Mino–Owari earthquake strikes Japan

Background. The earthquake occurred in the Nōbi Plain, affecting the provinces of Mino and Owari, corresponding to present-day Gifu Prefecture. The region was undergoing industrial transformation and scientific advancement during the Meiji period. Earthquake research had been prioritized in Japan following the 1854 Ansei-Nankai event, leading to the establishment of reporting systems that later facilitated seismological studies.

Geological Impact. The event was caused by the rupture of the Neodani Fault, a left lateral slip fault in central Japan. The earthquake generated many kilometers of visible fault breaks on the Earth's surface. These fault scarps provided scientists with opportunities for field investigations, contributing to an improved understanding of fault structures. The rupture extended across the width of central Honshu.

Seismological Significance. The 1891 earthquake is recognized as the largest recorded inland earthquake in Japan's history. Data from the event, combined with existing reporting systems, allowed seismologist Fusakichi Omori to develop a law of decay for aftershocks. The event's magnitude is estimated at 8.0 surface-wave magnitude, with a moment magnitude of 7.5.