1. n. [Geophysics]
Generally, a display of entities or properties according to magnitude. In geophysics, spectrum refers to a display of characteristics of a wavetrain or trace as a function of frequency, wavenumber, or arrival time. A common display of spectrum is amplitude as a function of frequency.
2. n. [Formation Evaluation]
The distribution of gamma ray energies, or the number of gamma rays as a function of gamma ray energy.
See: activation log, geochemical log, induced gamma ray spectroscopy, neutron interactions, pulsed neutron spectroscopy measurement