Event facts
Estimated shaking · MMI X
Extreme. Few structures remain standing. Bridges destroyed, ground waves visible. Underground pipes broken.
MMI is the Modified Mercalli Intensity scale — what people actually feel. This estimate is derived from magnitude alone; real shaking varies with depth, distance and local soil. The official USGS ShakeMap is the authoritative source.
What an M7.4 feels like
Major earthquake. Felt for hundreds of kilometres. Anyone outdoors will be thrown to the ground; difficult to remain standing.
Heavy damage to most buildings, complete collapse of poorly-built structures. Bridges, roads and underground utilities affected.
What a shallow depth means
Shallow earthquakes (under 70 km) release energy close to the surface, so they tend to be felt more strongly and cause more damage than deeper events of the same magnitude. Most earthquakes humans feel are shallow.
Energy released
This earthquake released roughly 8.81e+15 joules of seismic energy — about 139.85× the Hiroshima atomic bomb.
Caveat: bomb energy is concentrated at a single point in microseconds; seismic energy radiates outward through Earth's crust over many seconds. The comparison is for relative scale only.