PHIVOLCS Earthquake Intensity Scale (PEIS) [3] [4] [1]
Panukat ng Pagyanig ng Lindol |
|---|
Intensity
Scale | Description | Equivalent to other
seismic scales [5] |
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Modified
Mercalli | Shindo |
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| I | Scarcely perceptible
(Napakahina) | - Perceptible to people under favorable circumstances.
- Delicately balanced objects are disturbed slightly.
- Still water in containers oscillates slowly.
| I | 0 |
| II | Slightly felt
(Bahagyang naramdaman) | - Felt by few individuals at rest indoors.
- Hanging objects swing slightly.
- Still water in containers oscillates noticeably.
| II | 1 |
|---|
| III | Weak
(Mahina) | - Felt by many people indoors especially in upper floors of buildings.
- Vibration is felt like one passing of a light truck.
- Dizziness and nausea are experienced by some people.
- Hanging objects swing moderately.
- Still water in containers oscillates moderately.
| III | 2 |
|---|
| IV | Moderately strong
(Bahagyang malakas) | - Felt generally by people indoors and by some people outdoors.
- Light sleepers are awakened.
- Vibration is felt like a passing of heavy truck.
- Hanging objects swing considerably.
- Dinner, plates, glasses, windows and doors rattle.
- Floors and walls of wood framed buildings creak.
- Standing motor cars may rock slightly.
- Liquids in containers are slightly disturbed.
- Water in containers oscillate strongly.
- Rumbling sound may sometimes be heard.
| IV | 3 |
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| V | Strong
(Malakas) | - Generally felt by most people indoors and outdoors.
- Many sleeping people are awakened.
- Some are frightened, some run outdoors.
- Strong shaking and rocking felt throughout building.
- Hanging objects swing violently. Dining utensils clatter and clink; some are broken.
- Small, light and unstable objects may fall or overturn.
- Liquids spill from filled open containers.
- Standing vehicles rock noticeably.
- Shaking of leaves and twigs of trees are noticeable.
| V | 4 |
| VI | Very strong
(Napakalakas) | - Many people are frightened; many run outdoors.
- Some people lose their balance.
- Motorists feel like driving in flat tires.
- Heavy objects or furniture move or may be shifted.
- Small church bells may ring.
- Wall plaster may crack.
- Very old or poorly built houses and man-made structures are slightly damaged though well-built structures are not affected.
- Limited rockfalls and rolling boulders occur in hilly to mountainous areas and escarpments.
- Trees are noticeably shaken.
| VI | 5- |
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| VII | Destructive
(Mapaminsala) | - Most people are frightened and run outdoors.
- People find it difficult to stand in upper floors.
- Heavy objects and furniture overturn or topple.
- Big church bells may ring.
- Old or poorly built structures suffer considerable damage.
- Some well-built structures are slightly damaged.
- Some cracks may appear on dikes, fish ponds, road surface, or concrete hollow block walls.
- Limited liquefaction, lateral spreading and landslides are observed.
- Trees are shaken strongly.
| VII | 5+ |
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| VIII | Very destructive
(Lubusang mapaminsala) | - People are panicky.
- People find it difficult to stand even outdoors.
- Many well-built buildings are considerably damaged.
- Concrete dikes and foundation of bridges are destroyed by ground settling or toppling.
- Railway tracks are bent or broken.
- Tombstones may be displaced, twisted or overturned.
- Utility posts, towers and monuments may tilt or topple.
- Water and sewer pipes may be bent, twisted or broken.
- Liquefaction and lateral spreading cause man- made structure to sink, tilt or topple.
- Numerous landslides and rockfalls occur in mountainous and hilly areas.
- Boulders are thrown out from their positions particularly near the epicenter.
- Fissures and faults rapture may be observed.
- Trees are violently shaken.
- Water splash or stop over dikes or banks of rivers.
| VIII, IX | 6-, 6+ |
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| IX | Devastating
(Mapanalanta) | - People are forcibly thrown to ground. Many cry and shake with fear.
- Most buildings are totally damaged.
- Bridges and elevated concrete structures are toppled or destroyed.
- Numerous utility posts, towers and monument are tilted, toppled or broken.
- Water sewer pipes are bent, twisted or broken.
- Landslides and liquefaction with lateral spreadings and sandboils are widespread.
- The ground is distorted into undulations.
- Trees are shaken very violently with some toppled or broken.
- Boulders are commonly thrown out.
- River water splashes violently on slops over dikes and banks.
| X, XI | 7 |
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| X | Completely devastating
(Lubusang mapanalanta) | - Practically all man-made structures are destroyed.
- Massive landslides and liquefaction, large scale subsidence and uplifting of land forms and many ground fissures are observed.
- Changes in river courses and destructive seiches in large lakes occur.
- Many trees are toppled, broken and uprooted.
| XII |
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This article incorporates text from this source, which is in the public domain : "Making sense of the PHIVOLCS earthquake intensity levels". Official Gazette of the Republic of the Philippines. Retrieved February 12, 2017.