5 km SSE of ?iso, Japan

A magnitude 8.0 earthquake — a major event — struck near 5 km SSE of ?iso, Japan on September 1, 1923, at a shallow depth of about 15 km. An earthquake this size would have been felt strongly across the surrounding region; shallow earthquakes release their energy close to the surface, so they tend to cause the strongest shaking and the most damage. Shallow magnitude 8.0 events near a coastline can also pose a tsunami risk. Casualties, damage and the recovery depend on local building standards, population and distance from the epicentre — the news coverage, references and photos below capture what happened on the ground.