Scale
 Humans Inside Situation Outside Situation
0
 No shaking felt.
-
-
1
 Shaking felt by a few people in a room.
-
-
2
 Shaking felt by many people and some are woken up. Slight movement of hanging objects such as lamps.
-
3
 Shaking felt by most people. Dishes on shelves rattle. Power lines/wires swing slightly.
4
 Gives rise to feelings of fear. Some people try to protect themselves and most are woken up. Considerable swinging of hanging objects and objects on shelves rattle. Unstable objects tip over. Pronounced swinging of power lines/wires. Pedestrians and cyclists feel shaking.
5 lower
 Many people try to protect themselves. Some cannot move freely. Hanging objects shake violently. Utensils and books fall from shelves. Furniture may move. Some window pane breakage. Some unreinforced concrete blocks fall.
5 upper
 Many people cannot move freely and are very frightened. Hanging objects shake violently. Utensils and books fall from shelves. Some drawers fall out. Many unreinforced concrete blocks fall. Vending machines tip over. Difficulty in driving cars.
6 lower
 Difficulty in standing Heavy, unfixed furniture move or tip over. It is hard to open doors. Quite a number of housing tiles and window panes fall down.
6 upper
 Cannot stand upright, only crawl Heavy unfixed furniture move or tip over. Some doors can be unhinged. In many buildings housing tiles and window panes break and fall down. Most unreinforced concrete blocks fall.
7
 Absolutely no control. Most of the furniture is thrown about. In most buildings housing tiles and window panes break and fall down. Some reinforced concrete blocks break.

References

CRESTA Manual, 1996, Swiss Reinsurance Company, Zurich.

Note: Original source unknown. The version in Bolt et al (1975, p11) is only slightly different. Bolt, B.A., Horn W. L., Macdonald, G.A., & Scott, R. F. 1975, Geological Hazards, Springer-Verlag, New York, 328p.