rive vs sunder

rive

verb
  • To tear apart by force; to rend; to split; to cleave. 

  • To land. 

  • To burst open; explode; discharge. 

  • To use a technique of splitting or sawing wood radially from a log (e.g. clapboards). 

  • To break apart; to split. 

noun
  • A place torn; a rent; a rift. 

  • A bank or shore. 

sunder

verb
  • To break or separate or to break apart, especially with force. 

  • To part, separate. 

noun
  • a separation into parts; a division or severance 

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