Mercalli scale

seismology

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June 30, 2026

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The Mercalli scale is an earthquake intensity scale that describes the effects of seismic shaking in qualitative terms. It ranges from I (not felt) to XII (total destruction). Unlike earthquake magnitude scales, which measure the size of seismic waves recorded by seismographs, the Mercalli scale assesses the observed effects on people, buildings, and the environment. This makes it useful for understanding the impact of past earthquakes, even before seismographs were widely available. The scale is distinct from the Richter scale, which quantitatively measures an earthquake's magnitude based on seismic wave amplitude.123

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Charles F. Richter
…size and complemented the older Mercalli scale, which was based on an earthquake’s reported intensity. Richter also mapped out quake-prone areas in the United States, though he disparaged attempts at earthquake prediction. He wrote (with Beno Gutenberg) Seismicity of the Earth and Associated Phenomena (1949) and Elementary Seismology (1958). He…
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…size and complemented the older Mercalli scale, which was based on an earthquake’s reported intensity. Richter also mapped out quake-prone areas in the United States, though he disparaged attempts at earthquake prediction. He wrote (with Beno Gutenberg) Seismicity of the Earth and Associated Phenomena (1949) and Elementary Seismology (1958). He…
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earthquake
Intensity scales
…in North America is the Mercalli scale, as modified by Harry O. Wood and Frank Neumann in 1931, in which intensity is considered to be more suitably graded. A 12-point abridged form of the modified Mercalli scale is provided below. Modified Mercalli intensity VIII is roughly correlated with peak accelerations…
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…in North America is the Mercalli scale, as modified by Harry O. Wood and Frank Neumann in 1931, in which intensity is considered to be more suitably graded. A 12-point abridged form of the modified Mercalli scale is provided below. Modified Mercalli intensity VIII is roughly correlated with peak accelerations…
Read More