|
Mercalli Intensity |
Magnitude |
Witness Observations |
|
I |
1 to 2 |
Felt by very few people; barely noticeable. |
|
II |
2 to 3 |
Felt by a few people, especially on upper floors. |
|
III |
3 to 4 |
Noticeable indoors, especially on upperfloors, but may not be recognized as an earthquake. |
|
IV |
4 |
Felt by many indoors, few outdoors. May feel like heavy truck passing by. |
|
V |
4 to 5 |
Felt by almost everyone, some people awakened. Small objects moved. Trees and poles may shake. |
|
VI |
5 to 6 |
Felt by everyone. Difficult to stand. Some heavy furniture moved, some plaster falls. Chimneys may be slightly damaged. |
|
VII |
6 |
Slight to moderate damage in well built, ordinary structures. Considerable damage to poorly built structures. Some walls may fall. |
|
VIII |
6 to 7 |
Little damage in specially built structures. Considerable damage to ordinary buildings, severe damage to poorly built structures. Some walls collapse. |
|
IX |
7 |
Considerable damage to specially built structures, buildings shifted off foundations. Ground cracked noticeably. Wholesale destruction. Landslides. |
|
X |
7 to 8 |
Most masonry and frame structures and their foundations destroyed. Ground badly cracked. Landslides. Wholesale destruction. |
|
XI |
8 |
Total damage. Few, if any, structures standing. Bridges destroyed. Wide cracks in ground. Waves seen on ground. |
|
XII |
8 or greater |
Total damage. Waves seen on ground. Objects thrown up into air. |