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 Absolute magnitude Absolute magnitude is a measure of the luminosity of a celestial object, on a logarithmic astronomical magnitude scale. An object's absolute magnitude is defined to be equal to the apparent magnitude that the object would have if it were viewed from a distance of exactly 10 parsecs (32.6 light-years), with no extinction (or dimming) of its light due to absorption by interstellar dust particles. By hypothetically placing all objects at a standard reference distance from the observer, their luminosities can be directly compared on a magnitude scale. As with all astronomical magnitudes, the absolute magnitude can be specified