Medvedev–Sponheuer–Karnik scale
The Medvedev-Sponheuer-Karnik scale (MSK-64) is a macroseismic intensity scale used to measure the effects of earthquakes on humans, objects of nature, and structures.
The scale was first proposed by V. Medvedev (USSR), W. Sponheuer (East Germany), and V. Karnik (Czechoslovakia) in 1964 and became widely used in Europe and the USSR. It received minor modifications in the mid-1970s and early 1980s. The European Seismological Commission (ESC) used MSK-64 as a basis for the development of the European Macroseismic Scale, which has been adopted in 1996 and is now a European Union's de facto standard for evaluation of earthquakes.
MSK-64 is still being used in Russia and other member countries of the Commonwealth of Independent States.
The Medvedev-Sponheuer-Karnik scale is somewhat similar to the Modified Mercalli (MM) scale used in the United States. Just like the MM scale, MSK-64 has 12 levels of seismic intensity:
| I. Not felt | Not felt, registered only by seismographs. No effect on objects. No damage to buildings. |
|---|---|
| II. Scarcely felt | Felt only by individuals at rest. No effect on objects. No damage to buildings. |
| III. Weak | Felt indoors by a few. Hanging objects swing slightly. No damage to buildings. |
| IV. Largely observed | Felt indoors by many and felt outdoors only by very few. A few people are awakened. Moderate vibration. Observers feel a slight trembling or swaying of the building, room or bed, chair etc. China, glasses, windows and doors rattle. Hanging objects swing. Light furniture shakes visibly in a few cases. No damage to buildings. |
| V. Fairly strong | Аelt indoors by most, outdoors by few. A few people are frightened and run outdoors. Many sleeping people awake. Observers feel a strong shaking or rocking of the whole building, room or furniture. Hanging objects swing considerably. China and glasses clatter together. Doors and windows swing open or shut. In a few cases window panes break. Liquids oscillate and may spill from well-filled containers. Animals indoors may become uneasy. Slight damage to a few poorly constructed buildings. |
| VI. Strong | Felt by most indoors and by many outdoors. A few persons lose their balance. Many people are frightened and run outdoors. Small objects may fall and furniture may be shifted. Dishes and glassware may break. Farm animals may be frightened. Visible damage to masonry structures, cracks in plaster. Isolated cracks on the ground. |
| VII. Very strong | Most people are frightened and try to run outdoors. Furniture is shifted and may be overturned. Objects fall from shelves. Water splashes from containers. Serious damage to older buildings, masonry chimneys collapse. Small landslides. |
| VIII. Damaging | Many people find it difficult to stand, even outdoors. Furniture may be overturned. Waves may be seen on very soft ground. Older structures partially collapse or sustain considerable damage. Large cracks and fissures opening up, rockfalls. |
| IX. Destructive | General panic. People may be forcibly thrown to the ground. Waves are seen on soft ground. Substandard structures collapse. Substantial damage to well-constructed structures. Underground pipelines raptured. Ground fracturing, widespread landslides. |
| X. Devastating | Masonry buildings destroyed, infrastructure crippled. Massive landslides. Water bodies may be overtopped, causing flooding of the surrounding areas and formation of new water bodies. |
| XI. Catastrophic | Most buildings and structures collapse. Widespread ground disturbances, tsunamis. |
| XII. Very catastrophic | All surface and underground structures completely destroyed. Landscape generaly changed, rivers change paths, tsunamis. |
Other seismic intensity scales
Unlike the magnitude scales (such as the Richter scale), which measure the amount of seismic energy released at the hypocenter of the earthquake, intensity scales are used to evaluate the effects of ground motions on people, buildings, and objects of nature. Below is an incomplete list of other seismic intensity scales.