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 and a difference of n magnitudes in absolute magnitude corresponds to a luminosity ratio of 100. For example, a star of absolute magnitude M=3 would be 100 times more luminous than a star of absolute magnitude M=8 as measured in the V filter band. The Sun has absolute magnitude M=+4.83. Highly luminous objects can have negative absolute magnitudes: for example, the Milky Way galaxy has an absolute B magnitude of about −20.8. An object's absolute bolometric magnitude represents its total luminosity over all wavelengths, rather than in a single filter band, as expressed on a logarithmic magnitude scale. To convert