The document outlines the PHIVOLCS Earthquake Intensity Scale (PEIS), which categorizes earthquake effects from 'scarcely perceptible' to 'completely devastating'. Each intensity level describes the observable effects on people, structures, and the environment, ranging from minimal disturbances to total destruction. The scale provides a thorough understanding of how various intensities impact both people and infrastructure during seismic events.

1. PHIVOLCS Earthquake Intensity Scale (PEIS)[2]
Intensity
Scale
Description
Equivalent to other
seismic scales[3]
Modified
Mercalli
Shindo
I
Scarcely
perceptible
 Delicatelybalanced objects are disturbed slightly.
 Still water in containers oscillates slowly.
I 0
II Slightly felt
 Felt by few individuals atrest indoors.
 Hanging objects swing slightly.
 Still water in containers oscillates noticeably.
II 1
III Weak
 Felt by many people indoors,especiallyin upper floors.
 Hanging objects swing moderately.
 Still water in containers oscillates moderately.
 Feels like a lighttruck passing by.
III 2
IV
Moderately
strong
 Felt generallyby people indoors and by some people outdoors.
 Hanging objects swing considerably.
 Motorcars may rock slightly.
 Liquids in containers are slightlydisturbed.
 Water in containers oscillates strongly.
 A rumbling sound maysometimes be heard.
 Feels like a heavy truck passing by.
IV 2–3
V Strong
 Felt by mostpeople indoors and outdoors.
 A strong shaking and rocking is felt throughoutbuilding.
 Hanging objects swing violently.
 Small,light,and unstable objects mayfall or overturn.
 Liquids spill from filled open containers.
 Vehicles rock noticeably.
 Leaves and twigs of trees shake.
V 3
VI Very Strong
 Furniture and other heavy objects are displaced.
 Wall plaster maycrack.
 People may lose balance.
 Small church bells mayring.
 If on the road,it may feel like driving with flat tires.
 Very old or poorly built houses and man-made structures are slightly
damaged though well-builtstructures are notaffected.
 Limited rockfalls and rolling boulders occur in hillyto mountainous areas
and escarpments.
 Trees shake .
VI
4
VII Destructive
 Heavy objects and furniture overturn or topple.
 Difficulty standing on upper floors.
 Old or poorly-builtstructures suffer considerable damage.
 Some well-builtstructures are slightlydamaged.
 Some cracks may appear on dikes,fishponds,road surface,or concrete
hollow block walls.
 Limited liquefaction,lateral spreading and landslides are observed.
VII

2.  Trees shake noticeably.
VIII Very Destructive
 People will find it difficultto even stand outdoors.
 Many well-builtbuildings are considerablydamaged.
 Concrete dikes and the foundations ofbridges are destroyed by ground
settling or toppling.
 Railwaytracks are bent or broken.
 Utility posts,towers,and monuments maytilt or topple.
 Water and sewer pipes maybe bent, twisted,or broken.
 Liquefaction and lateral spreading cause manmade structures to sink,tilt,
or topple.
 Numerous landslides and rockfalls occur in mountainous and hillyareas.
 Boulders are thrown out from their positions particularlynear the
epicenter.
 Fissures and faults rupture.
 Trees shake violently.
 Water splashes over dikes or the banks of rivers.
VIII, IX 5–6
IX Devastating
 People are forced to the ground.
 Most buildings are totallydamaged.
 Bridges and elevated concrete structures are toppled or destroyed.
 Numerous utilityposts,towers,and monuments are tilted,toppled,or
broken.
 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 commonlythrown out.
 River water splashes violentlyor slops over dikes and banks.
X, XI
7
X
Completely
Devastating
 Many trees are toppled,broken, and uprooted.
 Practically all man-made structures are destroyed.
 Massive landslides and liquefaction,large-scale subsidence and the
uplifting of land forms and many ground fissures are observed.
 Changes in river courses and destructive seiches in large lakes occur.