Central Weather Administration seismic intensity scale
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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
[edit]Intensity (震度分級) |
Strong Ground Acceleration (cm/s2,gal) |
Ground Speed (cm/s) |
Effects on People | Effects Indoors | Effects Outdoors | ||
---|---|---|---|---|---|---|---|
0 | Micro (無感) |
below 0.8 gal | Not felt. | ||||
1 | Very minor (微震) |
0.8-2.5 gal | Felt only by a few people at rest, vibrates slightly. | ||||
2 | Minor (輕震) |
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 (弱震) |
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 (中震) |
25-80 gal | less than 15 cm/s | 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 | 5- | Strong (強震) |
80 gal and above | 15–30 cm/s | Most people are considerably frightened. | Walls crack; heavy furniture may overturn. | Noticeably felt by drivers; some chimneys and large archways topple over. |
5+ | 30–50 cm/s | ||||||
6 | 6- | Very strong (烈震) |
50–80 cm/s | 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. | |
6+ | 80–140 cm/s | ||||||
7 | Great (劇震) |
140 cm/s 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. |
References
[edit]- ^ "交通部中央氣象局有感地震報告發布作業要點" (PDF). 2019-12-11. Archived (PDF) from the original on 2019-12-11. Retrieved 2021-06-02.
- ^ 交通部中央氣象局新聞稿
- ^ 地震百問 震度 - Central Weather Administration