Modified Mercalli Intensity Scale

Intensity Witness Perceptions and Damage
I Felt by very few people; barely noticeable.
II Felt by a few people, especially on upper floors.
III Noticeable indoors, especially on upper floors, but may not be recognized as an earthquake.
IV Felt by many indoors, few outdoors. May feel like heavy truck passing by.
V Felt by almost everyone, some people awakened. Small objects moved. Trees and poles may shake.
VI Felt by everyone. Difficult to stand. Some heavy furniture moved, some plaster falls. Chimneys may be slightly damaged.
VII Slight to moderate damage in well built, ordinary structures. Considerable damage to poorly built structures. Some walls may fall.
VIII Little damage in specially built structures. Considerable damage to ordinary buildings, severe damage to poorly built structures. Some walls collapse.
IX Considerable damage to specially built structures, buildings shifted off foundations. Ground cracked noticeably. Wholesale destruction. Landslides.
X Most masonry and frame structures and their foundations destroyed. Ground badly cracked. Landslides. Wholesale destruction.
XI Total damage. Few, if any, structures standing. Bridges destroyed. Wide cracks in ground. Waves seen on ground.
XII Total damage. Waves seen on ground. Objects thrown up into air.

What Are Earthquake Hazards?