Seismic Intensity Scale

Intensity Strong Ground Acceleration
Effects on People Effects Indoors Effects Outdoors
0 Micro below 0.8 gal Not felt.    
1 Very minor 0.8-2.5 gal Felt only by a few people at rest, vibrates slightly.    
2 Minor 2.5-8.0 gal Felt by the majority of people. Some awakened from sleeping. Hanging lamps and objects vibrate slightly. Standing vehicles vibrate slightly, similar to being passed by a truck, but only lasts for a short time.
3 Light 8.0-25 gal Felt by nearly everyone, a few frightened. Buildings shake; dishes, windows, and doors shake making sounds; hanging objects shake visibly. Standing vehicles vibrate obviously; electric wires sway gently.
4 Moderate 25-80 gal Many people are quite frightened, looking for safe shelter. Most people are awakened from sleep. Buildings rock noticeably; unstable objects topple over; heavy furniture moves; may cause slight damage. Felt by drivers; electric wires sway obviously, felt by people walking.
5 Strong 80-250 gal Most people are considerably frightened. Walls crack; heavy furniture may overturn. Noticeably felt by drivers; some chimneys and large archways topple over.
6 Very strong 250-400 gal People have trouble walking due to violent rocking. Damage to some buildings; heavy furniture overturns; doors and windows bend. Drivers have trouble steering; sand and clay blasts occur.
7 Great 400 gal and above People move with difficulty due to severe rocking. Severe damage to or collapse of some buildings; almost all furniture moves or falls down. Landslides and faults rupture occur; railway bend; underground lines break.

Before earthquake

During earthquake

After earthquake