Richter scale

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Measurement Seismometer Seismic magnitude scales Seismic intensity scales
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The Richter scale^[1] (/ˈrɪktər/), also called the Richter magnitude scale, Richter's magnitude scale, and the Gutenberg–Richter scale,^[2] is a measure of the strength of earthquakes, developed by Charles Richter in collaboration with Beno Gutenberg, and presented in Richter's landmark 1935 paper, where he called it the "magnitude scale".^[3] This was later revised and renamed the local magnitude scale, denoted as ML or M_L .^[4]

Because of various shortcomings of the original M_L  scale, most seismological authorities now use other similar scales such as the moment magnitude scale (M_w ) to report earthquake magnitudes, but much of the news media still erroneously refers to these as "Richter" magnitudes. All magnitude scales retain the logarithmic character of the original and are scaled to have roughly comparable numeric values (typically in the middle of the scale). Due to the variance in earthquakes, it is essential to understand the Richter scale uses common logarithms simply to make the measurements manageable (i.e., a magnitude 3 quake factors 10³ while a magnitude 5 quake factors 10⁵ and has seismometer readings 100 times larger).^[5]