intensity vs magnitude

intensity

noun
  • The severity of an earthquake in terms of its effects on the earth's surface, and buildings. The value depends on the distance from the epicentre, and is not to be confused with the magnitude. 

  • Time-averaged energy flux (the ratio of average power to the area through which the power "flows"); irradiance. 

  • Can mean any of radiant intensity, luminous intensity or irradiance. 

  • Synonym of radiance. 

  • The degree of strength. 

  • The quality of being intense. 

magnitude

noun
  • A measure of the energy released by an earthquake (e.g. on the Richter scale). 

  • A number, assigned to something, such that it may be compared to others numerically 

  • An order of magnitude. 

  • The absolute or relative size, extent or importance of something. 

  • Of a vector, the norm, most commonly, the two-norm. 

  • The apparent brightness of a star, with lower magnitudes being brighter; apparent magnitude 

  • A ratio of intensity expressed as a logarithm. 

How often have the words intensity and magnitude occurred in a corpus of books? (source: Google Ngram Viewer )