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MSK64 Seismic Intensity Scale

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The Medvedev-Sponheuer-Karnik scale of seismic intensity was widely used in Europe and India starting in 1964. The MSK64 scale is based on typical masonry structures, many of which are very old. MSK64 was revised in 1981 (MSK81) and was superseded by the European Macroseismic Scale in 1998.

During those years it was found that some of the behavioral effects in MSK64, such as "panic" and "fright," as well as most of the natural geological effects, were not consistently useful. People's responses to earthquakes depend on many variables besides the actual shaking, and seismic effects on the landscape are even less predictable given the differences in soils, bedrock and structural geology from place to place. Therefore MSK64 ratings of historical earthquakes should be used skeptically; if reliable details on building damage are known, they should outweigh the behavioral and geological evidence. Because it doesn't match up well with modern scales, the MSK scale is not included in the master table of intensity scales.

The MSK64 Scale

Degree Force Behavioral effects Structural effects Geologic effects
I Imperceptible Not felt    —    —
II Very light Felt sporadically    —    —
III Light Felt only by people at rest    —    —
IV Moderate Felt indoors, many awakened Windows vibrate    —
V Fairly strong Widely felt outdoors Interior plaster cracks, hanging objects swing, tables shift    —
VI Strong Fright Damage to chimneys and masonry Isolated cracks in soft ground
VII Very strong Many people flee their dwellings Serious damage to buildings in poor condition, chimneys collapse Isolated landslides on steep slopes
VIII Damaging General fright Many old houses undergo partial collapse, breaks in canals Changes in wells, rockfalls onto roads
IX Destructive Panic Large breaks in substandard structures, damage to well-constructed houses, underground pipe breakages Cracks in ground, sand eruptions, widespread landslides
X Devastating General panic Brick buildings destroyed Rails twisted, landslides on riverbanks, formation of new lakes
XI Catastrophic    — Few buildings remain standing, water thrown from canals Widespread ground disturbances, tsunamis
XII Very catastrophic    — Surface and underground structures completely destroyed Upheaval of the landscape, tsunamis
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