Charles Francis Richter offered him a position as a research assistant there, where he began a collaboration with Beno Gutenberg. The Seismology Lab at the California Institute of Technology wanted to begin publishing regular reports on earthquakes in southern California and had a pressing need for a system of measuring the strength of earthquakes for these reports. Together, Richter and Gutenberg devised the scale that would become known at the Richter scale to fill this need, based on measuring quantitatively the displacement of the earth by seismic waves, as Kiyoo Wadati had suggested. The pair designed a seismograph that measured this displacement and
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