**Symbol**: M / **Base data**: Earthquake.

The maximum amplitude recorded by a seismograph located 100 km away from the epicenter is measured in micrometers and the common logarithm of that figures is taken

**Expresses the size of the energy in the seismic center**

Seismic intensity is the size of tremors measured in various regions, but the magnitude is the size of the energy in the seismic center. There is a vast amount of energy, but it is expressed as a logarithm to shorten the number of digits. When magnitude increases by 1, this means that energy increases by 32-times. If magnitude increases by 2, this means 1000-times more energy.

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