The Japan Meteorological Agency warned that aftershocks in Kumamoto Prefecture could reach a maximum seismic intensity of seven [1].
This warning is critical because the current seismic activity covers a broad area, increasing the risk of severe damage to infrastructure and residential buildings already weakened by initial shocks.
Shinji Kiyomoto, the agency's official for earthquake and tsunami countermeasures, said the activity zone is spreading across a wide range. He said that depending on the location and magnitude, some areas may experience shaking stronger than what has already occurred.
Kiyomoto pointed to historical precedents to justify the high alert. During the Kumamoto earthquakes in 2016, intensity seven shaking occurred repeatedly on April 14 and April 16 [2]. Because of these past occurrences of successive major shocks, the agency is advising the public to remain vigilant for approximately one week [1].
Recent activity in the region includes a quake with a magnitude of approximately 2.5 and a focal depth of about 10 kilometers, which produced a maximum intensity of two [3]. While this specific event was minor, the agency maintains that the broader pattern of activity remains a concern.
"The activity area is spreading over a considerably wide range," Kiyomoto said. "In the 2016 Kumamoto earthquakes, intensity seven occurred successively on April 14 and 16, so there are examples of successive occurrences in the past. I would like you to be sufficiently careful this time as well."
“The Japan Meteorological Agency warned that aftershocks in Kumamoto Prefecture could reach a maximum seismic intensity of seven.”
The warning reflects a cautious approach based on the 2016 Kumamoto earthquake sequence, where a pattern of multiple high-intensity shocks caused catastrophic damage. By emphasizing the wide activity zone and historical precedents, the Japan Meteorological Agency is attempting to prevent complacency among residents who may believe the primary danger has passed after the initial event.
