explosion vs upsurge

explosion

noun
  • A bursting due to pressure. 

  • A sudden outburst. 

  • A sudden uncontrolled increase. 

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

  • The sound of an explosion. 

upsurge

noun
  • A sudden strong rise or flow. 

verb
  • to surge up, or to become stronger or greater 

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