disperse vs split up

disperse

verb
  • To break up and disappear; to dissipate. 

  • To scatter in different directions. 

  • To disseminate. 

  • To separate rays of light, etc., according to wavelength; to refract. 

  • To distribute throughout. 

adj
  • Scattered or spread out. 

split up

verb
  • Cease to be together, break apart from the group. 

  • separate, disassociate, cause to come apart. 

adj
  • Divided or separated. 

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