fissure vs ravine

fissure

noun
  • A long, narrow crack or opening made by breaking or splitting, especially in rock or earth. 

  • A groove, deep furrow, elongated cleft or tear between body parts or in the substance of an organ; a sulcus. 

  • A break or slit in tissue usually at the junction of skin and mucous membrane. 

  • A state of incompatibility or disagreement. 

verb
  • To split, forming fissures. 

ravine

noun
  • A deep narrow valley or gorge in the earth's surface worn by running water. 

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