An earthquake’s magnitude is a measure of the amount of energy released during the rupture of the rocks. The energy is released in the form of shock waves.

These waves are recorded by seismometers around the world and are the basis for calculating the earthquake’s magnitude.

The concept of magnitude was developed in 1935 in California by Charles Richter as a mathematical device to compare the size of earthquakes.

The magnitude of an earthquake is determined from the logarithm of the recorded amplitude of the waves.

Because of the logarithmic basis of the scale, each whole number increase in magnitude represents a tenfold increase in measured amplitude; as an estimate of energy, each whole number step in the magnitude scale corresponds to the release of about 31 times more energy than the amount associated with the preceding whole number value.