upheaval vs upthrust

upheaval

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

  • Disruptive change, from one state to another. 

  • A sudden violent upset, disruption or convulsion. 

upthrust

noun
  • An upward movement of part of the Earth's crust. 

  • Buoyancy. 

  • An upward thrust. 

verb
  • To thrust something upwards. 

  • To be thrust upwards. 

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