Unexpected recurrence of the tragedy in Kumamoto Prefecture, Japan: the strong earthquake of July 28, 2026

The Uto earthquake (M 6.8, Kumamoto Prefecture, Japan) that occurred on July 28, 2026, was highly unexpected for the scientific community. Slightly more than 10 years prior, a series of three strong Kumamoto events (M 6.0; 6.2; 7.0) occurred a few kilometers north of its epicenter. This “lulled the vigilance” of seismologists, as the duration of the seismic cycle for strong earthquakes is usually much higher. Researchers’ attention was shifted to the east coast of the Japanese archipelago, where a more powerful seismic event is expected in the Nankai Trough area. The authors of this publication had to return to previously obtained results and continue the assessment of movements and deformations in this region up to the present time. The obtained characteristics of crustal movements before strong earthquakes in this area showed that a single local area of high stresses during the interseismic period can be destroyed in stages by several strong events following each other with relatively short interseismic time intervals.