A screenshot of a TV broadcast showing “Tsunami warning issued” for coastal regions of northern Japan

 A map of the earthquake epicentre and tsunami-alert zones — off the coast of Aomori Prefecture, with warnings covering coastal areas of Hokkaido, Aomori and Iwate Prefecture 

• The quake struck late on Monday (local time) off the northeastern coast of Japan, near Aomori Prefecture in northern Japan. 

• According to United States Geological Survey (USGS), the magnitude was 7.6.

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  The quake’s epicentre was undersea — roughly 80 km off the coast, at a depth of about 50–53 km. The shaking was strong: the quake registered “upper 6” on Japan’s seismic intensity scale (which goes up to 7) in some areas — strong enough to make standing difficult.

Because of that, the Japan Meteorological Agency (JMA) issued tsunami warnings for coastal prefectures including Hokkaido, Aomori and Iwate Prefecture; and tsunami advisories for coastal areas of Miyagi Prefecture and Fukushima Prefecture. 

Officials warned that tsunami waves could reach up to around 3 metres (10 feet) — though later that worst-case scenario did not fully materialize.

What actually happened afterwards

• Early measurements recorded tsunami waves of around 40–50 cm, with some spots reporting up to 70 cm. For example, about 50 cm waves were seen at a port in Iwate prefecture, while other coastal areas saw varying smaller surges. 

• Following the initial panic, the tsunami warnings were later downgraded to advisories, and finally lifted, after the observed waves remained relatively small.

Impact: Injuries, Evacuations, and Disruptions

• At least 20–30 people were reported injured (some media say 23) — mostly due to falling objects or debris during shaking. No confirmed deaths so far.

• Around 90,000 people in the affected coastal zones were ordered to evacuate, as a precaution. 

• Some power outages, suspension of services at coastal facilities (for example an LNG terminal), and a halt in certain industrial operations were reported. Nuclear power plants in the region reportedly saw no anomalies so far.