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 corresponds to absolute bolometric magnitude 4.74. Placing a radiation source (e.g. star) at the standard distance of 10 parsecs, it follows that the zero point of the apparent bolometric magnitude scale corresponds to irradiance . Using the IAU 2015 scale, the nominal total solar irradiance ("solar constant") measured at 1 astronomical unit () corresponds to an apparent bolometric magnitude of the Sun of −26.832. Following Resolution B2, the relation between a star's absolute bolometric magnitude and its luminosity is no longer directly tied to the Sun's (variable) luminosity: where The new IAU absolute magnitude scale permanently disconnects the scale from