PHIVOLCS Earthquake Intensity Scale (PEIS)[3][4][1] Panukat ng Pagyanig ng Lindol
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Intensity Scale
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Description
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Equivalent to other seismic scales[5]
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Modified Mercalli
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Shindo
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I
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Scarcely perceptible (Napakahina)
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- Perceptible to people under favorable circumstances.
- Delicately balanced objects are disturbed slightly.
- Still water in containers oscillates slowly.
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I
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0
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II
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Slightly felt (Bahagyang naramdaman)
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- Felt by few individuals at rest indoors.
- Hanging objects swing slightly.
- Still water in containers oscillates noticeably.
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II
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1
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III
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Weak (Mahina)
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- 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.
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III
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2
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IV
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Moderately strong (Bahagyang malakas)
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- 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.
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IV
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3
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V
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Strong (Malakas)
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- 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.
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V
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4
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VI
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Very strong (Napakalakas)
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- 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.
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VI
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5-
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VII
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Destructive (Mapaminsala)
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- 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.
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VII
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5+
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VIII
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Very destructive (Lubusang mapaminsala)
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- 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.
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VIII, IX
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6-, 6+
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IX
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Devastating (Mapanalanta)
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- 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.
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X, XI
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7
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X
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Completely devastating (Lubusang mapanalanta)
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- 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.
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XII
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