Magnitude and intensity
Magnitude and intensity are parameters for quantifying the energy of an earthquake. Magnitude is calculated from the amplitude of the signal recorded on the seismogram, or from its duration, while the intensity is a qualitative estimate of the energy released by an earthquake. The MSK scale generally used in Europe has 12 degrees (from I to XII). A degree of IV characterises an earthquake felt by the population but which causes no damage, whereas earthquakes of intensity greater than V cause damage. Intensity and magnitude can be related to each other. For example, an intensity of VII corresponds to a magnitude of about 5.5.