Richter magnitude scale - a 4.0 to a 5.0 is 10 times greater

The Richter magnitude scale (also Richter scale) assigns a magnitude number to quantify the energy released by an earthquake. The Richter scale is a base-10 logarithmic scale, which defines magnitude as the logarithm of the ratio of the amplitude of the seismic waves to an arbitrary, minor amplitude.

As measured with a seismometer, an earthquake that registers 5.0 on the Richter scale has a shaking amplitude 10 times greater than that of an earthquake that registered 4.0, and thus corresponds to a release of energy 31.6 times greater than that released by the lesser earthquake.^[1]