ice cap vs rink

ice cap

noun
  • An ice pack designed to be worn on the head. 

  • A permanent expanse of ice encompassing a large geographical area, e.g. in Earth's polar zones or at high elevation. 

rink

noun
  • A sheet of ice prepared for playing certain sports, such as hockey or curling. 

  • A building housing an ice rink. 

  • A team in a competition. 

  • A man, especially a warrior or hero. 

  • A surface for roller skating. 

  • A ring; a circle. 

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