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.

See related terms: amplitude,  arrival,  frequency,  phase,  trace

2. n. [Formation Evaluation]

The distribution of gamma ray energies, or the number of gamma rays as a function of gamma ray energy.

See related terms: activation log,  geochemical log,  induced gamma ray spectroscopy,  neutron interactions,  pulsed neutron spectroscopy measurement