northeastern tip of Japan’s main island of Honshu and the northern island of Hokkaido, facing the Pacific.
The region is haunted by the memory of a 9.0-magnitude undersea quake in 2011, which triggered a tsunami that left about 18,500 people dead or missing.
In August 2024, the JMA issued its first special advisory for the southern half of Japan’s Pacific coast, warning of a possible “megaquake” along the Nankai Trough.
The 800km undersea trench is where the Philippine Sea oceanic tectonic plate is “subducting” – or slowly slipping – underneath the continental plate that Japan sits atop.
The Government has said a quake in the Nankai Trough and subsequent tsunami could kill as many as 298,000 people and cause up to US$2 trillion ($3.44t) in damages.
The JMA lifted last year’s advisory after a week but it led to panic-buying of staples such as rice and prompted holidaymakers to cancel hotel reservations.
Japan sits on top of four major tectonic plates along the western edge of the Pacific “Ring of Fire” and is one of the world’s most seismically active countries.
About 1500 jolts occur every year in the archipelago, which is home to about 125 million people.
The vast majority are mild, although the damage they cause varies according to their location and depth below the earth’s surface.
– Agence France-Presse