The Japan Meteorological Agency issued a warning to remain vigilant for earthquakes of up to seismic intensity seven for the next week [1].

This alert follows a magnitude 7.1 earthquake [2] that struck Kumamoto Prefecture on July 28, 2026 [1]. The warning is critical because the agency believes aftershocks could be as strong as the main shock, particularly during the second and third days following the event [1, 4].

The quake produced a maximum seismic intensity of seven [1] in Ueki City and Hikawa Town [9]. These areas are located near the Futagawa and Hinagu fault zones [3]. The hypocenter was recorded at a shallow depth of 10 km [3].

Casualties were reported at the Aeon Mall Kumamoto, where two people died [5]. Reports on further injuries vary, with one source stating one person was in cardiac arrest [5], while another reported three people in cardiac arrest [7].

Shinji Kiyomoto of the Japan Meteorological Agency said the activity zone is spread across a considerably wide area. He said that depending on where a quake occurs and its scale, some locations may experience shaking stronger than the initial event [6].

Agency officials said that caution is necessary for earthquakes of a similar magnitude over the coming week [4]. This precautionary stance is based on patterns observed during the 2016 Kumamoto events, where shallow depths and wide activity zones led to significant aftershocks [1, 3].

“Caution is necessary for earthquakes of a similar magnitude over the coming week.”

The Japan Meteorological Agency's specific warning for the 48-to-72-hour window suggests a high risk of 'doublet' earthquakes or strong aftershocks. By referencing the 2016 Kumamoto sequence, officials are signaling that the current seismic activity may not be a single event but the start of a volatile period, necessitating immediate structural safety checks and public readiness in the Futagawa and Hinagu fault regions.