describe what is meant by the magnitude of an earthquake
Richter magnitude scale The Richter magnitude scale (ML, also Richter scale) assigns a magnitude number to quantify the size of an earthquake. The Richter scale, developed in the 1930s by Charles Francis Richter, is a base-10 logarithmic scale in order to cover the huge range of earthquakes. It defines magnitude as the logarithm of the ratio of the amplitude of the seismic waves to an arbitrary, minor amplitude, as recorded on a standardized seismograph at a standard distance.