Japan Issues Continued Megaquake Advisory After Series of Tremors

Miyazaki Prefecture, Japan — Japan’s Meteorological Agency is maintaining a heightened alert for a potential mega-earthquake in the Nankai Trough, having first issued this rare advisory on Thursday following significant seismic activity along the Pacific coast. This announcement comes in the wake of a magnitude 7.1 earthquake near Miyazaki Prefecture, quickly followed by another tremor of 6.8 magnitude affecting northern and northeastern regions of Japan.

According to Philippines News Agency, which issued the original alert after Thursday’s seismic event, there have been no observed changes in the crustal strain that would typically indicate an imminent mega-earthquake. However, the frequency and intensity of recent tremors have led the agency to caution that the risk of a severe quake in the Nankai Trough is currently elevated. The Nankai Trough, which extends from southwestern through to central Japan, could experience aftershocks or related seismic activity with a maximum seismic intensity of lower 6, potentially continuing over the next week.

The advisory, a first of its kind for the regions around the Nankai Trough, aims to urge local governments and citizens to remain vigilant. While the JMA clarified that the advisory does not guarantee an earthquake within a specific timeframe, it has prompted 707 municipalities across 29 prefectures—from Tokyo to Okinawa—to review and enhance their disaster preparedness plans.

Further, the government has issued specific guidance for vulnerable populations, including households with infants, elderly individuals, and people with disabilities, recommending they consider voluntary evacuation as a precautionary measure.