# Central Weather Administration seismic intensity scale

The Central Weather Administration seismic intensity scale (Chinese: 交通部中央氣象署地震震度分級, CWASIS) is a seismic intensity scale used in Taiwan. It was established by the Central Weather Administration.

## Scale overview

Seismic Intensity Scale :
| Intensity Level (震度分級) | Intensity Level (震度分級) | Intensity Level (震度分級) | Strong Ground Acceleration (cm/s$^2$,gal) | Ground Speed (cm/s) | What People Feel | Effects Indoors | Effects Outdoors |
| 0 | 0 | Undetectable (無感) | below 0.8 gal | | Imperceptible to humans | | |
| 1 | 1 | Slight (微震) | 0.8-2.5 gal | | People may feel slight shaking when motionless | | |
| 2 | 2 | Weak (輕震) | 2.5-8.0 gal | | Most people will feel shaking, and some sleepers may wake up | Light shaking of dangling objects such as lamps | Stationary vehicles shake slightly, similar to when a truck passes by, but only for a short time |
| 3 | 3 | Light (弱震) | 8.0-25 gal | | Almost everyone will feel shaking, and some may experience fear | Houses shake; bowls, plates, doors, windows etc. make noise; dangling objects swing | Stationary vehicles shake visibly; power lines sway slightly |
| 4 | 4 | Moderate (中震) | 25-80 gal | less than 15 cm/s | Will cause a considerable degree of fear; some people will look for shelter, and almost all sleepers will wake up | Houses shake violently; objects tumble; heavy furniture moves; slight damage may occur | Vehicle drivers feel slight shaking; power lines sway visibly; pedestrians also feel shaking |
| 5 | 5 Lower | Strong (強震) | 80 gal and above | 15–30 cm/s | Most people are frightened and panic | Some walls crack; heavy furniture may be overturned | Vehicle drivers feel obvious shaking; some signboards and chimneys fall or collapse |
| 5 | 5 Upper | Strong (強震) | 80 gal and above | 30–50 cm/s | Almost everyone is frightened and panics, and has difficulty walking | Large quantities of unsecured items tumble and fall; furniture moves or is overturned; some doors and windows become twisted; some walls crack; a small number of houses with poor seismic resistance may be damaged or collapse | Wall tiles fall from some buildings; rockfalls occur in mountainous areas; liquefaction may occur in soft soil; utilities and/or communications may be interrupted in some areas; a small number of brick walls with poor seismic resistance may be damaged or collapse |
| 6 | 6 Lower | Violent (烈震) | 80 gal and above | 50–80 cm/s | Violent shaking makes it difficult to remain standing | Some buildings are damaged; heavy furniture is overturned; doors and windows twist | Drivers have difficulty driving; soil liquefaction is seen |
| 6 | 6 Upper | Violent (烈震) | 80 gal and above | 80–140 cm/s | Violent shaking makes it almost impossible to stand | Lots of furniture moves violently or is overturned; doors and windows become twisted; some houses with poor seismic resistance may be damaged or collapse, and even houses with better seismic resistance may also be damaged | Some ground surfaces crack; landslides may occur in mountainous areas; liquefaction occurs in soft soil; utilities and/or communications may be interrupted on a large scale |
| 7 | 7 | Extreme (劇震) | 80 gal and above | 140 cm/s and above | Violent shaking make voluntary action impossible | Some buildings are seriously damaged or collapse; almost all furniture moves a long distance or tumbles | Landslides occur and fissures appear; railroad tracks are twisted; underground pipelines are damaged |