Moment magnitude scale Caltech seismologist Thomas C. Hanks noted that Kanamori’s scale was very similar to a relationship between and that was reported by where formula_8 is defined in newton meters (N·m). Although the formal definition of moment magnitude is given by this paper and is designated by M, it has been common for many authors to refer to as moment magnitude. In most of these cases, they are actually referring to moment magnitude M as defined above. Moment magnitude is now the most common measure of earthquake size for medium to large earthquake magnitudes, but in practice, seismic moment, the seismological parameter
Absolute magnitude using an absolute magnitude, one must specify the type of electromagnetic radiation being measured. When referring to total energy output, the proper term is bolometric magnitude. The bolometric magnitude usually is computed from the visual magnitude plus a bolometric correction, . This correction is needed because very hot stars radiate mostly ultraviolet radiation, whereas very cool stars radiate mostly infrared radiation (see Planck's law). Some stars visible to the naked eye have such a low absolute magnitude that they would appear bright enough to outshine the planets and cast shadows if they were at 10 parsecs from the Earth. Examples