MMIIntensity Typical effects
1 unnoticeableBarely sensed only by a very few people.
2 unnoticeableFelt only by a few people at rest in houses or on upper floors.
3 weak Felt indoors as a light vibration. Hanging objects may swing slightly.
4 light Generally noticed indoors, but not outside, as a moderate vibration or jolt. Light sleepers may be awakened. Walls may creak, and glassware, crockery, doors or windows rattle.
5 moderate Generally felt outside and by almost everyone indoors. Most sleepers are awakened and a few people alarmed. Small objects are shifted or overturned, and pictures knock against the wall. Some glassware and crockery may break, and loosely secured doors may swing open and shut.
6 strong Felt by all. People and animals are alarmed, and many run outside. Walking steadily is difficult. Furniture and appliances may move on smooth surfaces, and objects fall from walls and shelves. Glassware and crockery break. Slight non-structural damage to buildings may occur.
7 severe General alarm. People experience difficulty standing. Furniture and appliances are shifted. Substantial damage to fragile or unsecured objects. A few weak buildings are damaged.
8 extreme Alarm may approach panic. A few buildings are damaged and some weak buildings are destroyed.
9 extreme Some buildings are damaged and many weak buildings are destroyed.
10 extreme Many buildings are damaged and most weak buildings are destroyed.
11 extreme Most buildings are damaged and many buildings are destroyed.
12 extreme All buildings are damaged and most buildings are destroyed.