glaciation vs snowpack

glaciation

noun
  • A particular instance of glacier formation. 

  • The act of freezing. 

  • The process of covering with a glacier, or the state of being glaciated; the production of glacial phenomena; an ice age 

snowpack

noun
  • An accumulation of packed snow, usually the seasonal amount. 

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