The Richter scale is a measure of the intensity of an earthquake. The energy E (in joules) released by the quake is related to the magnitude M on the Richter scale as follows. How much more energy is released by a magnitude 7.6 quake than a 5.6 quake?
The magnitude of an earthquake is measured by the Richter scale. It is a logarithmic scale in which the magnitude is defined as the logarithm of the ratio of the amplitude of the seismic waves to an arbitrary minor amplitude.