ice hole vs snowfield

ice hole

noun
  • A hole in the ice of a frozen body of water, often man-made with the scope of fishing. (This entry is a translation hub.) 

snowfield

noun
  • A large permanent expanse of snow on a mountain or at the head of a glacier. 

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