snowfield vs thaw

snowfield

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

thaw

noun
  • a period of weather warm enough to melt that which is frozen 

  • The melting of ice, snow, or other frozen or congealed matter; the transformation of ice or the like into the state of a fluid; liquefaction by heat of anything congealed by frost 

  • a period of relaxation, of reduced reserve, tension, or hostility or of increased friendliness or understanding 

verb
  • To gradually melt, dissolve, or become fluid; to soften from frozen 

  • To gradually cause frozen things (such as earth, snow, ice) to melt, soften, or dissolve. 

  • To become so warm as to melt ice and snow — said in reference to the weather, and used impersonally. 

  • To grow gentle or genial. 

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