Moment magnitude scale of formula_33 are the same for all earthquakes, one can consider as a measure of the potential energy change Δ"W" caused by earthquakes. Similarly, if one assumes formula_34 is the same for all earthquakes, one can consider as a measure of the energy "E" radiated by earthquakes. Under these assumptions, the following formula, obtained by solving for the equation defining , allows one to assess the ratio formula_35 of energy release (potential or radiated) between two earthquakes of different moment magnitudes, formula_36 and formula_37: As with the Richter scale, an increase of one step on the logarithmic scale of moment
Order of magnitude Order of magnitude An order of magnitude is an approximate measure of the number of digits that a number has in the commonly-used base-ten number system. It is equal to the logarithm (base 10) rounded to a whole number. For example, the order of magnitude of 1500 is 3, because 1500 = 1.5 × 10. Differences in order of magnitude can be measured on a base-10 logarithmic scale in “decades” (i.e., factors of ten). Examples of numbers of different magnitudes can be found at Orders of magnitude (numbers). Generally, the order of magnitude of a number is the smallest power