ice floe vs mountains

ice floe

noun
  • An ice stream (ice flow), a type of fast moving glacier 

  • An ice dam (ice jam), a blockage of ice in a river starting with an ice floe in the river. 

  • Any type of sea ice not attached to land, drift ice. 

  • A flat mass of floating ice, smaller than an ice field. 

mountains

noun
  • mountain range 

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