churning vs upheaval

churning

noun
  • The act by which something is churned. 

  • The quantity of butter prepared (by churning) at one time. 

upheaval

noun
  • A sudden violent upset, disruption or convulsion. 

  • Disruptive change, from one state to another. 

  • The process of being heaved upward, especially the raising of part of the earth's crust. 

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