explosion vs outbreak

explosion

noun
  • A sudden uncontrolled increase. 

  • A sudden outburst. 

  • A violent release of energy (sometimes mechanical, nuclear, or chemical.) 

  • A bursting due to pressure. 

  • The sound of an explosion. 

outbreak

noun
  • A sudden increase. 

  • An eruption; the sudden appearance of a rash, disease, etc. 

  • Synonym of breakout (“escape from prison”) 

  • An outburst or sudden eruption, especially of violence and mischief. 

verb
  • To burst out or break forth. 

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