Richter magnitude scale degrees. formula_40 is mainly between 5 and 8. The Tsumura empirical formula: Where formula_42 is the total duration of oscillation in seconds. formula_40 is mainly between 3 and 5. The Tsuboi, University of Tokyo, empirical formula: Where formula_31 is the amplitude in micrometers. Richter magnitude scale The so-called Richter magnitude scale – more accurately, "Richter's magnitude scale", or just "Richter magnitude" – for measuring the strength ("size") of earthquakes refers to the original "magnitude scale" developed by Charles F. Richter and presented in his landmark 1935 paper, and later revised and renamed the Local magnitude scale, denoted as "ML" or
Logarithmic scale the value of a logarithm function. Here, a given logarithmic unit will be denoted using the notation [log "n"], where "n" is a positive real number, and [log ] here denotes the indefinite logarithm function Log(). Examples of logarithmic units include common units of information and entropy, such as the "bit" [log 2] and the "byte" 8[log 2] = [log 256], also the "nat" [log e] and the "ban" [log 10]; units of relative signal strength magnitude such as the "decibel" 0.1[log 10] and "bel" [log 10], "neper" [log e], and other logarithmic-scale units such as the Richter magnitude scale