cliff vs talus

cliff

noun
  • A vertical (or nearly vertical) rock face. 

  • A point where something abruptly fails or decreases in value etc. 

talus

noun
  • A sloping heap of fragments of rock lying at the foot of a precipice. 

  • The bone of the ankle. 

  • The slope of an embankment wall, which is thicker at the bottom than at the top. 

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