# Nomogram connecting source radius, stress drop, corner frequency, and seismic moment/magnitude

A nomogram similar to that published by M. Mahdyiar (1987) connecting source radius, stress drop, corner frequency, and seismic moment/magnitude assuming the Brune (1970, 1971) source model and a shear-wave velocity at the source of 3.5km/s (the results would be similar for the normal range of shear-wave velocity, about 3 to 4km/s).

Connect up two axes and where the line crosses the third axis is the result. An example line is shown for a stress drop (delta sigma) of 10bars and a moment magnitude (M) of 6, which gives a corner frequency (f0) of about 0.15Hz and a source radius (r) of 8km.

Created using pynomo using a type 1 nomogram with type 8 nomograms for each of the principal axes