Following a magnitude-7.5 powerful earthquake that struck Aomori Prefecture in northern Japan on the night of Monday (December 8), authorities issued tsunami warnings for Pacific coastal areas including Hokkaido, Miyagi Prefecture, Iwate Prefecture and Fukushima Prefecture. Aftershocks continued to jolt the Aomori region the next day. For the first time, authorities issued a subsequent earthquake warning for offshore areas such as Hokkaido, alerting residents to the possibility of stronger earthquakes in the coming week.

According to the Japan Meteorological Agency (JMA), the quake’s epicenter was located in the offshore area east of Aomori Prefecture, with a focal depth of 54 kilometers and a magnitude of 7.5 on the Richter scale. This marks the first time such a strong earthquake has been recorded in the Aomori region since seismic monitoring equipment was installed there in 1996.

Hachinohe City in Aomori Prefecture bore the brunt of the disaster, where a 3-meter-tall stone gate at a local shrine collapsed. In an interview on Tuesday (December 9), a woman in her 70s living nearby said, “The tremor last night was unlike anything I’ve ever experienced. I often clean the shrine steps. If the quake had hit during the day, I wouldn’t have survived.”

According to official sources, the earthquake struck at 11:15 p.m. local time on Monday (10:15 p.m. Singapore time the same day), injuring at least 50 people. Tsunami warnings were immediately issued for Aomori Prefecture and Hokkaido, prompting the emergency evacuation of 110,000 residents. With temperatures plummeting in December, some elderly people slipped and got injured on icy roads while heading to evacuation shelters.

After the quake, water and power supplies were cut off across Aomori. On the following day, more than 40 primary and secondary schools in the affected areas suspended classes; the Shinkansen bullet trains heading to Tohoku also halted services for 16 hours to inspect tracks for damage.

According to the Japan Atomic Energy Agency, water overflowed from a nuclear fuel storage pool at a nuclear fuel reprocessing plant in Aomori Prefecture after the quake, but no contaminated water leaked outside the plant premises. No abnormalities were detected at other nuclear power facilities in Hokkaido and the Tohoku region.

Hours after the earthquake hit, Japanese authorities issued the first-ever “Subsequent Earthquake Warning for the Offshore Area of Sanriku, Hokkaido”, warning residents of the potential for more powerful earthquakes over the next week. The alert highlighted an increased likelihood of major earthquakes along the Japan Trench and Kuril Trench. Authorities estimated a 1% probability of a magnitude-8 or higher earthquake occurring within seven days. The warning covered 182 municipalities, ranging from Hokkaido to Chiba Prefecture in the Kanto region. The alert will be lifted at midnight on the 16th if no further seismic activity occurs.

This early warning system was established in December 2022, and this marks its first activation by authorities.

At a press conference, Morikubo Tsukasa, Earthquake Advisor to the Cabinet Office, emphasized, “As this is the first time such a warning has been issued, it may cause anxiety among the public, but it does not mean a major earthquake is certain to occur.”

What would happen if a major earthquake were to strike again? Satoshi Harada, Director of the Earthquake and Volcano Technology Research Division at the JMA, stated, “In the worst-case scenario, it could be similar to the 2011 Great East Japan Earthquake.”

Citing official simulation data, Japanese media reported that a super-quake along the Japan Trench and Kuril Trench could trigger 30-meter-high tsunamis in parts of Hokkaido and Iwate Prefecture, potentially killing nearly 200,000 people in the worst-case scenario. However, authorities stressed that prompt evacuation and other measures could reduce human casualties by approximately 80%.

Following a magnitude-7.5 powerful earthquake that struck Aomori Prefecture in northern Japan on the night of Monday (December 8), authorities issued tsunami warnings for Pacific coastal areas including Hokkaido, Miyagi Prefecture, Iwate Prefecture and Fukushima Prefecture. Aftershocks continued to jolt the Aomori region the next day. For the first time, authorities issued a subsequent earthquake warning for offshore areas such as Hokkaido, alerting residents to the possibility of stronger earthquakes in the coming week.

According to the Japan Meteorological Agency (JMA), the quake’s epicenter was located in the offshore area east of Aomori Prefecture, with a focal depth of 54 kilometers and a magnitude of 7.5 on the Richter scale. This marks the first time such a strong earthquake has been recorded in the Aomori region since seismic monitoring equipment was installed there in 1996.

Hachinohe City in Aomori Prefecture bore the brunt of the disaster, where a 3-meter-tall stone gate at a local shrine collapsed. In an interview on Tuesday (December 9), a woman in her 70s living nearby said, “The tremor last night was unlike anything I’ve ever experienced. I often clean the shrine steps. If the quake had hit during the day, I wouldn’t have survived.”

According to official sources, the earthquake struck at 11:15 p.m. local time on Monday (10:15 p.m. Singapore time the same day), injuring at least 50 people. Tsunami warnings were immediately issued for Aomori Prefecture and Hokkaido, prompting the emergency evacuation of 110,000 residents. With temperatures plummeting in December, some elderly people slipped and got injured on icy roads while heading to evacuation shelters.

After the quake, water and power supplies were cut off across Aomori. On the following day, more than 40 primary and secondary schools in the affected areas suspended classes; the Shinkansen bullet trains heading to Tohoku also halted services for 16 hours to inspect tracks for damage.

According to the Japan Atomic Energy Agency, water overflowed from a nuclear fuel storage pool at a nuclear fuel reprocessing plant in Aomori Prefecture after the quake, but no contaminated water leaked outside the plant premises. No abnormalities were detected at other nuclear power facilities in Hokkaido and the Tohoku region.

Hours after the earthquake hit, Japanese authorities issued the first-ever “Subsequent Earthquake Warning for the Offshore Area of Sanriku, Hokkaido”, warning residents of the potential for more powerful earthquakes over the next week. The alert highlighted an increased likelihood of major earthquakes along the Japan Trench and Kuril Trench. Authorities estimated a 1% probability of a magnitude-8 or higher earthquake occurring within seven days. The warning covered 182 municipalities, ranging from Hokkaido to Chiba Prefecture in the Kanto region. The alert will be lifted at midnight on the 16th if no further seismic activity occurs.

This early warning system was established in December 2022, and this marks its first activation by authorities.

At a press conference, Morikubo Tsukasa, Earthquake Advisor to the Cabinet Office, emphasized, “As this is the first time such a warning has been issued, it may cause anxiety among the public, but it does not mean a major earthquake is certain to occur.”

What would happen if a major earthquake were to strike again? Satoshi Harada, Director of the Earthquake and Volcano Technology Research Division at the JMA, stated, “In the worst-case scenario, it could be similar to the 2011 Great East Japan Earthquake.”

Citing official simulation data, Japanese media reported that a super-quake along the Japan Trench and Kuril Trench could trigger 30-meter-high tsunamis in parts of Hokkaido and Iwate Prefecture, potentially killing nearly 200,000 people in the worst-case scenario. However, authorities stressed that prompt evacuation and other measures could reduce human casualties by approximately 80%.