Govt Issues Subsequent Earthquake Advisory Following M7.5 Earthquake Off Aomori Prefecture, Warning Another Megaquake May Follow

The Japan News

13:24 JST, December 9, 2025

The government has issued a subsequent earthquake advisory, warning that another megaquake may follow the magnitude 7.5 earthquake that struck off the coast of Aomori Prefecture on late Monday night.

This is the first time that the subsequent earthquake advisory system has been utilized since it was launched in December 2022.

According to the Japan Meteorological Agency, a large earthquake occurring in the aftermath of a magnitude 7.0 or greater earthquake in or around the area off the coast of Hokkaido and the Sanriku region, including Aomori Prefecture, is considered to be a relatively high possibility.

The agency said the probability, based on worldwide records, is about 1/100.

The areas covered by the advisory extend across 182 municipalities from Hokkaido to Chiba Prefecture.

Under the advisory, the agency urges residents in those municipalities to take the following measures: Be ready to evacuate even at night; keep an emergency kit on hand; ensure access to emergency information; be ready for collapses caused by earthquakes; and double check that everyday preparations have been made.

Disaster Preparedness / Post-Quake Congestion Could Cause Secondary Disasters; Crowds, Loss of Phone Signal Issues to be Aware of 

What happens when the electricity goes out in a nighttime quake? 

How to protect children at preschool facilities after a major tsunami warning