This is very similar to astronomy where different magnitudes are assigned to the brightness of an astronomical object, depending on the range of wavelengths being measured.

My amateur interest in astronomy brought out the term 'magnitude', which is used for the brightness of a star.

I suggested that we might compare earthquakes in terms of the measured amplitudes recorded at these stations, with an appropriate correction for distance.

In every area of the world where there is earthquake risk, there are still many buildings of this type; it is very frustrating to try to get rid of them.

We would have been happy if we could have assigned just three categories, large, medium, and small; the point is, we wanted to avoid personal judgments. It actually turned out to be quite a finely tuned scale.

For example, some stars put out large amounts of energy in the infrared part of the spectrum, so that this can produce a different relative magnitude rating than using light energy from the middle of the spectrum.